[Dubesor]

Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here.

---

I purchased a set of Asahi Bellowscope in M42 mount. It's a great vintage accessory, but it doesn't seem to work for my purposes. Maybe I'm just doing something wrong?

I was hoping to use it to block out side light and camera reflections when digitizing film (645 medium format film taped flat to a lightbox). I found that my camera and lens sometimes show up as reflections on the film "scans", especially in shadow areas on slides.

Anyway, with this bellows, I tried placing my Macro-Takumar 50mm lens on one end of it and my K-x DSLR on the other. But no matter what length I adjusted the bellows to - or what focusing distance I set on the lens - it was always way too close to the film and would fit 1/3rd of the area of the film negative at best.

I then tried mounting the lens directly on the camera again and placing the bellows in front. Of course that didn't work that well since the bellows has a 42mm diameter and the lens is 49mm, so it cuts off a big part of the field of view.

I wonder if extension rings would help my situation somehow? Or metal 49mm lens hoods if I could somehow stack a couple of them to get to 280mm length (that seems to be the minimum focusing distance with this lens that fits the whole piece of 645 film).

Or perhaps there's another type of bellows or some other light-tight attachment I can use? One that can screw in to 49mm filter thread on one end, have an opening big enough for 120 film on the other, and be adjustable to 280mm in length.

You can also read my older thread about this slide copy setup for background info.

---

Last edited by Dubesor; 03-14-2011 at 02:22 AM.

[Flickeroo]

Advice from a newbie, so i might be off track a bit because you might know more than i do:

Using the macro-takumar might give you too much magnification. 1:1 or 1:2 might just be too much.

I have used a bellows (the Pentax Auto-Bellows A with Slide attachment) to digitalize slides, and my best results were with either an M50 F1.7 and a Helios 58mm F2

I could theoretically have "zoomed out" more, but I didn't need to since it was 35mm film.

I didn't have a Takumar Macro, otherwise I would've tried it for sure. I just think that with the 1:1 or 1:2 Magnification ratio it might be too much for the size of your film.

Like I wrote before, I might be mistaken. If you have a normal, non-macro prime lying around I'd try it and see what the results are. Or just for fun, your Auto-Tak 35. You might have some distortion, but maybe not that much.


Flickeroo.

[Dubesor]

That's a good idea. And to think I just sold my last copy of the M 50/1.7 earlier this week. I thought I was holding onto it only for sentimental reasons (was the first lens I'd used when teaching myself photography in the early days). Luckily, I still have about five other 50mm to 55mm range primes I can try for this, and that 35mm you mentioned

[Lowell Goudge]

A bellows is not the best option for digitizing larger format prints since it is generally intended to produce high magnification which you don't need. Extension tubes will be no different since they are really only a solid bellows

Consider the format you are copying. 6 x 5.4 cm
Now consider the format you are copying to 2.4 x 1.6 cm

You only need 1/4 life-size

If copying to a dslr any lens in the 50 mm range should work, a macro lens is better because it is a flat field lens and you need to also consider just constructing your own shade to keep unwanted light out

[Dubesor]

A bellows is not the best option for digitizing larger format prints since it is generally intended to produce high magnification which you don't need. Extension tubes will be no different since they are really only a solid bellows

Consider the format you are copying. 6 x 5.4 cm
Now consider the format you are copying to 2.4 x 1.6 cm

You only need 1/4 life-size

If copying to a dslr any lens in the 50 mm range should work, a macro lens is better because it is a flat field lens and you need to also consider just constructing your own shade to keep unwanted light out

Yes, I was a little challenged figuring out exactly what I need. I guess I need to start hunting for a few long 49mm metal hoods to stack together. Or build my own 'hood' out of cardboard painted black ...

[Lowell Goudge]

Use black construction paper

Metal hoods will at some point vignette unless they get out to about 75mm diameter

[newarts]

.....Or perhaps there's another type of bellows or some other light-tight attachment I can use? One that can screw in to 49mm filter thread on one end, have an opening big enough for 120 film on the other, and be adjustable to 280mm in length.

Like Lowell said, all you need is something small enough for your lens on one end (49mm)and large enough for the MF film (85mm) on the other end, 280mm long.

Make it from a paperboard oatmeal box box painted black; glue a 49mm filter ring to the center of an oatmeal box' bottom and cut a hole for the lens to look through; paint it black Oatmeal is cheap - just buy a box of it; eat it or discard it.

Or stack some commercial hoods to reach the length and diameter you need. A good ebay vendor has what you need: Sonia cylindrical lens hoods, 86mm diameter, 73mm long, $12.95 delivered. 4 of theses can be stacked to reach 292 mm(they appear to have standard filter threads at the open end.) Step-up rings from 49mm to 86mm will also be required. This vendor also has such rings. The total cost should be around $75 USD I'd guess (I haven't priced the step-up rings.) Of course you could stack a series of increasing diameters to make a stepped conical hood...that would be nice looking and weigh a little less. It'd likely cost the same or a little less.

Sonia Metal 86mm 86 Tele Telephoto Lens Hood Shade NEW - eBay (item 370291671615 end time Apr-09-11 23:43:34 PDT)

[Dubesor]

Like Lowell said, all you need is something small enough for your lens on one end (49mm)and large enough for the MF film (85mm) on the other end, 280mm long.

Make it from a paperboard oatmeal box box painted black; glue a 49mm filter ring to the center of an oatmeal box' bottom and cut a hole for the lens to look through; paint it black Oatmeal is cheap - just buy a box of it; eat it or discard it.

Or stack some commercial hoods to reach the length and diameter you need. A good ebay vendor has what you need: Sonia cylindrical lens hoods, 86mm diameter, 73mm long, $12.95 delivered. 4 of theses can be stacked to reach 292 mm(they appear to have standard filter threads at the open end.) Step-up rings from 49mm to 86mm will also be required. This vendor also has such rings. The total cost should be around $75 USD I'd guess (I haven't priced the step-up rings.) Of course you could stack a series of increasing diameters to make a stepped conical hood...that would be nice looking and weigh a little less. It'd likely cost the same or a little less.

Sonia Metal 86mm 86 Tele Telephoto Lens Hood Shade NEW - eBay (item 370291671615 end time Apr-09-11 23:43:34 PDT)

That's good advice

So far today, I tried cutting holes for the macro lens and film in a brown paper container from coffee beans and a 1L Tetra-Pak milk container. Neither of these proved rigid enough or dark enough inside. Building my own tougher box or looking for a firm product box that has a bottom of similar dimensions to the 645 frame is the next step.

[newarts]

That's good advice

So far today, I tried cutting holes for the macro lens and film in a brown paper container from coffee beans and a 1L Tetra-Pak milk container. Neither of these proved rigid enough or dark enough inside. Building my own tougher box or looking for a firm product box that has a bottom of similar dimensions to the 645 frame is the next step.

"Quaker Instant Oatmeal". Flat black paint. Nuff said...

[Dubesor]

"Quaker Instant Oatmeal". Flat black paint. Nuff said...

I'll pick one up, lol. Also just spray painted inside of above-mentioned TetraPak matte black, maybe that'll work after all.

[pacerr]

"Quaker Instant Oatmeal". Flat black paint. Nuff said...

I'm proud o' ya, Dave!! Couldn't a said it better m'self.

I'll pick one up...

You might want to consider that the shade/hood doesn't have to be attached to the camera. It could just be a "tunnel" attached to/in front of the object you're shootin' - the camera sets inside the shade.

A flat black cardboard box sturdily tape-hinged on one side with the slide holder taped/attached to a window pointed toward a bright 'north sky' window? Custom WB. Certainly be a lot easier to handle that way.

H2

[Lowell Goudge]

Just a simple question, but what side are you photographing the emulsion side or the film side? The emulsion side is a lot less reflective

[Dubesor]

Just a simple question, but what side are you photographing the emulsion side or the film side? The emulsion side is a lot less reflective

I've been photographing the film side, the one that has the P645N data imprint, the correctly oriented image, and film stock info. I figured that was best since that's the side of the film that my film scanner scanned ...

Maybe I should try shooting the emulsion side and flipping horizontally in processing. But wouldn't I lose detail this way?