El-Cheapo Lenses

Ray, I've been looking for the the M39 to M42 adapter, I originally bought the 75mm El omegar and found it to be 39MM,

I have the canon adapter for the 42MM screw, will this work?
love to try it on the bellows. Gene

I picked up the adapter today, I've been wanting to try this lens out on my bellows...ThanksGene

Ray what is the thread size of the schnider lens?
the listings do not say anything of what you need to mount them, so I'm guessing M39?

Well, it wasn't dirt cheap ($39) but I just received a Tominon E36 86mm f/4 today. I'd like to hear from anyone who has info on these interesting little gems. They seem to be fairly apochromatic, and unlike many other Tominon's on the market which have Copal M40 threading the 86/4 has M39 threads. Interestingly, smallest aperture setting is f/8 so I'm assuming these were intended for relatively high resolution work. 86mm is a very nice focal length for bellows as well. Here is my reference 1957D Lincoln Cent Toner taken with this lens:

Before I answer the question, I have some background explanation...

This is a 4x-reduced image from the original 4928x3264 (Nikon D7000) to 1232x816, and then cropped to 800x800. The reduction process increases the apparent resolution of the final image and allows lower quality (and even high quality) lenses to look better.

Note however the entire coin looks sharp, not just the center, so this is a testament to the T86 flatness of field. The larger you make the image on the sensor, the more the lens aberrations and flatness of field come into play so even a 4x reduction can't produce a nice image when the lens doesn't focus well at the edges of the coin, or produces off-color.

This shot was taken at f/8. Notice the background is reasonably clear, which would not be the case at f4. This reduces aberrations and also helps with field flatness since any flatness issues are mitigated by the increased DOF of the smaller aperture.

The reason for stating the above is that in this situation (4x reduction and f/8 aperture) the difference between the Printing-Nikkor and the T86 is very small. Printing-Nikkor color may be a bit more accurate, but the T86 is actually quite good. I see no color fringing when focusing with the T86, so it is very well-corrected.

The difference between the lenses becomes apparent at smaller apertures, with no reduction. So for example, if I took the same image at f/4 with both lenses, and instead of reducing the images I looked at fine details on the coin such as the date and mintmark area, the Printing-Nikkor would be sharper than the T86. Also, if I critically-focused both of the lenses on the center of the coin (cheekbone) the Printing-Nikkor would be better focused and sharper on the rims of the coin than the T86. And finally note that the Printing-Nikkor can go to f/2.8, so resolution can be increased even further, though at that aperture you need to focus stack to get good sharpness in the final image. There are always tradeoffs!

You can see extensive test results for the 105PN on Mark Goodman's coinimaging.com website. He has been testing a lot of lenses and has a very methodical and of course numismatically-oriented approach. Here's the link:

http://coinimaging.com/Lens_tests.html

That brings me back to the whole point of this thread: you don't need to spend $2500 (or even $250) on a Macro lens for coin imaging for Web publishing...this $39 T86 lens can produce a remarkably-sharp image at the 800x800 image size that is standard for posts on this forum and many other similar lenses are available with excellent performance.

forgot, the adapters I first got were for the M39 to EOS, not a working item at this time, still waiting for the M39 to M42, slow boat from china, maybe next week sometime, and one other adapter for the bellows....or possibly the canon FD to EOS, From what I am seeing, many of these lenses need the use of a bellows, as being directly connected to the camera isn't working,

Thanks Ray for the tip, I got it and will get around for the adapter later as I'm in the middle of moving and remodeling..I did receive the M42 to EOS adapter today , I just took a couple of pics to see what my Asahi Super Takumar 1:1.8/55MM would do, the first shots didn't turn out as I think the lens was not parallel to the coin , figured this out after switching to almost infinity settings as taken here..I'm thinking on the large dollar the edgdes are not to crisp...I don't have the best eyes...I'll try later tonight to try the Marco settings, and try my cheapo Chinon 135MM as its a 42mm screw as well...

Ray, these were full shots with my 55MM Asahi attached to the EOS...with my new adapter cropped down.... Thanks for the tip on the Tominion, would like to find the 105MM of that series..
I bought another cheap lens, for $10bucks..a Vivitar 70-200MM macro zoom...Took some pics, and some with a 2X converter...




I am wondering, with coins does one need or use the filters that are on the front of the lenses when shooting coins?