zm 5a 500mm catadioptric

<p>Hi to all, I would like to get your opinions about the zm5a (or 3m5a) 500mm f:8 Russian catadioptric lens for nature shots.<br>

Fernando</p>

<p>yes it is light and cheap<br />after those two points the good news end<br />you'b better go with some Tamron</p>

<p>two words, "doughnut bokeh"</p>

<p>The disturbing bokeh patterns, along with fixed aperatures limit the usefulness of cat lenses for any application.</p>

<p><Chas><br /><br /></p>

<p>I agree, the doughnut patterns are generally quite distracting. Also these lenses tend to have poor contrast (although I haven't used this lens myself). That all said I have seen a few good images taken with these lenses.</p>

<p>As is equally true with "regular" dioptric optics, some cats are really good while others are really not so good. The bokeh can be really ugly, but on the other hand it's not that difficult to learn how to avoid donuts by careful choice of POV or by application of various post processing tricks - see<a href="http://www.dyxum.com/dforum/avoiding-donuts-with-a-reflex-lens_topic101105.html"> here for a recent discussion</a> on the issue in dyxum.com viz the Sony/Minolta 500 f8 (one and only AF cat ever produced) and <a href="/photodb/folder?folder_id=807202">here in my portfolio</a> for examples shot with that particular lens, as well as others shot with the Tamron adaptall-2 500 f8.</p>

<p>The doughnut patterns are a matter of taste -- some people hate them, some don't care and there are ways to work around them. But CAT lenses have been used for decades by thousands of happy photographers. I've shot many good images with my Nikon 500.<br /><br />The Russian lenses have been made forever and were a temptation back when I didn't have a 500 at all. But given that you can get a used Nikon 500 (and I assume Canon and other brands have the same) pretty cheap these days, I would go with the camera-maker's brand. I find a 500 CAT easy to focus -- the image is either in focus or it isn't -- so the older manual focus lenses are a bargain.</p>

<p><strong><a href="/photodb/user?user_id=938526">Craig Shearman</a></strong>, yes the older lens like MTOs were built to survive a nuclear war<br />but the discussed one ЗМ5А was the newer one and a child of deeply rotten economy<br />so it is sometimes not well justified and prone to inner peel off etc.</p>

<p>the examples shown are good as cropped sensors help to use only a center of image and image fall off is not that bad for instance</p>

<p>the same applies to also real bad contrast problem</p>

<p>i had no Tamron nor Minolta 500/8 to study side by side<br />but stay away from this one if possible</p>

<p>I suspect that it won't be good. I've yet to test a Russian lens that I'd classify as good and I've yet to test a cheap 500mm lens that I'd classify as good, so it probably fails on both counts.</p>

<p>I'd look for a used Tamron 500/8 (see <a href="http://www.bobatkins.com/photography/tutorials/mirror.html">http://www.bobatkins.com/photography/tutorials/mirror.html</a>) if I really wanted a mirror lens and I had limited funds. You can often find them for a reasonable price on eBay</p>

<p>If you want to see a test of an inexpensive Korean 500mm f6.3 lens see <a href="http://www.bobatkins.com/photography/tutorials/mirror.html">http://www.bobatkins.com/photography/tutorials/mirror.html</a>. I have some comparison shots of the Tamron and the Pro-Optics 500mm mirror lenses there.</p>

<p>Just a correction to your second link Bob, the f6.3 is at <a href="http://www.bobatkins.com/photography/reviews/pro_optic_500_f6-3.html">http://www.bobatkins.com/photography/reviews/pro_optic_500_f6-3.html </a></p>