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01-25-2017, 05:52 AM   #1
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Auto Bellows - which macro lens - Takumar Bellows 100 or "normal" Takumar Macro 100?

I have an auto bellows unit with slide attachment I'm using with a K3 II, and I am planning on converting slides to digital and delving into general macro photography. I'm trying to decide if I want to get one of the Takumar Bellows 100 macro lenses without any focus adjustment or an M42 mount SMC Takumar Macro 100 that has focus adjustment. I guess I'm really wondering if there is any down side to the full blown lens with focus adjustment on the bellows unit versus the specific bellows lens? I'm under the impression they are the same optically. Will I run into issues where the lens with focus adjustment is too long? I like the idea I could use the general lens on the camera for generic macro work without the bellows. I do plan on buying a modern D FA 100/2.8 at some point, so I know at that time the screw mount macro lens would become less attractive on my K3 II. Thoughts from real life experience?

Thanks in advance.

01-25-2017, 07:12 AM   #2
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I don't think you will be able to focus at all on the slide using a 100mm lens. The rail is not long enough, even with a full frame sensor. And using a 50-55mm will not allow you to capture the entire slide frame either for the same reason.

In my Auto Bellows-A manual the working distance with 100mm Bellows Macro for 1 magnification is 190mm at an extension of 138mm. So you would need 190mm between the front of the lens and the slide. The same working distance is given for the M-Macro 100mm at 100mm of extension.

There are posts on the forum on workarounds.
01-25-2017, 08:04 AM   #3
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I've experimented with multiple lenses with bellows and K3. It is absolutely NOT POSSIBLE to copy an entire 35mm slide with any lens, you will always get a crop. FYI I tried 100mm bellows, 70mm f2.4, 50mm, 40mm, 35mm and 50mm enlarging lens in both normal and reversed orientation. None of these would cover an entire 35mm chrome on an APS-C sensor using the slide-copy attachment mechanism of a Pentax bellows. You'd have to place the slide on a light box and use a copy stand.
01-25-2017, 09:26 AM   #4
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I put together a rig that looks something like this one I found online:"Scanning" negatives with a Pentax DSLR - Photo.net Pentax Forum

I used a 50mm Macro Takumar (which gives 1:2 on its own) and an extension tube to bring it the degree of magnification (more than 1:2, less than 1:1) for the 35mm slide to fill the APS-C sensor. I think I used about 25mm of extension (I'm at work, my stuff's at home, so I can't check right now). I used the slide duplicator part of my bellows, replacing the metal rod with a piece of dowel attached to what had once been an accessory bracket. The bracket was screwed into the tripod socket on the bottom of my camera. I used a slaved off camera flash set to low power manual discharge (1/128?) triggered by my K-S2's built-in flash (also set to 1/128, to conserve power). Kind of a kluge, but it worked well enough for what I needed to do.

01-25-2017, 10:10 AM   #5
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One problem you can run into by extending the rail is the bellows between the slide copier and lens may not be long enough. You risk tearing the material if you stretch it too far.
01-25-2017, 11:01 AM   #6
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Thanks for the replies - this is making more sense. I have 35, 50, and 55mm Takumar lenses on hand and was able to get almost all of a slide in the frame with the 55 - close enough I could live with it for most shots. It was just a tiny loss on one edge. I was thinking with the 100 bellows lens I'd get the whole thing in. Am I off on that? Regardless, it sounds like I should look for a bellows 100 versus a full size lens for work any work with the bellows and that focal length.
01-25-2017, 11:06 AM   #7
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QuoteOriginally posted by clickclick Quote
Thanks for the replies - this is making more sense. I have 35, 50, and 55mm Takumar lenses on hand and was able to get almost all of a slide in the frame with the 55 - close enough I could live with it for most shots. It was just a tiny loss on one edge. I was thinking with the 100 bellows lens I'd get the whole thing in. Am I off on that? Regardless, it sounds like I should look for a bellows 100 versus a full size lens for work any work with the bellows and that focal length.

No. With the 100 set at about 1.5:1, which is what you need to copy all of a 35mm slide to an ASP-C sensor, the distance from lens to slide will be far too great for the slide copy bellows attachment. I tried, and the devise cannot be extended any where near far enough. In fact, I was unable to obtain focus on a slide mounted in the device at any reproduction ratio using the 100mm bellows lens.
01-25-2017, 12:12 PM   #8
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QuoteOriginally posted by WPRESTO Quote
No. With the 100 set at about 1.5:1, which is what you need to copy all of a 35mm slide to an ASP-C sensor, the distance from lens to slide will be far too great for the slide copy bellows attachment. I tried, and the devise cannot be extended any where near far enough. In fact, I was unable to obtain focus on a slide mounted in the device at any reproduction ratio using the 100mm bellows lens.

cool - thank you! Now I can move forward and will know what to expect. Sounds like unless I want to rig up an extension for bellows and rack, I am best with the 55 Takumar and a tiny crop on one edge. I must say I wouldn't want to stretch the bellows any further. I was just able to get it very close last night and was thinking I would not want to put any more stress on the bellows itself.

01-25-2017, 01:04 PM   #9
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Yes. I decided, as noted, I would have to put the slide onto a light box or somehow light it from the rear without the bellows at all, just using a good quality macro. However, now I have a K1, so I can try the bellows mechanism on that. BTW, one tricky part of slide duplication is avoiding a central hot spot, or IOW, getting corner-to-edge-to-center uniform lighting. An inevitable annoyance is spotting out all the dust specks.
01-25-2017, 01:17 PM   #10
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QuoteOriginally posted by WPRESTO Quote
BTW, one tricky part of slide duplication is avoiding a central hot spot, or IOW, getting corner-to-edge-to-center uniform lighting. An inevitable annoyance is spotting out all the dust specks.
Another annoyance is that cardboard mount slides will often bulge in the center making it difficult keep the center and corners in-focus. A non-flat field lens (most non-macro) lens may even be to your advantage when this happens. Remounting the slides into glass mounts is one solution, although Newton rings may then become a problem.
01-25-2017, 01:27 PM   #11
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QuoteOriginally posted by Not a Number Quote
Another annoyance is that cardboard mount slides will often bulge in the center making it difficult keep the center and corners in-focus. A non-flat field lens (most non-macro) lens may even be to your advantage when this happens. Remounting the slides into glass mounts is one solution, although Newton rings may then become a problem.

And also if you sandwich between two glass sheets, that's four more surfaces that will carry along some dust. I have quite a few of my best chromes in Gepe glass mounts because that makes them almost jam-proof in a slide tray.
01-25-2017, 04:55 PM   #12
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I was having good luck on lighting with the white diffuser in place on the slide copier and then a 120 LED light with it's own diffuser set back a ways. I'm amazed at the dust that was revealed. It makes me want to wash them, but then the mounts will surely be a mess. I've got a bag of decent plastic mounts around here, but remounting wasn't really on my work flow - plus, I'd like to shoot some slide film and use them on new stuff. I was also looking at this wondering if the slides would be held uniformly enough and would there be enough depth of field to get away without refocising each slide and do some mass production. I've got a feeling that's not the case and this is going to become a cottage industry, and I'll be focusing a lot. Wish the eyes worked like they did 20 years ago....
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