Rolleiflex 3003 Polaroid Back Observation...

[ic-racer]

I got a Rolleiflex 3003 Polaroid back and it looks like it was made with a glass slab rather than a light pipe. It obviously makes out-of-focus images on the Polaroid film.
I wonder if the Rolleiflex 3003 backs were all made that way? Did Marty Forscher have the only stash of inexpensive light-pipe panels?

The things that make me think the glass might be original are as follows:

1) Protector reads "Supersensitive plate of glass"
2) The glass plate is precision cut and has a precision machined bevel around the edge
3) The glass plate is coated on both sides! This is not a scrap of glass from a frame shop.
4) No where in Rolleiflex literature on the product does it indicate the unit is manufactured with a light-pipe panel. The Rolleiflex 3003 system catalog reads: "Optical compensation for the longer film distance in the Polaroid magazine is achieved by means of a flat parallel glass plate." This is in strong contrast to NPC's literature which claims "Fused coherent fiber optic element. 11 micron fiber size; 21 million fibers."
5) I have not found internet pictures or e-bay pictues of the Marty Forscher Light-pipe backs with chips or cracks.
6) The glass in my unit is indeed brittle and the unit came to me with the characteristic chip in the corner, supporting the glass is original.
7) It is hard for me to imagine someone going to great expense to get a precision manufactured piece of coated glass just to scam someone by placing the unit on the used market like that.


No matter if the unit came with glass, or someone put the glass in there, I'm planning on upgrading mine to a real light-pipe panel.

 

[ic-racer]

After analysis of a Forscher back and the Rolleiflex back it is now clear what Rollei engineers had in mind.

The Forscher back needs to make up a distance between the 35mm film gate and the Polaroid pack film plane of about 10mm. The Rollieflex back has a film plane difference of only about 2mm.
The Forscher back needs to have direct contact between the fiber optic element and the Polaroid emulsion; they have to touch to form an image. The Rolleiflex back was designed with a dark-slide between the Polaroid film and the glass. A fiber optic plate won't work unless there is some mechanism for it to spring back toward the Polaroid emulsion to make contact.

Since the film plane distance is only 2mm, Rolliefliex engineers used a high-index of refraction glass that is positioned INSIDE the film gate; almost touching and dangerously close to the focal plane shutter (closer to the lens than the film plane). The result is supposed to project the focused image about 2mm farther back than the film plane.

 

[ic-racer]

Update.
So, knowing how the Rolleiflex back is supposed to work, and knowing that the glass doesn't touch the film plane of the Instant Film, it is probably unreasonable to expect a sharp image at anything except stopped down.

So, to make this happen a lot of things need to come together.

1) A working SL2000f or SL3003.
I have 4 and 2 still work!
2) Batteries for the above.
See my related post on batteries; I just upgraded the batteries in my SL3003 battery packs to low self-discharge nickel–metal hydride batteries. I already made a charging adapter.
3) Powerful flash to allow one to shoot at F11 or F16 with the ISO 100 instant film (of course the ISO 3000 film is gone).
See my related post on batteries for the powerful Rollei E36 Flash. Now powered by a 3-cell LiPo.
4) Film
Perhaps not available for long, but as of today I can still order more Fuji FP-100C.

I have been fiddling with this SL2000 Polaroid back since 2003 but never got it to work well.
Today I finally got some very nice, but very tiny, images. Like many things in art, I'm re-purposing what was once a professional proofing device (the Polaroid back) for the fun of just making tiny instant pictures for friends and family.

 

[Mr Bill]

So, knowing how the Rolleiflex back is supposed to work, and knowing that the glass doesn't touch the film plane of the Instant Film, it is probably unreasonable to expect it sharp image at anything except stopped down.

Hi, glad to hear you're getting some images. But regarding the "stopped down" issue, I doubt you need to. I'd expect nice sharp images even with a wide open lens. The glass is mainly just shifting the optical image rearward by roughly 1/3 the thickness of the glass - it's not necessary for the film to be in contact. (It's much like enlarging through a glass plate - you'd have to refocus slightly, but it would not be necessary for the glass to contact the paper.)

 

[ic-racer]

Yes, agree on the high refraction glass not needing to touch. I got caught up with that when trying to adapt the light pipe, which does need to touch.
Another possibility for the focus shift is the Fujifilm pack holds the film a millimeter back, compared to the original Poaroid packs. A millimeter is the error I found with testing. A millimeter error is massive when using a 50mm lens at 1.4; the image is a blurry mess.

 

[ic-racer]

Here is an observation. When removing a FP100c cartridge I noticed it was not seated all the way in. I thought that closing the back will snug the cartridge up against the film plane. Well, it doesn't. So, I believe all along I have not been pushing the cartridge and seating it up against the film plane. This is the cause of the poor focus.

Conclusion: it is not a bad idea to re-test items in the "doesn't work right" pile.

I suspect some might say "re-test items before throwing away" but I never throw away. I tend to keep everything, including broken, non-working stuff.