Polaroid 800 4x5 Conversion

[RFH]

Fragomeni: Yes, the 110/120 series have lensboards that allow you to change lenses quite easily. Just screw off the rear retaining ring. My 800 has the front element pressed in place, so I'm afraid that installing another lens will require an irreversible modification of the standard. And maybe damage to the lens itself.

Different lenses have different focus curves, which relates to the physical shape of the RF cam. 127 is pretty close to 130, so maybe it doesn't make much of a practical difference. The RF cam is a small thing, so I wouldn't bet on just modifying it with a file by trial & error. When attaching a film holder you are moving the film plane back, so you'll need to readjust the RF anyway.

 

[keytarjunkie]

Fragomeni: My 800 has the front element pressed in place, so I'm afraid that installing another lens will require an irreversible modification of the standard. And maybe damage to the lens itself.

Yup, that part was the most enjoyable 😀 opening up the old lensboard and cutting through the lens...

Different lenses have different focus curves, which relates to the physical shape of the RF cam. 127 is pretty close to 130, so maybe it doesn't make much of a practical difference. The RF cam is a small thing, so I wouldn't bet on just modifying it with a file by trial & error. When attaching a film holder you are moving the film plane back, so you'll need to readjust the RF anyway.

I'm pretty sure 127 and 130 are close enough that it doesn't even matter. 150 or 90 on the other hand, aren't.

 

[Fragomeni]

Hmm, now I'm very curious about this! 127mm and 130mm are very close but as I'm sure we all know in photography absolute sharpness means precision and exactness. That 3mm difference is certainly enough to make major difference in focus. I have a few MF rangefinders (Linhoffs and Horseman) that operate with precision cut cams specific to each lens (each cam is made with the lens because even consecutive lenses of the same production run can have slight differences in focus and focal characteristics). With these I know for a fact that if the cam isn't cut perfectly for the lens then the lens will not focus optimally or absolutely perfectly sharp using the rangefinder mechanism. I guess it all comes down to how precise you want to be but it seems logical that using a 4x5 rangefinder probably has something to do with wanting the sharpest and highest quality image 🙂

Keytarjunkie, do you think you might be able to pop some ground glass in your camera when its done to test the focus to rangefinder relationship with your new lens and solve this once and for all for us? This is the perfect solution to ground glass which should be easy to make and fit your camera perfectly. Let us know if you do it!

 

[keytarjunkie]

I just got my ground glass in today! And am currently attempting to line it up in the holder properly. So funny you should mention that!

I'll ask Nate (option8). He should know.

 

[Particular]

Fragomeni:
Different lenses have different focus curves, which relates to the physical shape of the RF cam. 127 is pretty close to 130, so maybe it doesn't make much of a practical difference. The RF cam is a small thing, so I wouldn't bet on just modifying it with a file by trial & error. When attaching a film holder you are moving the film plane back, so you'll need to readjust the RF anyway.

Interesting thread developing here.
I haven't seen the cams on these polaroids, but I have recently filed the a cam on a Linhof technika 70, matching it to three lenses. If you have installed ground glass, and you have your new lens set to infinity, it should be doable. With a lot of patience, checking glass then checking RF, marking it and then filing and eventually sanding, you can be very accurate.
Generally installing a shorter lens means removing material, while a longer lens would require a longer curve. Going from 130mm to 127mm should work. I managed to glue a strip of aluminum to my cam for a longer lens, which I then filed to match. I also added super glue in a spot where I took too much away to build it back up.

 

[Fragomeni]

Very interesting indeed. Just a quick idea. Plumbers epoxy putty would be an ideal material for adding to a rangefinder cam. It is very easy to work with, dries rock solid, and is easily filed and sanded. This is also the material I'm using to fill in gaps between the body and the film holder. It makes the body completely flush to the holder and seals all light leaks.

Another question: Does any one know if the top cover with the coupled viewfinder/ rangefinder from a 110b can be put on the 800? Are the rangefinder mechanisms the same so that the top covers could just be switched out? Thanks.

 

[keytarjunkie]

Very interesting indeed. Just a quick idea. Plumbers epoxy putty would be an ideal material for adding to a rangefinder cam. It is very easy to work with, dries rock solid, and is easily filed and sanded. This is also the material I'm using to fill in gaps between the body and the film holder. It makes the body completely flush to the holder and seals all light leaks.

Another question: Does any one know if the top cover with the coupled viewfinder/ rangefinder from a 110b can be put on the 800? Are the rangefinder mechanisms the same so that the top covers could just be switched out? Thanks.

Ah epoxy putty! That's what I need.

They are not the same. The 110B/900 finder only fits on the 160 because of the location of the focusing arm or something important like that.

 

[Fragomeni]

Ah epoxy putty! That's what I need.

Yea, its fantastic stuff. I've been using it for years to make everything from saxophone mouthpiece modifications to cameras. The trick in using it is to coat whatever surfaces you don't want it to stick to in a moderate layer of Vaseline/ petroleum jelly (make sure this is thoroughly cleaned off before using the camera and loading film of course). I built up some walls to give extra support and security to the film holder as well as to provide a light trap and although at the moment it looks a little like a highschool sculpture project when its sanded down it'll look fine. I dont care what it looks like in t end as long as it works 🙂

They are not the same. The 110B/900 finder only fits on the 160 because of the location of the focusing arm or something important like that.

I see. So then how difficult would it be to swap out the whole rangefinder mechanism and the top cover with one from a 110B? Its been done here but the person mentions nothing about how they did it. I'm wondering if it was just a simple swap?

 

[shadowfox]

I am close to post my own.
But wanted to wait until I developed the test negs.

You guys motivated me to hurry up. 🙂

 

[Fragomeni]

I went searching for a 110b today at some local antique shops and came up empty handed. I found a 900 and thought about buying it to try to swap out the rangefinder top plate with the one on my 800 conversion but I haven't yet gotten an answer on whether or not thats possible and I couldn't remember if the 900 and 800 have the same 130mm focal length lenses. I just don't want to have to mess with modifying the RF cam. If someone can confirm that the 900 lens is 130mm then maybe I'll go back tomorrow and pick it up. Also, if anyone has a spare 110b they'd part with let me know please (I notice this forum doesn't have a classifieds section so I hope I'm not breaking any rules by asking).

 

[keytarjunkie]

I went searching for a 110b today at some local antique shops and came up empty handed. I found a 900 and thought about buying it to try to swap out the rangefinder top plate with the one on my 800 conversion but I haven't yet gotten an answer on whether or not thats possible and I couldn't remember if the 900 and 800 have the same 130mm focal length lenses. I just don't want to have to mess with modifying the RF cam. If someone can confirm that the 900 lens is 130mm then maybe I'll go back tomorrow and pick it up. Also, if anyone has a spare 110b they'd part with let me know please (I notice this forum doesn't have a classifieds section so I hope I'm not breaking any rules by asking).

Take a look at the "classifieds" button at the top of the page.

The 800 and 150 don't match with the 110A, 110B, 120, 160, and 900, as far as I know. The place where the cams attach is in a different location, in order for the rangefinder to work properly with a particular lens all you need is the right cam for it, and you can usually modify one that you have so that's less of an issue.

 

[RFH]

I finally managed to get rid of the light leaks. Did a new calibration of the lens and RF, and it looks pretty accurate. And my first batch of 9x12 film (Foma 100) sheets just arrived, so I'll try shooting a few frames today to see how it looks.

 

[shadowfox]

I finally managed to get rid of the light leaks. Did a new calibration of the lens and RF, and it looks pretty accurate. And my first batch of 9x12 film (Foma 100) sheets just arrived, so I'll try shooting a few frames today to see how it looks.

Do you mind sharing how you hunted down the light leaks?
I am also on that stage.
The testing sheet that I exposed yesterday was full of light-leaks.

 

[shadowfox]

I went searching for a 110b today at some local antique shops and came up empty handed. I found a 900 and thought about buying it to try to swap out the rangefinder top plate with the one on my 800 conversion but I haven't yet gotten an answer on whether or not thats possible and I couldn't remember if the 900 and 800 have the same 130mm focal length lenses. I just don't want to have to mess with modifying the RF cam. If someone can confirm that the 900 lens is 130mm then maybe I'll go back tomorrow and pick it up. Also, if anyone has a spare 110b they'd part with let me know please (I notice this forum doesn't have a classifieds section so I hope I'm not breaking any rules by asking).

I would stick with the 110 series because the quality of the shutter and lens.
Any other model is not worth the hassle (IMHO).

 

[kuzano]

ah ah ah.... don't forget

ah ah ah.... don't forget

I would stick with the 110 series because the quality of the shutter and lens.
Any other model is not worth the hassle (IMHO).

The great Yashica Yashinon lens in Polaroid shutter on the 120. Loverly to say the least.

 

[shadowfox]

The great Yashica Yashinon lens in Polaroid shutter on the 120. Loverly to say the least.

Kuzano,
Thanks for the addition, of course, the Yashinon shutter/lens qualifies as good.
I was referring more to the plastic lenses or severely handicapped shutter that was put on 900, 80, etc. models.

 

[RFH]

Shadowfox: For the first round of leak checking I put a flashlight into the extended bellows, mounted a film holder and turned off the lights. Then I shot a few paper negatives with some old paper to see exactly where the leaks were.
I had glued two leather strips along the film gate to act as light seals, but all they did was push the holder outwards and create the leak. I removed them both, and the holder sits flush against the edge now. I took good care to foam seal both film chambers along all the edges.
Tried it yesterday with a piece of VC paper rated at ISO 12, and it looks fine now. Maybe it's just the format blowing me away, but I think the lens is quite nice. If it had a proper shutter, I wouldn't mind keeping it.

 

[Fragomeni]

Take a look at the "classifieds" button at the top of the page.

Geeze, sometimes I wonder where my brain is. I looked all over this forum and was pretty pissed that it seemed to have no classifieds section. Thanks for the heads up! :bang:

Maybe it's just the format blowing me away, but I think the lens is quite nice. If it had a proper shutter, I wouldn't mind keeping it.

RFH, you should definitely think about keeping the lens. The image looks fantastic! Just get a 110b and do another conversion and you'll have two cameras to play with. I thought about chopping up the 800 and putting on another lens but I'm going to give it a chance with the original lens and the EV exposure system which may actually be advantageous in street shooting scenarios where it eliminates shutter speed and aperture combination decisions. Just plug in the right EV to make your exposure the way you want to go!


Update on the project: I finished the 800 conversion today. I added a little more epoxy to try to maintain a decent shape and painted it silver to attempt to make it at least moderately match the rest of the camera. In the end I care very little about how it looks as long as it works and I think it's ugliness is quite charming. Most of my homebrew cameras are ugly so I've come to accept and admire that quality in them which seems to speak to the handmade aspect of them.

Here is a picture of the ugly beauty mounted with a Pentax V spot meter and sitting on my 20x24 mammoth.

Good news! Tonight I snagged a 110b! Soon as it gets here I'll give it a thorough check up to make sure everything is working as it should be and if everything is good I'll start the next conversion. I think I'll go for the same deal as with the 800 and I'll probably try to make it look a little cleaner but still a little ugly 😀

 

[RFH]

Yes, it looks good, doesn't it? Of course the framing and focus are a bit random because I had to put the camera on the ground for a long exposure. But the metal in focus is rendered beautifully.

I shot a few Foma 100 negatives yesterday, but they came out a bit flat, so I'll have to work on the contrast. Sure they'll scan just fine, though.

People are always talking about how triplet lenses are inferior. Don't believe the hype. But I still think the shutter is a bit cumbersome to work with.
I'd love to get a 110B, but they are quite scarce in Europe and hence very expensive compared to the US. I had my friend in NYC bring the $10 800 back to Denmark, but I doubt he'll want to do that again...

 

[shadowfox]

Francesco, I agree, ugly is endearing. Can't say it's yours unless you can explain the ugliness 🙂

RFH, forgot to comment, your test shot is excellent!

Update on mine, taped a major light leak yesterday, but still have some to go, it created bands of light going from the point of film insertion into the 4x5 holder.