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 Replies: 21 / Views: 4,094 |
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Pillar of the Community
 United States
4038 Posts |
Andy...unfortunately it won't work on bellows, only extensions. Bellows minimum extension is too long, so the lowest magnification you can get is already too high for whole sets. Only way you can get it to work is on the <$400 setup with minimal extension. Canon cameras already have 44mm extension from the sensor to the lens mounting plane (the "register distance") so with a 50mm lens you can only tolerate a few more mm to frame whole sets. I don't remember how big sets are, but let's say they are 4"x6". The sensor is 15mm high, so the magnification would have to be 15mm/4" (15mm/100mm) or 0.15. Then the extension would be 50 + 0.15*50 = 57.5mm. Subtracting the 44mm register distance, this gives an extension of 13.5mm. The exact extension is dependent on the lens, since the formulas assume the lens has zero thickness. So it's possible only an adapter plus a 7mm extension or so would be needed to achieve the right magnification, but this must be experimented with to get it right. From this calculation you can see that for sure the bellows is going to be too long...Ray
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Valued Member
United States
441 Posts |
So can the camera be mounted direct to the focus rail bar, with the enlarger lens mounted direct on the camera and still be able to frame/focus the whole mint set? Or is it dependent on the physics of the particular lens being used? I may have to take stuff apart to experiment.
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New Member
 United States
22 Posts |
Thanks Ray
I ordered the lens will get some pictures up when it arrives.
Thanking everyone for their help/tips
Sean
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Valued Member
United States
441 Posts |
Ray/dsmcnair, I took some more pics using the aforementioned prime lens I have. Sadly, I can find no way to use my enlarger lenses with my A-Stand setup. I tried only mounting a helicoil with the enlarger len to my T6i so my extension would be minimal....no matter what distance I set or lens I used, I could not get the full sets in frame/focus. Tried 35mm, 50mm, 80mm, and 105mm enlarger lenses..nothing worked. What am I doing wrong  FYI, the distance from the back of the helicoil to the front of the Omegar 50mm lens is ~41mm.I was able to figure out a pretty good lighting scheme with the older proof set to eliminate glare/reflections. However, the newer, larger sets are a different story. The newer coins are mega-shiney and it's difficult to light directly or diffuse without glare/reflections. I reflected two lights off the ceiling along with mounting a piece of black construction paper to the lens to eliminate the glare/reflections. See results below. I may need to experiment more with a different way on the new sets...not real pleased with this result. Minimal post processing. If anyone has a good way to pic the newer sets, please post. Pics of lighting and camera setups would be great. dsmcnair...if you come up with a way to get good shots with the A-stand setup and enlarger lens, please share. I can't get it to work.   Edited by andywoj00
10/22/2016 5:14 pm
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Pillar of the Community
United States
4038 Posts |
Quote:
I took some more pics using the aforementioned prime lens I have. Sadly, I can find no way to use my enlarger lenses with my A-Stand setup. I tried only mounting a helicoil with the enlarger len to my T6i so my extension would be minimal....no matter what distance I set or lens I used, I could not get the full sets in frame/focus. Tried 35mm, 50mm, 80mm, and 105mm enlarger lenses..nothing worked. What am I doing wrong
FYI, the distance from the back of the helicoil to the front of the Omegar 50mm lens is ~41mm. Well, from my earlier calculations, the max extension you can tolerate is 13.5mm. This may mean the lens must be mounted directly to the camera adapter, but it may allow some small (7mm?) extension. Will need to be experimented with. Definitely the helicoid is going to be too long. Its minimum extension is 17mm, plus adapter. So with 50mm lens, magnification will be too high for the sets. With 75mm lens, even at max extension, the magnification will be too low (!!). Tricky business this. Edited by rmpsrpms
10/22/2016 5:49 pm
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Pillar of the Community
United States
4038 Posts |
I just checked with the 50mm EL-Nikkor, and it works well. I used a EOS-M42 adapter, a 7mm extension, then a helicoil type M39-M42 adapter on the lens. These are all items recommended in the <$400 setup. Mint sets are 3-1/2"x5-1/4", and the field of view with the 7mm extension is about 3-3/4"x5-1/2", so fits nicely.
Contact me for photographic equipment or visit my home page at: http://macrocoins.com |
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Valued Member
United States
441 Posts |
Ray, Are you talking about the parts as shown and assembled below? I mounted to the camera and cannot get anything to come into focus. What am I doing incorrectly?   Edited by andywoj00
10/22/2016 9:51 pm
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Pillar of the Community
United States
4038 Posts |
Andy...your extension is too long! Don't install the helicoid....Ray
Contact me for photographic equipment or visit my home page at: http://macrocoins.com |
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Pillar of the Community
United States
4038 Posts |
Andy...maybe the confusion is between "helicoid" and "helicoil". They are different things...Ray
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Valued Member
United States
441 Posts |
Ray,
I think I figured it out. The 50mm lens I'm using just won't work with this setup. Correct me if I'm wrong, but it's an enlarger lens vs a duplicating lens so it won't focus properly with the helicoil setup, right?
I put on a 75mm APO Rodagon D and was able to frame/focus the older proof set. However, I had to use a tripod and the distance from the end of the lens to the proof set was ~22".
Given that, what type of lens would I need to get in order to be able to use the A-stand setup? An El Nikkor in 35 to 50mm range?
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Valued Member
United States
441 Posts |
Quote:
Andy...maybe the confusion is between "helicoid" and "helicoil". They are different things...Ray Yep, I'm confused. What is a helicoil? Apparently, I don't have one relative to photography. The only helicoil I know is what's used to repair stripped out threads in an engine block.  Edited by andywoj00
10/22/2016 10:20 pm
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Pillar of the Community
United States
4038 Posts |
Quote:
I think I figured it out. The 50mm lens I'm using just won't work with this setup. Correct me if I'm wrong, but it's an enlarger lens vs a duplicating lens so it won't focus properly with the helicoil setup, right?
I put on a 75mm APO Rodagon D and was able to frame/focus the older proof set. However, I had to use a tripod and the distance from the end of the lens to the proof set was ~22".
Given that, what type of lens would I need to get in order to be able to use the A-stand setup? An El Nikkor in 35 to 50mm range? Your 50mm should work fine if you get the correct amount of extension. Quote:
Yep, I'm confused. What is a helicoil? Apparently, I don't have one relative to photography.
The only helicoil I know is what's used to repair stripped out threads in an engine block. That's correct, the type of adapter I recommended in the >$400 was just like the helicoil for stripped out threads. 39mm inside, 42mm outside. Contact me for photographic equipment or visit my home page at: http://macrocoins.com |
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New Member
United States
22 Posts |
Ray, Lens showed up today! NIKON EL-NIKKOR PHOTO ENLARGER LENS - 50MM 1:2.8 I have it attached to the XSi with just the 7mm extension and the lens. I can frame the mint set but without the helicoid cannot focus. My first shot with some glare two Jansco led lights with some diffuser on the light.  |
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Pillar of the Community
United States
4038 Posts |
You'll need to focus by moving the camera closer/farther from the mint set...Ray
Contact me for photographic equipment or visit my home page at: http://macrocoins.com |
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Pillar of the Community
United States
4038 Posts |
Hey dsmcnair, were you able to frame and shoot the mint set? Would like to hear about and see the results?
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Replies: 21 / Views: 4,094 |
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First Page
Posted 10/22/2016 12:21 am
