CAT/Mirror lenses on a 40D

SkedAddled · Expire: 2021-08-12

I've long been curious about using catadioptric mirror lenses, but have
a few questions for you fine people. I like the idea of such a compact
500mm or longer lens, easy to carry around.

First, I'm afraid that many CAT lenses won't clear the popup flash
assembly of my Canon EOS 40D. The lens bodies appear awfully close
to the mount end, making me think there's no clearance to mount
such a CAT lens. Am I wrong about this?

Second, I see lots of these CAT lenses with T2 ends, allowing whatever
T2-to-EOS mount I can find. What should I know about properly changing
such a T2 mount if it comes to this? What about infinity adjustment?

Third, what would your recommendations be for me to look for, as far as
relatively inexpensive but decent quality? I know that some of the Russian
mirrors are of high quality, as well as some of the third-party brandings,
but I really haven't been able to research it to satisfaction.

Thanks in advance for any pointers.

ManualFocus-G · Expire: 2014-11-24

Tamron SP 500/8 and 350/5.6 will be fine on the 40D. I believe some of the Russian ones will cause you problems though, for example the Rubinar 300/4.5 won't clear the flash. There's a guide somewhere on here showing how you can add a short extension stube and then adjust infinity I think.

Here's one:

http://www.rugift.com/photocameras/rubinar_lenses_with_various_cameras.htm

None of the lenses mentioned are small however, not long, but very wide!

RioRico · Posted: Tue Jul 20, 2010 1:01 pm Post subject:

I've a Pentax K20D with protruding flash housing, and I have two cats: a Korean-made Sakar 500/8 (420g, US$13) and a Russian-made Rubinar Makpo 1000/10 (1760g, US$225). The short (10cm long) 500/8's body diameter is 7.5cm, about the same as my DA18-250 walkaround, and is no problem at all.

The long 1000/10 (20cm + 8.5cm hood) is a different matter. I added 17mm of extension to the M39 mount, just enough so the 11.5cm-diameter body will clear the flash housing. I have NOT had to adjust infinity, but the extension changes the characteristics of the cat lens, increasing the f-stop and focal length slightly. This cat seems to have been designed to focus past infinity.

Both cats are flagged as 'macro' because their close focus is 1.5m. Both have excellent IQ when used correctly. The big gun is definitely not a walkaround; even on a tripod, I need sandbags for stabilization. The 500/8 (the sort you are considering) is quite easy to use. Its T2-PK adapter has needed no adjustment. As for quality... I can't advise you there.

Rusty · Posted: Tue Jul 20, 2010 2:32 pm Post subject:

Tokina 500mm /8 pk mount works great on my 50D with adapter no inf focus problems

ZeiEizh · Joined: 13 Jul 2010 Posts: 223 Location: Helsinki

MTO 500mm works fine with EOS adapter. Haven't check the flash though, because I may ever need that with 500mm which closest focusing distance is 4 metres.

SkedAddled · Expire: 2021-08-12

cooltouch · Joined: 15 Jan 2009 Posts: 9096 Location: Houston, Texas

I used a Sigma 600/8 mirror for years and have recently been seriously considering replacing it with another. I suspect you would have ample clearance for your 40D's pop-up flash.

Here's a pic of one mounted to a 20D:

SkedAddled · Expire: 2021-08-12

My thanks again for the knowledgeable replies.
I'm still figuring it out.

Would anyone consider US $300 too much to spend on a MTO 500
complete with all filters and original finger-jointed wooden case?
The lens appears to be pristine...

cooltouch · Joined: 15 Jan 2009 Posts: 9096 Location: Houston, Texas

You mean like this one?

Click here to see on Ebay

Dunno really. 20 years ago, the Russian mirrors could be had for pretty cheap. Nowadays it seems like they've been discovered, and go for a lot more.

Your original concerns about clearances, however, may be valid regarding that lens. Not much protrusion for the flange threads past the back face of the lens. MY Canon XS's pentaprism/flash housing overhangs the mount far enough (almost exactly 0.6" -- I just measured it) that I know it would have interference issues, even when taking the thickness of an EOS T-mount into account.