mirror telephotos-good buy?

As someone who just recently got back in to photography. I have a

question about tele lenses. I have seen lenses on ebay for my camera

(T70) that are a mirror telephoto. I remember the old cassegrain type

telescope that were of very good quality. Now I know that based a

manufactor that quality can be good or bad. However in general are

these lenses a good buy for the money ($100-150)

 

 

Gary Griffin

Try a search on "mirror lens" in the photo.net archive, and you'll turn up a good amount of discussion on this issue.

 

Advantages: light weight, compact design, inherently apochromatic, low cost.

 

Disadvantages: fixed aperture, light loss due to inefficiency of the mirrors, low contrast, "donut" patterns of out of focus highlights (which may be distracting or may be used in a creative way), double-line patterns of straight lines in the out of focus area (which are almost always distracting, so you need to pay attention to the background), and generally they're just not as sharp as (much more expensive) refracting lenses.

 

I went through a 500mm and 1000mm mirror lens stage until I could afford something better. They worked for some subjects, and it sure was convenient to be able to put the relatively tiny Soligor 500/8.0 C/D lens in a jacket pocket on the off chance I might need a long lens, but I'm getting much better pictures now with my FD 400/4.5 and FD 600/4.5.

 

If you want to experiment with a mirror lens and maybe upgrade in the future, better quality mirror lenses that will hold their value are the original Canon FD 500mm/f:8 mirror lens, and the Vivitar Series 1 Solid Cat lenses, which use the T-mount system (be sure to get the "Solid Cat" version, as marked on the front of the lens).

Hi - I have a 500/8 Tokina mirror (cost $45). Not a bad lens if you understand it's limitations I guess. It is difficult to focus - and the moon is still this side of infinity! The aperture is not "really" f8 on my T90 - f9.5+ exposes better. Contrast is a bit washed out and you need to use fast film - 400 is good, 100 is a lesson in frustration.

 

The results are surprisingly sharp, in general, and itallows you to "reach out" using a very compact little lens! Try and pack a 500/5.6 in your vest pocket! It is also easy to spot the use of a mirror lens, although the little rings are not always distracting.

Saw the Canon 500 f8 in a shop. It was huge compared to other mirror lenses I have seen. Specifications are listed on http://www.canon.com/camera-museum/camera/lens/f_lens.html and show 90mm wide, by 146mm long. Of course this bulk is mostly air and it weighs in at a very portable 705g. While this is much smaller than the a 500mm refracting lens, it is not exactly pocket size. I wanted something compact for hiking so I did not buy it.

 

If you get one try to get the original case with it. All that space inside makes them more delicate (glass adds structure to a lens). I would check any potential purchase very carefully.

 

It has been mentioned that the Tokina 500 f8 actually behaves as f9.5 on the camera. There is a difference between the theoretical f value given by physics and practical f value that results from engineering. Some manufactures list the theoretical value on the lens. If you pay a premium for f5.6 you may find out it is really f8.

 

The two great advantages of a reflex design are weight and price. The drawbacks are given in earlier responses. If you will be walking a long way to get your shots then the lighter construction of the reflex lens means you can use a lighter tripod. In effect you get a double weight bonus!!!

 

As a thought....The Canon refractive lens at this length is the 500 F4.5L and it is not exactly cheap (http://mywebpages.comcast.net/starka/CanonFD_ebay2.htm give a rough estimate of relative pricing). There was an FL 500 f5.6 which may be cheaper.

 

One possibility would be to get something like the FD 300 F4SSC and use the Extender 1.4X-A. This would give you an effective 420 F5.6. The question is whether the drawbacks of the 1.4X converter are worse than the drawbacks on the 500 reflex. This combination costs roughly 50% more than the Canon reflex, but gives you a very good 300 f4 and a slightly compromised 420 f5.6. Of course this is a lot more expensive that the $100-150 you originally mentioned.

I often use the FD 400/4.5 S.S.C. with a 1.4X-A and the results are unquestionably better than with a mirror lens.

 

(For those who know the 400/4.5 S.S.C. and the 1.4X and wonder how this is possible--because there is a mask near the lens mount that obstructs the protruding elements of the 1.4X-A--I very carefully filed out the mask so the extender would fit. You could also have it enlarged by a machinist. This is not a problem on later versions of the FD 400/4.5)

Thanks for all the positive responses I believe that I will purchase one of these and learn.