Friday, January 11, 2008

Sigma 600mm f/8: An eBay 'Oops'

An eBay mistake can be a very expensive mistake. One bad click can... well, that's why they make you confirm your bid.

On the other hand, one impulse bid and... well, let's start from the beginning.


By the date marked on my draft containing my notes, I know I started looking on Tuesday. It'd been on my mind for a while before that, but Tuesday was when I got serious.

I wanted a longer lens to shoot images of birds with.

Of course, you know that. I've wanted a decent macro lens and a super telephoto beyond 300mm for a while. But after my last outing (note to self: some of the pictures from which still need to be posted), I'm really realizing that 200mm isn't going to cut it for any birds smaller than a chicken that aren't brain-damaged enough to let me get really close to them. So I need a longer lens to reach them.

The problem is, long telephotos contain a lot of glass. And those ground glass elements need to be high caliber. And lots of heavy, precision glass in a tube costs lots of money...

Money. That's my problem. I don't have enough of it.

Most lenses in the 400mm or longer range cost more than $1,000. Used. Hell, the majority of lenses longer than 400mm are $2,000+ since the shooters that need them are professional nature or sports photographers. For an amateur like me though, I'd ideally like something in the $200 range. And most telephotos in the $200 or below range are absolute crap.

But, common wisdom says there's got to be some good deals out there, so that's what I was on eBay doing. Looking for deals, researching old lenses in Google, and trying to figure out a way to get some extra reach for between $100 and $200. I've got lots of options to share with you, including some bargain (but good quality) lenses, teleconverters, and vintage equipment (and how to make it work) but I need to pace myself on those posts.

Because I already bought a lens today on eBay.


I was on my main eBay page, and I noticed that the Sigma 600mm f/8 I'd e-mailed the seller about was set to end in 2 minutes. And hey, she had one bid, at her (lowered) asking price of $69.99. So I clicked over to it.

Hmm... 1 minute, 25 seconds left. Why didn't I want this lens again? Isn't it a deal at this new price?

Reload the page; 45 seconds left. Maybe I should take a shot at it. It'd be a deal if I got it for $80, right?

Click the bid button, type in my password, type in $80. If I win it, it was meant to be. Submit.

"You are winning, but the auction isn't over yet!" it says. My bid is $78. 17 seconds left. Is the other guy going to snipe it from me? Wait, I think I want him to snipe it. Why didn't I want this lens again?

"Congratulations! You are the winning bidder!" It says.

, I say. What have I done?


Not all lenses work using refraction like a magnifying glass. In fact, many long focal length lenses, such as telescopes (both the intergalactic type on mountains and those for hobbyists), use mirrors to reflect the light and achieve high magnification without really large solid blocks of glass. The most common system used in camera lenses and telescopes is a catadioptric system which folds light back in to itself to achieve high magnification in a small, light package. Often, these lenses are referred to as mirror or reflex lenses, although they also have refractive lenses in them.

Reflex lenses are notorious for being cheap long telephotos with very limited performance. One big drawback is the donut-shaped bokeh which can be very distracting if you have bright highlights behind your subject. Another drawback is that they always have a fixed aperture, typically very slow, which is in direct conflict with the need for a high shutter speed for such a long focal length. Also, these lenses almost never have autofocus. Finally, while mirror lenses are typically cheaper, cheapness results in low quality optics.

Of those, the Sigma 600mm f/8 is one of the better lenses. There are definitely other, higher quality reflex lenses out there, most notably the solid-cat Vivitars (named for the solid glass instead of air inside the 'light-folding' area). But when I was looking around, the Sigma 600mm f/8 was always very well-respected... for a reflex lens. Mirror lenses have a bad name, especially for their slowness, and most reviews of them have been negative.

My sources on the subject:

In my research, there was one page that really convinced me that a reflex lens was not a good way to go:
  • comparison between Sigma 600mm w/ FD converter and a 200mm Canon lens. The review shows the Sigma 600mm w/ converter actually performing worse than an up sampled 200mm. Not at all what I expected.
Of course, I didn't remember all this stuff BEFORE I bid...


In true masochistic fashion, I decide to look at all the links above again AFTER I win the bid. When it is too late to change anything.

Essentially, the Sigma 600mm F/8 is one of the better mirror lenses, but most mirror lenses are so quirky and lacking in performance that everyone prefers refractive lenses. I did get the lens at the going rate of a little under $100 (it was a $300 lens new), although it appears my lens is an older version of the Sigma 600mm F/8. Hopefully that won't hurt me too much.

Oh, yeah, I forgot to mention something...

It is a Canon FD-mount lens.

I won't go into the details here, but the FD mount is what Canon totally scrapped when it switched to the EF/EOS mount. FD lenses, about 20 years old, can't be mounted on the new cameras and require an FD to EOS adapter (with optical component) to make them work. Without the optical component the adapter works as an extension tube, causing you to lose infinity focus... Hmm, when do we not care about autofocus and infinity focus, yet like extension tubes?

But I digress, that's another post for another day.

So I'll need to grab an FD to EOS adapter on eBay ($40 shipped). And even then, according to the comparison, it may not even perform better than upsampling images from my Canon 70-200mm F/4. In other words, it might be worth nothing to me and I'll have to turn around and sell it again on eBay. I'm hoping that part of the performance problem is from the lens in the converter -- I've heard rumors that most mirror lenses can focus past infinity, so maybe I can use the converter without the optical lens for my needs (some have removable lenses), and gain some quality.

But it's paid for and will be shipped out on Monday, so I guess we'll find out, won't we...

1 comment:

Anonymous said...

I also have this Sigma catadioptric lense w/30.5mm filter set. It performed quite well in its 35mm days (mostly feeding it 800-1000 iso). I have found that now (in the day of digital) it makes an excellent telescope, with its sizable 75mm objective, 600mm fl, and f/8. All you need is any 3mm to 25mm 1.25" eyepiece, or an old triplet jeweler's loupe at say 30x. Use an old plastic rear lense cap, cut a hole to mount a tube to mount & focus your occular (a kids mega-block works well ~ like big legos), and wah-lah, you can now enjoy Jupiter's bands/moons each clear night, and Plato's crater on the moon. You can easily push it over 150x. I'd call that pretty impressive optics for your $80. (Just in case your EOS adapter mount did not work out).