Thursday, February 28, 2008

Review: Sigma 600mm f/8 Reflex (Part 1 of 2)

Finally, the time has come for my full Sigma 600mm f/8 Reflex review. If you aren't a regular reader of my blog and you'd like the know the back story, check out all the posts marked Sigma600mm.

Of course, if you are too lazy to read the previous posts, let me give you a recap. First, I was looking for a long (400mm+) lens for bird photos and did a bunch of searching on eBay (here are some other lenses I considered). On a whim, I bid on and won a Sigma 600mm f/8 for $78 + $14 S/H. The Sigma 600mm is a well-regarded version of those infamous mirror/reflex lenses (or, officially, catadioptric lenses). My Sigma is an FD lens, so I also purchased an FD-EOS converter (review) for $36 including shipping. I've also described the process, advantages, and drawbacks of adapting FD lenses to EOS/EF cameras.

Sadly, when the lens arrived, it had some fungus on the main mirror, but it wasn't enough to return it and I don't think it is a major detriment to image quality. I did ask the buyer for a $15 refund, so my ultimate price for the lens was $77. Since then, I've shot a decent amount with the lens (maybe 700 shots over 10 hours) and I'm ready to give my review. And, in true backwards fashion, I'll start with the...


Let me make my advice real simple for you if you are considering the Sigma 600mm for a digital camera (I don't have any experience with it on a film camera, so you're on your own there):

  • The Sigma 600mm f/8 does have substantially better image quality than an up -sampled Canon 70-200mm f/4. That's a huge weight off of me, because I was very concerned about what this review said.
  • The lens has high build quality but it is still a mirror lens and has plenty of limitations.
  • It is VERY hard to get decent pictures out of the lens since it has narrow depth of field, is very sensitive to camera shake (even on a tripod since it has an equivalent focal length of 1000mm), and is relatively slow (f/8). Expect to do a lot of shooting at ISO 400+ and toss a lot of soft images.
  • If you are strapped for cash but need the reach and you can get a Sigma 600mm for $150 or less (in a mount that fits your camera or can be adapted to your camera), do it. You won't be sorry.
  • Don't pay more than $200 for one in any mount. Most of the EOS mounts, because of rarity, go for upwards of $250. I don't think it is worth it, because used 400mm refractive lens are available for $300+ without most of the limitations of mirror lenses.
Here's a widget that shows the 600mm Sigma lenses available on eBay right now:

The Minolta version is probably the cheapest and most popular version available (and there are Minolta to EOS converters available). The Canon FD mounts are pretty cheap too. Not all the lenses are black either -- I've seen auctions for at least one white one and one greenish/gray one. There may be different versions of the lens out there, but as far as I know, they are all optically identical and good quality.

Okay, now that I've given you the dessert first, how about dinner...

Physical Characteristics:

The lens itself is built like a tank: metal, well-toleranced, and heavy. Not solid cat heavy or refractive 500mm f/4 heavy, but still pretty heavy. I guess the weight needs to be put into perspective: it is heavy compared to my Tamron 17-50mm, but still under two pounds, and nowhere near the weight of a quality refractive 600mm lens.

The only functional part of the lens (since it lacks both autofocus and aperture control) is the focus wheel, which turns a total of a little over 180 degrees with nice action (smooth and well-damped). The damping has a strange response in the middle of the range (almost like air gets trapped or something) but the effect is only noticeable when you move the focus quickly. I never notice this when I'm actually using the lens. Also, the end of the lens does rotate with the focus wheel, but a front polarizer is pretty unrealistic with this lens anyway!

The Sigma 600mm reflex does include a built-in tripod mount which I really haven't had much use for. Since the front of the lens is so light, the tripod mount isn't that much of an improvement over just mounting the camera on the tripod. In my case, my tripod doesn't mount well at all to the lens mount (it rotates too easy; an issue with my tripod, not the lens mount). If you have a smaller camera like a Digital Rebel, you might prefer the tripod-mount. It allows 90 degree rotation to portrait mode.

The lens does include a filter holder and my package included a case and five 22.5mm filters of various shades. The filters are pretty useless if you are shooting on digital and I'm not sure if a polarizer would even work in the back position. On mine, I actually removed all the filters, including the clear/UV filter. Why put more optical elements in the light path if you don't need them?

My version of the lens has an old FD mount (breech-lock). It mounts securely and has zero interface with the camera since it lacks a diaphragm. Mounted on the camera, it is pretty solid although you can twist it slightly due to the FD-EOS converter. It doesn't cause problems in normal use though, except...

After taking it out a number of times, I started to notice excessive sloppiness when I rotated the lens, to the point where it had a loose feeling even when I was doing fine focus. At first, I thought it was the mount loosening up, but then I realized that the back of the lens (held on by three tiny screws, in the shadows of the image above but easy to see below) was actually loosening up. So, I took it to work where I had some jeweler's screwdrivers and went ahead and took the back off to see what it looks like (and to check for a huge mold infestation). This is what I saw:

I think this is the back of the mirror, but I didn't go any further with disassembly because that seal (which was already pulling out slightly) didn't look like it'd go back in easy. So, I put it back together, screwed the screws back in tightly, and everything works fine now.

So, to summarize, the Sigma 600mm is a really well-built lens. Solid, everything is metal (even the lens hood!) and there's no slop in it at all.


The next question, and probably the top question for most people who find this page, is how does the lens perform?

To test performance, I was originally going to go outside and post a target across my yard to get shots and compare them to the Canon 70-200mm F/4 USM. But then it rained. And rained, and rained... So, instead, I just taped a target (something out of a catalog my wife had; as luck would have it I yanked out the religion page) to a cupboard door in my kitchen and set up the tripod on the far side of the living room. Total distance is about 25 feet or so.

To guarantee only a test of optimal lens sharpness, I used a flash to illuminate the target from below, and put the 20D on a tripod with mirror lockup and the self-timer enabled. For each equipment combination I took the best results (focus, etc) of multiple images to really look at optimal performance. All shots were at 1/250s (sync speed), f/8, ISO 100, converted straight from RAW with no levels or sharpening. All Sigma shots used the FD/EOS converter but the optical element is the extra variable (did I include it or not).

The three full frame setups are (click to see them larger, but not the 100% crop):

Full frame Canon 70-200mm f/4 USM (CANON)

Full frame Sigma 600mm f/8, no corrective lens (SIGMA_A)

Full frame Sigma 600mm f/8, corrective lens (SIGMA_B)

As you can see, the Sigma, as expected, has a much smaller field of view. Both versions of the Sigma are darker than the Canon, which may be a result of the FD/EOS converter. And the corrective lens has a smaller field of view and darker image than with the corrective lens removed. I didn't measure the drop in light intensity scientifically but it is probably 1/3-1/2 stop without the corrective lens and maybe a full stop with the corrective lens. Also note the difference in contrast between the Sigma and the Canon, although contrast can be easily fixed in post (with the corresponding increase in image noise).

I did measure the distance between two features, in pixels, on all the images and compute an effective focal length. Assuming the Canon is truly 200mm at full zoom:
  • Canon: 200mm (320mm effective on 1.6x crop sensor)
  • Sigma w/o corrective optics: 665mm (1064mm effective)
  • Sigma with corrective optics: 785mm (1256mm effective)
These rough calculations mean the Sigma is easily over 1000mm effective focal length on a crop body like the 20D. That's intense magnification! It does result in some difficulties when using the camera, which I'll get to in the handling portion of the review.

The Sigma also has a slight vignette to it, even on a small sensor camera like the 20D. I expect the vignette would be much worse on a full frame camera or film, but it isn't objectionable at all for my purposes (I sort of like it, actually). It'd be easy to remove if you wanted to. For example, in the helicopter image below, the blue intensity at the corner is about 85% of the blue intensity in the center.

Next, the real meat: at a 100% crop, how does the Sigma compare to the Canon? Below is a 100% crop from the Canon and the Sigma without the corrective lens:

100% crops: Canon on the left, SIGMA_A on right

The Canon clearly has better contrast and sharpness but the Sigma can resolve finer detail. How about up-sampling the Canon to directly compare at the same resolution?

Left: Upsampled Canon, Right: SIGMA_A 100%

Again, better contrast in the Canon, but the Sigma can clearly make out a lot better detail. Instead of just a rough idea of the words, you can actually read them and make out the edges of the letters. The tiny text at the bottom is a small blob on the Canon but readable on the Sigma.

Overall, I'd say the Sigma's sharpness is probably similar to a decent 400mm refractive lens like the Sigma 400mm f/5.6. Definitely, the Sigma isn't nearly as sharp as the Canon, but the 300+% increase in focal length (and 900+% increase in effective pixels) makes up for the lack of sharpness. The Sigma 600mm f/8 can get shots that you can't get with the Canon 70-200mm F/4. It'd be interesting to try the Canon with a teleconverter, and if I get one, I'll update this comparison.

The final question is whether the optical element in the FD/EOS converter hurts image quality as I hypothesized earlier. The addition of the optical element turns the converter from an effective extension tube to an effective teleconverter (with the accompanying increase in focal length and decrease in aperture). To test, I upsampled the sample without the optical element and compared it to the 100% crop with the optical element:

Left: SIGMA_A upsampled, Right: SIGMA_B 100% crop

Aside from the decrease in brightness, if you look closely you can see the optical element does hurt image quality slightly (the edges of the letters aren't quite as sharp). While the decrease in sharpness is minor, I recommend using the lens without the optical element whenever possible.

The other major conclusion is that the Sigma 600mm f/8 Mirror lens has a substantial advantage over an upsampled 200mm, but probably no advantage (and many disadvantages) compared to the 400mm f/5.6 lenses. So, again, if you can't afford a 400mm+ lens and you can get the Sigma for cheap (<$150) it is worth it. But, I've got to warn you now, the combination of the monster focal length and the catadioptric construction makes the lens really, really hard to use effectively.

To Be Continued...

This post has taken forever to write, and it will take a little longer to be finished. I'm going to split the handling of the lens (along with lots of sample shots) into a separate post to keep this from getting too long. Hopefully I'll get it up in the next day or two!

Thursday, February 21, 2008

Lunar Eclipse

There was a total lunar eclipse last night. Of course, I didn't find out about it until I was at work, sans camera, and still trying to finish up my paper.

I suppose if I had been home, I still would have been frustrated by the constant light cloud cover. My wife got some shots though, and some of them look pretty good.

As a substitute, I whipped up the image above. After all, a lunar eclipse just looks like the moon with a bite out of it, right?

Update: Here's a great lunar eclipse shot on Flickr. Of course, they used a telescope. Cheaters!

Update #2: Here's one of my wife's shots. The wiggly line going across the eclipse is a plane! The fact the track is wiggly leaves me to believe that my tripod is pretty crappy!

Tuesday, February 19, 2008

Tour of California Prologue

It is a little known fact that I was into bicycling when I was in high school. I never did any racing, but I was a bit of a fanatic and completed a century around Cayuga Lake when I was in my teens. In college, I did a little bit of mountain biking, but sadly my knee got funky so I haven't been doing much biking anymore (other than transportation).

Anyway, there's no real point of the story above, except I don't follow cycling at all now. But when the Amgen Tour of California rolled through Stanford (or, more precisely, began with the Palo Alto-Stanford Prologue), I figured I might as well go take some pictures. Especially since the lab (where I've been spending a ton of time lately working on two papers) is two blocks away from the finish line.

When I got there, there were a ton of people around the oval. As always, click to see the images larger.

Since my goal was just to get a work break and exercise my shutter finger I didn't bother elbowing my way to the railing around the course. I got a few decent shots of the riders but quickly got bored. If I followed racing, I'm sure I'd be a lot more interested in shooting each rider as they came through.

I definitely have a lot of respect for sports shooters. A ton of waiting, and then only a few moments to get the shot you want. The prologue wasn't too bad because each rider comes at you all alone and it is easy to get a clean shot. But they move fast. A little slow on the shutter and you'll miss it. I was definitely glad I had 5 fps on my 20D.

The one below is notable because it is a 100% crop from an image with my Canon EF 70-200mm f/4L USM. I've been using the Sigma 600mm f/8 so much I've forgotten how sharp a good lens is. Awesome deal, and the lens can make a pile of sh...eep look like a pile of sheep with amazing contrast, sharpness, and color.

Of course, I got bored pretty quick. Only so many "rider speeds around a turn with fans watching" pictures I can take before I need to move on. I did see a VTU (Very Tall Unicycle) though:

And then I decided to do some motion panning on the riders. I like how these came out, although there is a lot of luck involved in timing the rider to be framed in the gaps in spectators. I found an area where the far side of the course was in shadow and the near side spectators were facing the sun which helped.

Of course, I wasn't the only one shooting the race. I've NEVER seen so many expensive lenses in one place before, with everyone and their grandma toting around L-glass (or the Nikon equivalent). I saw monopods, tripods, rifle-grips, monster lenses, fill flash, you name it, and that's just the amateurs. You could spot the pros (at least the ones who got official clearance) by their vests:

That's it, I need to get back to finishing this $^%^&^* paper.

Here's the finish line (or maybe, more appropriately, some spectators looking in the general direction of the finish line):

Thursday, February 14, 2008

Lenses on eBay: Two Negative Experiences

Sorry for the long delay in posts. Life has gotten really busy in both of my jobs, so post frequency will likely decrease during the rest of February. The Sigma 600mm review is ready to be written, I just need to find the time to do it.

In my post A Guide to Buying Lenses on eBay, I mentioned that I'd had a few problems buying lenses. Oddly enough, out of the six lenses I've purchased, it has only been the last two Canon FD lenses that I've had trouble with: a Sigma 600mm f/8 Mirror and a Canon 100mm f/4 Macro.

Sigma 600mm f/8 Reflex

As I mentioned earlier, this was an impulse buy that I didn't fully research before bidding. More specifically, I didn't directly ask the seller if the glass was clear. I knew that the seller was inexperienced and would have normally asked, but I had decided not to buy it and only changed my mind less than a minute before the auction ended since the price was so cheap. FYI, I got the lens for $78 + $14 S/H, a very good price for the FD-mount version.

But, not asking the fungus question ended up coming back and biting me in the... derrière.

95% of the time, lenses on eBay are fungus free even if they don't specifically mention it in the listing. In this case though, the lens really was in great condition, except the main mirror had some spots of fungus on it. The outside of the lens is pretty much mint, which is probably why the seller didn't notice the fungus on the inside (I assume).

Here's a (soft) overview image to give you an idea of scale. The fungus/mold dots are on the upper part of the mirror (which is reflecting the blue sky in the middle of the image. There's two spots on the very edge and one lighter spot farther into the mirror between the other two.

Here's a detail image with better focus. Again, there's a nasty one on the left (almost looks like it ate through the mirror) a light one in the center and another light one on the right edge.

When I tilted the lens in the sunlight, I got a real idea of the damage. The dark spot on the left fans out quite a bit, the center one is larger than it seemed, and the one on the right is much larger than it initially appeared (note that a lot of it is obscured by the shadow edge). Note how the fungus spreads on the mirror (or any lens) outside of what you can see. From what I've heard, often fungus often etches the mirror permanently.
BTW, I know the lens looks super dirty, but in reality it is very clean. This angle (with the sun beating on it) really shows EVERYTHING. Also, the best way to avoid fungus is to store the lens as dry as possible (like adding a desiccant to your camera bag). The best way to remove it is... well, I'm still working on that.

So, after I realized the fungus problem, I was a little torn. On one hand, the seller stated the lens condition was 'mint' and fungus is obviously not a mint situation. I was also willing to keep the lens; the fungus shouldn't substantially damage image quality. And, in my mind, the seller obviously didn't know the fungus was there. I did withhold posting positive feedback because I knew that was my only leverage in this situation.

So, after some debate, I decided to ask for a partial refund. I actually felt quite bad doing it since it seemed a bit like feedback blackmail, but the lens condition is obviously not mint. FYI, if I'd actually asked if the glass was clear and the seller told me it was (like usual) then I would have very forcefully asked for a large percentage rebated.

In this case, I sent the seller an e-mail directly to her account:

Hi xxxx,

I received the lens last week and it is in great shape as you said, except... It has a small amount of fungus/mold on the main mirror. I've attached images to show you what I mean -- in 6569 you can see the three-four spots of mold, and in 6573 you can see the spread of the mold across the mirror for the spots.

I honestly think you didn't know about the fungus (which usually grows if there is moisture in/on the lens and it is stored for a long time). But you did list the lens as MINT in the listing and I definitely would not have spent so much if I had known about the fungus. Fungus is hard to get rid of, often permanently damages the lens, and significantly lowers the resale value. In this situation, I doubt it impacts the image quality much, but I'm going to have to take some steps to kill it and clean it up.

I'd still like the lens, but I'd like to ask you for a partial refund based on the condition of the lens, maybe $15. Are you willing to do this?

Thank you for your time. I apologize to hassle you with this and I firmly believe you had no knowledge of the damage.


PS If you have other lenses from your Dad's collection I recommend checking them for fungus too. Often, growth can be avoided by putting a silica gel in with the equipment to absorb moisture and changing it every once in a while.
I got no response, but a few days later, I got a message asking for feedback which indicated she hadn't received the e-mail above (SPAM filter). So I resent it through eBay and she immediately wrote me back:
$15 is VERY reasonable. I appreciate you getting back with me, as I had NO IDEA of the mold issue. It was stored in a very dry, dark place, but I can't speak for how it was stored prior to me inheriting it from my father. He's always so good about those things. Anyway, thanks for getting with me to work things out! Just send me an invoice for the $15.00 and I will be more than happy to pay it right away! Thanks again!
So, after that, everything went smoothly. Ultimately, I paid $92-15 = $77, including shipping, for a slightly fungus-damaged lens. I'm quite happy with the way things turned out (maybe I should have asked for a larger refund?) and I gave her positive feedback. My plan with the fungus is to keep an eye on it and if it gets any worse, I'll open the lens and figure out how to clean it. At this point though, it isn't worth the risk of damage to clean it. I did irradiate it in the sun for a few hours so hopefully that will stop the growth.

Canon 100mm f/4 Macro

The other eBay problem I've had is with a Canon 100mm f/4 Macro (FD-mount) I purchased Jan 20th for $50 + $15 S/H (a really good price).

The problem is, it hasn't arrived yet. Here's the tracking info on the lens:
Label/Receipt Number: 0479 7634 5650 3603 3692 Detailed Results:
  • Acceptance (APC), January 22, 2008, 1:06 pm, MONTROSE, CO 81401
  • Undeliverable as Addressed, January 25, 2008, 4:15 am, MOUNTAIN VIEW, CA 94043
  • Processed, January 29, 2008, 10:05 pm, DENVER, CO 80217
  • Processed, February 08, 2008, 5:03 am, SAN FRANCISCO, CA 94188
  • Processed, February 11, 2008, 6:57 pm, DENVER, CO 80266
Yeah, seriously. So it got here, had a bad address on it or something, went back to Colorado. Sat around somewhere for almost two weeks, went back to SF, then went back to Colorado. What the hell is going on?

The seller told me he'd send it out as soon as it got returned to him. But it has yet to arrive back after three weeks. I have to assume the seller screwed something up when he sent it out (he said a bunch of other items he mailed had similar problems) but I have to place some blame on the USPS too. I'd call them to track it down, but the seller is the only one that can do that. The seller did offer me a refund, but at this point, I'm fine waiting for the lens since I got a really good deal on it.

That is, assuming the lens doesn't get stuck in CO for another couple of weeks.

Update 2/19: The Canon 100mm f/4 finally arrived (I had gotten notice on Friday that the seller had received it from the USPS and sent it out again). I expect the problem was the seller put my house number as 722 instead of 772 (which is surprising, since he included a shipping list with the correct address, and you'd think he'd correct the address after the first delivery problem). I'm lucky it found my house the second time around. The condition is pretty rough, but for the price, it seems good. I'll clean it up and post a review in the next few weeks once I've spent some time with it.

Wednesday, February 6, 2008

A Monster Mirror Lens

I was doing a quick web search today when I stumbled upon the 1000mm Carl Zeiss Mirror f/5.6 lens, a pure monster. It fits the Pentacon Six, a medium format camera sold until the early '90s by Pentacon GmbH. The company currently makes digital point and shoots under the brand Praktika.

Anyway, I would have loved to include an image or two here, but the site is pretty clear about copyright issues. So let me paint you a picture instead: 31 lbs (14 kg), a lens cap the size of a dinnerplate, switchable filters actually sealed inside the lens, and amazing images. If you want to waste a little time, click on over and check it out:

  • Overview page with some sample images.
  • Later comparative review consisting of pages: [1] [2] [3] [4]
    • If you look at one page, look at the second -- it includes some great shots (including a full camera sitting inside of the lenscap).
Obviously, this isn't a practical lens since most tripods can't even support it, but it was really cool to see a really good quality 1000mm reflex lens. And, at 1000mm, the f/5.6 aperture is quite amazing.

Tuesday, February 5, 2008

A Guide to Buying Lenses on eBay

Yup, that's my Sigma 600mm f/8. The review is coming... slowly. I just realized today that the back panel is loose, but I don't think it is anything that I can't fix with some jeweler's screwdrivers. Too bad I don't have any here! Needless to say, I have to postpone the comparison shots I was planning on doing today (since it was the first sunny day that I'm home in two weeks).

Instead, I'd like to provide a brief guide to buying used lenses on eBay. I've bought a total of six lenses on eBay (Tamron 70-300mm f/4-5.6, Tamron 17-50mm f/2.8 (new), Tamron 19-35mm f/3.5-4.5, Sigma 600mm f/8, Nikkor-H 50mm f/2.0, Canon 100mm f/4 Macro) plus countless other items (extension tubes, a 20D, FD converter, reversing ring, SB-20 flash, etc). So, I'd like to think I know a little about researching and purchasing lenses in auctions.

Please note that this isn't a guide to using eBay; there are plenty of good resources out there. So today, I'll focus on how to avoid making a mistake when buying a used lens. The good news is that 90% of auctions are good deals and you won't have any regrets. It's avoiding that other 10% that is key.

Before You Bid:

Before you bid, make sure you do your research. What research is needed? Well, follow these steps:

  1. Know your camera brand and mount. A lens is nothing more than an expensive paper weight if it doesn't fit your camera, and this is the number one mistake new buyers make (for example, buying a manual focus Canon FD mount lens instead of an autofocus Canon EF mount lens, for example). It is also worthwhile to look at the mount of one of your existing lenses so you can quickly spot the correct mount in auction pictures.
  2. Know what your are willing to pay. Lenses are expensive, so know your financial limits. An F/4 lens longer than 300mm isn't going to happen for under $500.
  3. Know what lens(es) you want. This is probably the hardest thing, but take some time and do a broad search for available lenses based on your needs. For Canon EOS shooters, LensPlay (by Bob Atkins) has a searchable database of most of the available EOS mount lenses including approximate costs. Ken Rockwell has a similar database for Nikon lenses.
  4. Look up reviews for the lenses. Google is a great tool, just plug in the lens name and add review to the search string and you'll get a pretty good list of available reviews. Ideally, you'll find a review that directly compares the lens to competitors and provides example images. If the lens is available new, it is worth checking on Amazon (Lenses at Amazon). Amazon reviews are sometimes junk, but you can usually figure out the basic quality of common lenses. I've also got a number of reviews of common budget lenses on this site.
  5. Repeat steps 3 and 4 until you've got a short list of used lenses that will meet your needs. The better informed you are before you bid, the less likely you will be to win an auction and regret it later.
  6. Know the going rate of the lenses you are interested in. I used to use the completed listings search at eBay, but it only searches the previous week. I've found Terapeak's free search is much more useful because it lets you search listings for the last month! Get an idea of the average selling price, the maximum, and the minimum. Ideally, you'd only bid up to the average selling price unless you needed the lens in a hurry. If the lens is available new, check that price too; sometimes new lenses are only slightly more expensive than used lenses (like the Canon 70-200mm f/4; you should probably buy that one new since used prices are so high).
  7. Know the rarity of the lens. For very rare lenses, you need to be willing to be more aggressive with your bidding because another one might not pop up for months. Luckily, few budget lenses are this rare.
  8. Write the information down. This seems silly, but you never know if you'll stumble on an auction right before it ends and you'll need to make a quick decision (like my Sigma 600mm 'oops'!).
This seems like a lot of work, but it doesn't actually take long once you know what you are doing. Plus, if you are a gadget guy like me, it is kind of fun! Obviously, the more expensive the lens, the more research you should do. My overview of super telephotos can give you an example of the type of research I go through before I make a purchase (although I usually narrow down my options a lot more). The main thing is to have a written record because bidding sometimes lasts weeks and you can easily forget what your conclusions were.

When You Bid:

My general theory of bidding on eBay is this:

Factor everything into the maximum amount I'm willing to bid.

Or, put another way, everything about an auction has a monetary value. For instance, suppose my research tells me that a Tokina 400mm f/5.6 AT-X SD sells for between $200-$300. So, for a mint lens with amazing pictures and a seller with perfect feedback, I might pay $275 or more. If the images aren't clear enough to see anything, I'll lower my max bid by $20-50. If the lens has dings or usage issues, I'll lower it further. If the seller doesn't answer e-mails, I'll lower my max bid even more. If the lens is very rare and no other lenses are posted, I'll be willing to bid a little more.

Of course, I establish this maximum bid for each auction as soon as I can and update as I get each piece of information. There's no set equation I use, just a general sense. And, of course, I don't actually place the bid until close to the auction end time because I want to be able to change my mind and not be locked in to the bid. Usually, I'll go through the searches and add items to my watch list, making a note about my maximum bid as I go.

So, here's a list of things to take into consideration when you are determining how much to pay for an item:
  • Lens condition. This one is obvious, but many sellers won't explicitly mention no scratches or fungus. If they don't, ASK THEM. Unless the auction has perfect pictures and states the glass is completely clean, I'll always send them a quick message like, "Hi! Does this lens have any major issues, like fungus, mold, cloudiness, or dust?" If they don't answer me, I always assume the worst and downgrade my estimate accordingly.
  • Seller responsiveness. Even if everything is listed on the auction, I'll still ask a quick question of the seller. If they don't respond or have an off-topic response, I take that into consideration. Remember, once you send the money, you are at the seller's mercy. If they can't even respond to e-mails, how quickly do you think they'll pack up the lens and mail it out?
  • Obvious mistakes in the auction. I've gotten a ton of deals from eBay because sellers don't know camera lenses. But that can hurt you too -- they may not know that something is wrong with it. Many, many lenses are sold by relatives who know nothing about photography. Again, I'll ask questions (about fungus or scratches) and explain what to look for if needed.
  • Crappy pictures. Sellers are supposed to be photographers, right? Well then, why do they often put up near-useless pictures? If I can't see the lens, I'm not willing to pay as much for it. I will ask to see higher resolution pictures and examples if possible.
  • Poor or very little feedback. If someone has substantial negative feedback (more than 1%) or very few sales (especially if all were recent or all were far in the past), I'm going to adjust my maximum value downwards. Even though PayPal gives you buyer protection, it is not a fast system and the hassle costs you money. More risk to me = less value to me.
  • High shipping costs. A favorite tactic of many sellers is to add profit into the shipping and handling charges. Unless the lens is a monster, shipping costs generally aren't going to be much more than $10 for priority mail or similar within the continental United States. Question anybody who has S+H charges over $20. Remember, a $0.99 lens with $20 shipping is basically a $21 lens to you.
  • Sales tax. Usually not an issue for used lenses, but you will have to pay tax is the seller is a business in your state. Five cents or more on every dollar can add up quickly!
  • International sellers. (USA-centric here) There is inherent risk with international sellers -- poor package tracking, exchange rates, longer delivery time, etc. If you can find a deal overseas, great! But don't pay too much! Obviously, if you don't live in the USA, then most of your purchases will be international.
Of course, some times I'll decide to avoid a certain lens and take it off my watch list (or leave it on with a note so I don't mistakenly go for it later). The main reasons not to buy a lens:
  • Any major drop damage. Includes major dents or bends in the lens which could change the straightness of the lens. Also includes cracked glass. If the drop was hard enough to bend the filter threads (which I see often), it could have damaged things inside the lens too.
  • Anything marked 'for parts'. Unless you are like fixing small mechanical things and are willing to buy another lens for parts to fix the first.
  • Excessive scratches, fogginess, or almost any fungus. A few minor scratches aren't a big deal, they won't change image quality. Likewise a few dots of fungus. But, remember, fungus will spread and if you can't kill it, you'll have to clean it. Fogginess or oil leakage inside the lens is also just as troublesome. This is where a clear image through the lens will make you feel safe. Remember: lenses don't lose value over time as much as cameras or other items. In a way, each lens is an investment, and these blemishes will significantly impact resale value.
  • Anything that looks suspicious (like crappy images that seem to show scratches or fungus) and the seller doesn't respond to questions. I'm willing to downgrade my price for the risk, but sometimes the risk is just too much.
  • Any time you get a bad feeling about a seller. We have little voices in the back of our head for a reason (well, most of us). If you aren't getting good vibes, wait for another auction.
  • Anybody who doesn't accept PayPal. PayPal allows buyer protection (you'll get reimbursed if the seller tries swindle you). Almost every seller takes it, so when a seller doesn't, you should be very suspicious.
The last part of this section will be a checklist for bidding and winning auctions. Remember, the key here is to know what you're willing to pay for the lens, then the rest is easy:
  1. Go in knowing what lens you want and for what price.
  2. If possible, wait until the last minute to bid and bid the maximum amount you'd be willing to pay for that lens. This will prevent you from getting locked in to an auction and then seeing a better deal. It might also save you some money (by 'sniping'). If you can't be at the computer when the auction ends, just pop your maximum bid in earlier.
  3. Don't worry if you lose some auctions. You'd rather it take a little longer than regret a high price. Also, clumps of similar items selling at similar times seem to get the lowest prices.
  4. Consider insurance and tracking. If possible, insure the lens and get a tracking number. For cheap lenses, don't bother, most carriers offer $50 of insurance anyway. Anything over $100 I'd recommend insuring for sure and get a tracking number. This protects you and your new investment.
  5. When you win, pay immediately. The last thing you want to do is risk losing the item.
  6. DON'T LEAVE FEEDBACK YET! Wait until you receive the item and check it out. More on that in a little bit.

After You Win:

Assuming you won, insured, and added tracking to your lens, now you wait. And wait. And wait. Again, don't leave feedback yet!

eBay is a very buyer-centric auction environment. After all, the seller gets the money before you even touch the lens. The possibility of negative feedback is a powerful motivator and prevents many sellers from trying to do shady things (read Freakonomics; about 10% of the population will cheat regularly if given the opportunity). If you give positive feedback immediately, suddenly the seller has no motivation to get your item out the door and could even try to not ship it at all or replace it with a defective item. If there is a problem, the motivation to fix it is also decreased. The more 100% positive feedback a seller has, the more motivation they have to keep it perfect!

Track the item, and if it doesn't arrive (or the tracking doesn't update beyond getting entered into the system) e-mail the seller. Do it both through eBay and their e-mail address (if you have it) -- these types of e-mails often get automatically culled out by SPAM filters and you want to make sure you aren't waiting for that reason. I've noticed that sellers are much more likely to respond to a question if it is sent through the eBay system, but not always. Don't be afraid to send more than one note (not on the same day though, that's just rude).

With luck, the item arrives, and you are almost done.

First, give the item and packaging a thorough inspection. Was the item packed well? Was there any damage to the package, the lens, or the material. If so, document it! Take a picture!

Then, get the lens out and before you put it on the camera, give it a thorough check-up. Some things to do:
  1. Check external condition. Are there any dings, scratches, dents, obviously displaced lens elements? Especially if they aren't noted in the original auction.
  2. Rotate anything that's supposed to rotate and check out the zoom, manual focus, aperture if it has one, etc. If anything binds, makes noise, or feels too lose, make a note of it.
  3. Check internal condition. Look through the lens, pointing at a bright light source, and look for dust, scratches, fungus, cracks, and/or fog. Rotate the zoom and focus wheels through their range of motion too (often oil leaks and fungus problems will start on the edges). You should see a perfectly uniform, clear, bright circle. Any spidery lines or blotches on the edges usually means fungus (or oil). Scratches on the front element aren't generally serious, but if they didn't mention them and they are obvious, that's an issue. Scratches on the rear element are more severe but rare. Make a note of everything!
  4. If mechanical operation seems good, slap it on the camera and try it out. Don't put it on your camera if you hear grinding or worse! Then, take a few shots with it, making sure it acts as you'd expect.
  5. Make sure there isn't excessive slop in the different barrels of the lens. Cheap lenses tend to have more slop than expensive ones, and all lenses have a little space to move between barrels. But if it can move a lot (more than the tiniest bit on good lenses), you've got a problem and it may have been damaged by a drop. Make sure the mount seats well and doesn't move.
  6. Use it for a few shoots spread over different days. This gives intermittent problems a chance to pop up while you still have a chance of getting some remuneration.
Once you've completely checked out the lens, contact the seller about any major things that weren't as listed. For example, fungus, cracks, serious scratches, excessive slop, basically anything that could hurt your resale value. If there are any problems, contact the seller immediately and ask for a remedy, be it a partial refund (for minor problems that hurt resale but you're willing to deal with them) to a full refund (for major damage). Keep in mind they might ask you to pay to ship it back to them, which may be a huge hassle for a cheap lens.

But, this is why you withheld positive feedback. The feedback gives you leverage to get them to remedy the situation. Be willing to compromise though with a fair solution.

And, once you are satisfied, leave positive feedback, and enjoy your new lens!

Originally, I was going to add some stories from my experience (nothing horrible) but I've run out of time and space. So much for a brief guide. I'll do a follow-up in a few days detailing my problem lens purchases.

I hope this helps. If you have any questions or want some advice, leave a comment!

Monday, February 4, 2008

Cycle 61 Photography: "... absolutely own it..."

Through the Bay Area Strobists Flickr group, I stumbled upon Cycle 61 Photography, a.k.a. Nick Davis. Nick is working on starting up a photography business, and while I think he's chosen one of the hardest tasks possible (supporting himself with photography in one of the most expensive cities in the world) I think he has the right idea.

From Nick's first page of business goals:

"... I don't want to be just another landscape photographer, another wedding or headshot or whatever guy. I'm willing to work through that, but I'm going to find a niche, dig it out with an axe, make it viable, and absolutely own it. I want everybody who shoots in my field to have the thought, nagging in the back of their mind, that if they do a kick-ass job then everybody will think they're copying Nick Davis."
As someone who flirted with starting a business a while ago I know a bit about what it takes to succeed in photography: a ton of effort and a way to distinguish yourself from all those other photographers. Not to say that I've succeeded in any way, but I've seen enough to know how much work is involved. Trying to be a photographer 'like everyone else' isn't going to cut it anymore, nor will depending on selling microstock. You have to offer your customers something they can't get from anywhere else, be it your vision, unique style, personal skills, or experience.

And you have to commit to the endeavor: part time photography will not make you a lot of money without building the business for years, which is ultimately why I abandoned my plans (because we need money NOW, not in three years). Or, maybe I should say I just put them on the shelf for a while...

So, I'll wish Nick luck and recommend that you check out his blog. He's got good stuff on there already and it will be interesting to see his business plans evolve.

(from Cycle 61 Photography, used with permission)

PS My favorite image on his site was at the top of his second goals post (I won't show it here because I don't have permission). It has excellent color and texture, and it made me think:

"What the hell is that there for? Nuts and bolts?
Oh, I get it!"

Sunday, February 3, 2008

Review: Lambency Flash Diffuser

Finally, the day has arrived for a review of the Lambency Flash Diffuser which I purchased at the beginning of January. I haven't had a lot of time to work with it, but I've got plenty of experience and information to share. I'm pretty proud of this post; to my knowledge this is the only independent review of the Lambency diffuser on the net.

And for under $20, this diffuser is a steal... literally. The idea was stolen from Gary Fong, and while I'm not proud of supporting such blatant product theft, the price is right. The purchase post talks a bit more about that. I do recommend purchasing Gary Fong's LightSphere if you are able: while I haven't tested it, I have to assume it is better made, will be delivered faster, and includes a how-to DVD (I think, I didn't see confirmation on some parts of the web site).

But, this review is about the Lambency flash diffuser, so lets get to it...

Ordering and Delivery:

As mentioned in the previous post, I purchased SKU 7385 from DealExtreme for $16.82 including shipping. Since DealExtreme ships from Hong Kong, my order on Jan 7th was finally delivered on February 1st, a full 25 days later. Obviously, if you need a diffuser in a hurry, don't go for something overseas... And you could get it to move faster, but the shipping would cost you more than the diffuser!

I've also noticed a lot of lambency diffusers floating around on eBay, ranging in cost from $13 and up (including shipping). I've put a small search box below so you can check current prices (mouse over the price to see the shipping cost):

Another thing which makes ordering challenging is getting the right size. It seems like each seller has a different sizing guide which makes it difficult to know exactly which one to get (especially since I have a Sunpak 383 which is rarely listed). It turns out the side of the box has a sizing guide, so if in doubt, cross reference this guide to the seller listing to verify the correct size.

Gotta love the "Minonlta" option...

Physical Characteristics:

The diffuser and two domes (white and gold) come wrapped in thin plastic bags inside the box shown at the top of this post. That's it, no instructions of any kind, nothing else.

The domes and diffuser came in excellent condition (as shown below with the white dome in place). The domes are hard plastic while the diffuser is a soft, rubbery vinyl.

I've got to warn you now, the vinyl STINKS. This, coming from the guy who couldn't smell his own stinky sneakers (moldy the recent rain) which his wife wouldn't let him keep in the house, means the smell is quite strong. At first, I couldn't quite place the smell, but my wife described it as body odor. Only after doing a bit of research on vinyl, did I remember what it reminds me of: shower curtains.

And it turns out that vinyl outgassing is indeed harmful. So, please, keep the lambency diffuser away from children and in an airtight bag when in the house. Hopefully it will lose the smell over time, but remember that manufacturers overseas aren't held to the same toxicity standards that American manufacturers are. Allowing your toddler to play with this diffuser could be fatal (probably not, but why risk it?).

The diffuser attaches to your flash via friction. The base of the flash has numerous fingers (ridges) which grip tightly on your flash head (assuming you have the right size). If you accidentally buy a diffuser that is too small, you could probably cut the fingers down to size. If you buy one too large, you'll most likely be out of luck.

Placed on the camera (as shown below), the diffuser plus flash makes a combination that's VERY tall. The diffuser itself is quite heavy and was able to push my Sunpak 383's head over when I tilted the camera forward (to chimp). The extra weight could conceivably snap your flash foot or bend your flash shoe if you aren't careful. In actual use, it was pretty stable, but a bit awkward. Make sure you firmly tighten the flash to the shoe to avoid the flash falling off while in use.


All along, my biggest question has been, "How does this flash modifier actually modify the light?" Once I got it in my hands, my first priority was to get an idea of the distribution of light leaving the unit, which is information I will now share with you, dear reader.

To map the light distribution, I made use of a bare white wall in my bedroom. The first step was to place the flash against the wall, pointing up, and fire it at 1/16th power. With my 20D set on manual at 1/250s, ISO 100, and f/8, I took a number of images of the light projected on to the wall with different variations of diffusers. Each image can be enlarged by clicking on it.

Vertical Light Distribution

As you can see, the bare flash produces a bright cone of light directly in front of the flash head (as expected). The diffuser with no cone constricts the light a bit, but does throw a little more light in all directions. And with the dome installed, two cones of light are created: one wide cone above the dome, and a lighter wide cone below the head. Note the band of darkness in the plane of the cone.

Also, comparing the white cone to the gold cone, there is only a change in light color, although the outside of the upwards cone is colored less gold than the inside. I don't expect this will be enough of a color difference to notice in practice.

Next, keeping the flash close to the wall (about a foot or two away), I tried the flash with and without the white dome:

Horizontal Light Distribution (Close Range)

In this specific case, since the flash was closer the highlights saturated the sensor so I dropped the exposure by one stop. You can see that the cone causes a significant drop in the exposure directly in front of the flash; this light is then reflected behind and around the diffuser. It isn't obvious from this image, but the resulting light is significantly more diffuse also.

Horizontal Light Distribution (Far Range)

Moving the light back from the wall by about 6 feet, the most interesting thing happens -- the bare flash and the diffuser without the cone produce a similar distribution of light yet the diffuser with the cone produces a much lower light output. The output from the cone is much more diffuse and much wider (notice the light reflected from the mirror). The end result is a much more diffuse spread of light around the room.

So, obviously, the dome is designed to throw light in all directions, not just up into the ceiling (when the diffuser is pointing up). Maybe the softness of light claim made by Fong is due to the increased number of angles that light is pumped into the scene, almost a bare-bulb effect, but with a little more control and more ceiling bounce. Obviously, this kind of light isn't useful for all situations, but it can be very useful in an indoor environment when you are shooting people.

Likewise, aiming the diffuser forward should give improved light compared to the bare flash because it will be approximately six times the area. I haven't tested this very much and more experimentation will be needed to determine when to face the diffuser up and when to face it forward. I expect a close ceiling means aim it up to get the bounce.

Also, this isn't usually mentioned, but I think the lambency flash diffuser would be great for off-camera macro lighting to give very soft light. I'll have to try that too...

Real-World Results:

I got the diffuser on Friday night and didn't have a chance to really use it until the family went bowling on Saturday afternoon. In some cases, the bowling alley is perfect for on-camera flash (horrible lighting, most of the time the bowlers are in a darker area than the pins, etc). As a result of my experience, I have a few observations:
  • It stays on really well (once you get it on). The initial fit is tight and tough to get on quickly, but once it's on, it stays on.
  • The unit is heavy; be careful of the diffuser pushing the flash head down and putting undo stress on your flash shoe.
  • The amber/gold dome is very useful when shooting people indoors. Otherwise, the lighting makes the skin a little too cold (or green). But warming it up with the amber dome works wonders.
  • In dynamic situations it is difficult to balance ambient and a manual flash. It was a heck of a lot easier to use my 20D's flash with E-TTL to let it set the flash balance automatically. But I'm a trooper, so I slapped the Sunpak 383 on the camera and stuck with it.
  • The gold/amber dome works better given the warmish/green ambient.
  • The unit is large enough to attract some attention :)
Really, I don't feel like I have enough experience with the thing to really compare it to other techniques. As mentioned, I had a lot of trouble getting the balance right with the motion going on. Paired with an E-TTL speedlite (or the equivalent through-the-lens system from another manufacturer), the Lambency diffuser can be a really effective way to improve the qu

Another thing I noticed was the distinct drop in light intensity in the plane of the dome. For instance, notice the drop in brightness near my son's head in the image below:

But I did get some good shots, here are a few:

Friday, February 1, 2008

Anna's Hummingbird: What a Difference a Turn Makes!

This is an Anna's Hummingbird (WhatBird page, Wikipedia page):

This is the same bird a few moments later when it turns toward me:

Pretty big change, huh?

I took the shots an hour or two before sunset with my Sigma 600mm f/8. I'm not wild about the shots (mainly because of the distracting background which was way too light) but the reach of the Sigma really helps get shots that I couldn't before. Interestingly enough, both shots are at the same exposure -- the bird's coat really reflects light drastically differently based on the angle. Click to see the images larger.

Random trivia: an Anna's Hummingbird's heart beats at 21 times a second!

As a bonus, here's another decent shot I got out back of a Savannah Sparrow (I believe). Click to see it larger!