Help, Choosing a lens for bellows work.
Mar 12, 2019 01:46:17 #
19104
Loc: Philadelphia
If you have the choice of two different lens, one a regular like a 50mm f2 or a 50mm enlarging lens. Which generally would be a better choice for use on abellows?
Second question. This may be obvious, but if u have two lenses, will the one with the better resolution make a better choice for macro.
Second question. This may be obvious, but if u have two lenses, will the one with the better resolution make a better choice for macro.
Mar 12, 2019 09:48:26 #
A 50mm f/2 seems like a pretty high end (sharp) lens. The enlarging lens is supposed to be very sharp but that may depend on the brand. The enlarging lens supposedly will have optics for a shallower depth of field with exceptional sharpness where it has focus. But again that can depend on the brand.
If this is for single shot pictures, where you want some depth of field, the regular 50mm seems best.
If this is for focus stacking the standard thing to do, with good reason, is to go with a enlarging lens since they are supposed to be very sharp where they are in focus. But I am not sure if that is necessarily true for your enlarging lens and may not be true in comparison to a high end camera 50mm.
If this is for single shot pictures, where you want some depth of field, the regular 50mm seems best.
If this is for focus stacking the standard thing to do, with good reason, is to go with a enlarging lens since they are supposed to be very sharp where they are in focus. But I am not sure if that is necessarily true for your enlarging lens and may not be true in comparison to a high end camera 50mm.
Mar 12, 2019 11:00:36 #
What Mark said.
Tell us more about the enlarging lens, brand, etc. and your goals.
Tell us more about the enlarging lens, brand, etc. and your goals.
Mar 13, 2019 11:30:39 #
I also agree that Mark is spot-on in his assessment of the two lenses. I have experimented with an assortment of lenses and objectives with some degree of success and a larger degree of no so good results. What I personally find important is how "flat" the lens will focus to produce the best edge to edge sharpness. Many choices are sharp in the center but tend to soften at the edges.
When focus stacking the camera (or subject) moves forward as the other remains still. The lens stays at its set aperture and magnification so you end up with a apparent closer view and then an apparent further view during the stacking session. The illusion is that the image is larger when the focus is close and the image is smaller when the focus is further away.
A lens with soft edges will tend to be less sharp throughout the image to some degree as a final result when all of the images are stacked into one. Hence, a flat or "Plan" lens is most often desired.
When focus stacking the camera (or subject) moves forward as the other remains still. The lens stays at its set aperture and magnification so you end up with a apparent closer view and then an apparent further view during the stacking session. The illusion is that the image is larger when the focus is close and the image is smaller when the focus is further away.
A lens with soft edges will tend to be less sharp throughout the image to some degree as a final result when all of the images are stacked into one. Hence, a flat or "Plan" lens is most often desired.
Mar 15, 2019 11:21:24 #
For either the 50mm f2 or the 50mm enlarger lens, you will need to reverse the lens to get best performance. The f2 lens is likely designed for a max magnification of perhaps 1:4, and closer than this to the front element will be outside its design window. By reversing the lens, you can get 4:1 magnification or higher with the lens being still within design.
Most enlarger lenses are designed for enlargements from 2:1 up to 20:1. But again, think about what "enlargement" means...the print is bigger than the negative. So to get macro magnification with best image quality, you must reverse the lens, and it will work from 2:1 up.
The enlarger lens will likely be a better choice since it was designed for printing from a flat negative to a flat print. The f2 lens is likely not optimized for flatness of field.
A good lens to start with is the Nikon 50mm f2.8. It's fairly cheap and easy to find, and gives good results from 2x to perhaps 4x or even higher. It will even give a good result at 1x but the region around 1x is often difficult for many lenses except standard macros, or duplication lenses designed for that range. I'd recommend buying a "N" version of the lens, not because it's better, but because it's easier to find the reverse adapter for. You'll need a M40.5 reverse adapter to attach to the filter threads.
Most enlarger lenses are designed for enlargements from 2:1 up to 20:1. But again, think about what "enlargement" means...the print is bigger than the negative. So to get macro magnification with best image quality, you must reverse the lens, and it will work from 2:1 up.
The enlarger lens will likely be a better choice since it was designed for printing from a flat negative to a flat print. The f2 lens is likely not optimized for flatness of field.
A good lens to start with is the Nikon 50mm f2.8. It's fairly cheap and easy to find, and gives good results from 2x to perhaps 4x or even higher. It will even give a good result at 1x but the region around 1x is often difficult for many lenses except standard macros, or duplication lenses designed for that range. I'd recommend buying a "N" version of the lens, not because it's better, but because it's easier to find the reverse adapter for. You'll need a M40.5 reverse adapter to attach to the filter threads.
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