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 Replies: 7 / Views: 2,097 |
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Valued Member
United States
441 Posts |
I had read about the subject lens on another forum and wanted to try it out. Picked up one from ebay...not an El Cheapo lens as it was $99 shipped from Japan. I took three shots on a junk LMC just to see what it would do. Pics are below. I'd like the photography experts here to evaluate and tell me what they see as far as the physics of the lens...distortion, etc. I can't see much difference in pics. They look comparable to the SK Componon-S f4 80mm and Rodagon f4 80mm I've used. Used a Canon 1000d on Ray's Setup with a Pentax auto bellows. Working distance from coin to front of lens was about 8". No post processing at all on jpg except to crop and resize for posting. Any info/advice is appreciated. At f5.6 At f8 At f11 |
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Pillar of the Community
Canada
2784 Posts |
andy that is a very good lens. great pictures well done
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Valued Member
 United States
441 Posts |
Thank you Rocky. I value your opinion since you do post a lot of great pics here yourself.
In the above pictures, do you see any difference in the three given that they are taken at different f stops?
In your opinion, which one do you think came out the best?
Edited by andywoj00
06/24/2016 8:34 pm
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Pillar of the Community
 United States
4038 Posts |
It's tougher to tell differences because you are publishing down-sized images. However, the f5.6 is clearly less sharp than the f8. The f8 and f11 are tough to distinguish due to the downsizing, though f11 shows just a bit more diffraction softening. Because the f5.6 is distinguishable even after downsizing, the lens for sure is not optimum at f5.6. Another aspect of this is the lens changes in focal length as you stop it down. The f5.6 has highest magnification, with f8 a little lower, and f11 a little lower. This is usually not a good sign. Overall the lens looks like it does a good job, but definitely shows imperfections.
Edited by rmpsrpms
06/24/2016 9:46 pm
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Valued Member
United States
441 Posts |
Been playing with this lens a bit more. Not as crisp as a native macro lens would probably be, but I have to say that I'm pretty satisified with the results it gives. Only down side is that the working distance is so long. I will have to work on getting the focus just right.....somewhat more difficult than with my 75mm or 80mm lens'. Just snapped the ASE below. 12" from coin to front of lens. It's been post processed a bit. I may have to come up with a way to get the light diffuser that's on the lens a bit closer to the coin as well. Paper towel tube as an extension may work   |
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Pillar of the Community
United States
4038 Posts |
Nice images Andy. Was that at f8? Why do you want to change the lighting, it's excellent.
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Valued Member
United States
441 Posts |
Ray, Yes, f8. As far as the lighting, I thought I could do a bit better, but based on your feedback, I'll run with it for this particular set of coins ( ASE). From your earlier post you said " Another aspect of this is the lens changes in focal length as you stop it down. The f5.6 has highest magnification, with f8 a little lower, and f11 a little lower. This is usually not a good sign. " Can you expound on this a bit more ...stopping down relevant to focal length change and clarity? Why is this not a good sign? Andy |
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Pillar of the Community
United States
4038 Posts |
As you stop-down the lens, light passes through smaller and smaller area near the center of the lens. If the focal length changes, it means the lens manufacturing is a bit "off" in terms of the radii of the lens elements or the various lens spacings. The center of the lens has a different focal length than the middle, which is different from the edges. This will make light from different radii of the lens focus at different planes, and make the lens less sharp than it would be if the entire lens had the same focal length.
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Replies: 7 / Views: 2,097 |
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Posted 06/24/2016 8:33 pm
