Can a 100mm bellows lens achieve 1:1 slide duplication on a Minolta Auto Bellows I?
Asked 12/5/2018
2 views
2 answers
0
I'm trying to duplicate 35mm slides at 1:1 using a Sony A7R III, a Minolta Auto Bellows I, focusing rail, slide duplicator attachment, and a Minolta 100mm bellows lens that only has aperture control. I can't seem to reach focus within the bellows/rail travel. The closest workable focus I can get is with the slide roughly 400mm from the film plane, which is far beyond the slide duplicator's range.
I expected that extending the bellows would let me focus closer, but no combination of bellows extension and rail position seems to bring a slide into focus at the needed distance. Is this setup supposed to work for 1:1 with a 100mm lens, or is the lens simply the wrong focal length for this bellows and duplicator arrangement?
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
7y ago
2 Answers
3
Can any give me a good explanation of how this is supposed to work, or if it can work at all with a 100mm lens?
If you're set on using a 100mm lens, you will need to add some more distance between the camera and bellows, using extension tubes.
For 1:1 slide copy work, that bellows was intended to be used with a 50mm lens (or similar focal length). According to Rokkorfiles.com, the Auto Bellows 1 can achieve 0.7–3.0 magnification with a 50mm lens.
I use a Nikon PB-4 bellows (which is very similar to the Minolta Auto Bellows 1) with my full frame body with a 55mm ƒ/3.5 Micro to do my slide copying. The lens is quite sharp and has almost no field curvature (important for slide reproduction), and importantly, can be had easily for under $150.
Originally by user11924. Source · Licensed CC BY-SA 4.0
user11924
7y ago
0
Generated from our catalog & community — verify before relying on it.
A 100mm lens is likely the wrong choice for 1:1 slide copying on that bellows setup.
At 1:1, a simple lens needs about 2× its focal length from lens to sensor and about 2× its focal length from lens to subject. For a 100mm lens, that means roughly 200mm from lens to sensor and 200mm from lens to slide, so the total subject-to-sensor distance ends up around 400mm. That matches the distance where you found focus.
So the issue is not your technique; it’s that the Minolta Bellows I + slide duplicator was intended more for shorter lenses. A 50mm lens is the typical choice for 1:1 copying on this kind of bellows, and a 55mm macro is also commonly used. Those lenses give the necessary magnification with much more practical extension and working distance.
If you insist on using the 100mm lens, you would need additional extension between camera and bellows, such as extension tubes. For best slide-copy results, use a flat-field macro lens around 50–55mm.
Recommended products
UniqueBot
AI7y ago
Your Answer
Related Questions
Does a front-mounted close-up lens change bellows factor?
Can I copy 35mm slides with a Nikon 50mm f/1.8 instead of a macro lens?
Why are the edges blurry when digitizing slides with a slide duplicator and a macro lens?
Can a DSLR be used with a Minolta Auto Bellows I?
What camera rail or bellows setup can provide tilt, shift, and macro-to-infinity focus for a custom medium-format build?