3x4 vs. 4x5 conversions

<p>I recently converted a Polaroid model 160 camera to 4x5, I also built one in 3x4, they both use plastic double dark holders. What I want to know is which way is better? When going to 4x5 you are also using a bigger % of the image circle than it was designed for. So I built one in 3x4 and find it slimmer, lighter and just wanted another opinion on this format expansion vs. staying with the 3x4 format...........has anyone built one like this before, if not why?</p><div></div>

<p>Well you can be the judge of that now can't you.</p>

<p>I've just got the 3x4 done yesterday and will do more testing when the rain stops.....have you seen one done this way before?</p><div></div>

<p>I can't say I have and if it does cover 4x5 it will be something. but I bet it gives you a unique image that is unique with the fall off to the edges. One of a kind camera I like to call them.</p>

<p> Weather here has been off kilter too. but it did not stop me from going out into a cemetery during a snow storm. I though did draw the line during the freezing rain when I did a 360 just getting out of my parking spot. :-)</p>

<p>This camera can't cover 4x5 because it uses a 3x4 holder..........I do have another 160 that is 4x5.<br>

Both get full neg coverage without vignetting. But I'm partial to the 3x4 version.</p>

<p>I would love to see pictures from both could you put pictures or links to some and larger files as the edge is where I want to see.</p>

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<p>Having converted a 160 camera to 120 film I am now in the process of converting a 110A to 5x4. Your 3x4 conversion looks much neater than any 5x4 conversion I have ever seen and if 3x4 film and holders were more common I think I would do this too as it retains the original image size (more or less) and therefore, the viefinder will be a more accurate representation of what is on the film.<br />However, as 5x4 is a much more common format, I think I will continue with this size.</p>

<p>EDIT: That last line sounds a bit dismissive of your choice of a smaller format which was certainly not the intention!</p>

<p> I gave the 3x4 a bit of thought before I went ahead and built it, for the very reasons you mention. Ilford does special orders every spring so you can get most of their film in 3x4, factory cut. Freestyle photo also stocks Efke 3x4 100asa or you can cut your 4x5 film down to size yourself. When we convert these Polaroids to 4x5 we are using a bigger portion of the lens image circle, when keeping it in 3x4 you are using the sweetest part of the image circle...........like the engineers intended. I have a Pola 160 that I built in 4x5 with a very slim back but find the camera to be clumsy to use. I would like to explain why this way is better but I don't have the room here. The factory used those lenses based on negative coverage and they would have chosen another lens if the camera was intended for 4x5 use, with a <strong>bigger</strong> image circle. I wouldn't have gone down the 3x4 road unless I thought it had some advantages over 4x5. Based mainly on the above I think I'll stay with 3x4. The 160 I did in 3x4 frames/composes more accurately and is 4oz lighter and so slim you can leave the old 2 window R/F if you want. The holders used are smaller and it looks more like a factory build. Just my spin on the Pola thing.</p>

<p>Please post photos of your 3x4 camera. I'd be interested in seeing what method you used for the conversion.</p>

<p> Patrick I will be posting some picks of the build as soon as the holidays are over, just too busy with work & x-mas to do it now. I keep changing the holder design so I think it would be best to wait until I do another 160 with the new holder box/plate that I've come up with. I want to be able to store a lens shade, cloth, cable release and filters in the small door & with the new adapter the door will be much bigger because the holder box is only 1/16" bigger than the holder around it's perimeter.So the door will be about 3/4" longer and will house everything I need to shoot with. This would also work on a 4x5 version, making it about as small as I think it can be. The 3x4 160 isn't really a conversion, it's just a mod that takes it to cut sheet holders instead of the original roll film (no law suits here). I've seen so many of these conversions I just had to give it a try. To those who want to give it a go I would suggest starting on a cheap model in the beginning and move along to your camera of choice, this way you won't wreck an expensive model..........and you will learn and change things as you go. Patrick this last part doesn't apply to you as I've seen some of your stuff before I even got started.</p>

<p>I was having a play around with my 110A yesterday to see where I am going to place the film holder. If I wish to retain the separate viewfinders then the film holder will be about 10mm too low and the bottom 10mm of the film area will receive no image.</p>

<p>I have not yet decided if I am going to live with that and accept a more rectangular frame or do something with the rangefinder housing and get the full frame area.</p>

<p>Steve there are only two ways to get 4x5 from your 110a. One way (most used method) involves moving the film plane back about an inch, with this method you are above the height of the R/F with just a very small area near the windows that will need trimming. The other method of getting 4x5 is like the Byron camera, where you add spacers to raise to R/F height ................this will solve the offset problem and center your holder, but it also means making a new bellows with the back end of the bellows now measuring 4x5 instead of the original 3 1/4 x 4 1/4 size. This method is very much slimmer, lighter and nowhere near as thick because the holder is "in house". I've done a 160 in 4x5 using the first method, but the camera I have on Photonet is <strong>3x4</strong> not 4x5. I hope you start your build with a cheaper model and sort out the details before you do the 110a, I have 2 - 110a's I plan on doing when I'm done sorting out the details. I will be posting pics of my 160 3x4 build after the holidays but that won't help you much because the 4x5 build is done a bit differently. There are older posts on here that might help you. On youtube there is a video of a 900 pack-film conversion which would help you out with some dis-assembly stuff and maybe give you some ideas too. You'll also need some tools & time but it's worth it. Good luck Steve & take your time.</p>

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<p>One way (most used method) involves moving the film plane back about an inch, with this method you are above the height of the R/F with just a very small area near the windows that will need trimming.</p>

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<p>I have already moved the film plane back about 3/4" and moved the lens standard stop mechanism to suit. Another 1/4" is easy. And now that you mention it I see that an extra 1/4" will bring the surface onto which the film holder rests in line with the back of the plastic rangefinder housing with just a bit of the chamfered area area below the viewfinder windows needing removal. I think this is the method I will use.</p>

<p>I have the use of a CNC drill/router and it is quite easy for me to make up pieces to try out. Tomorrow I will make a second back plate from 1/4" material to go under of the plate I have already made to bring the film plane 1/4" further back.</p>

<p>Just holding up the back plate I already have next to a film holder it appears that the area under the viewfinder windows only needs to be removed by about 1/8" (vertically) to centre the film holder so it seems like a possibility.</p>

<p> Steve when I did the 160 model in 4x5 what I did was attach a 5/16" piece of MDF directly on top of the door. I had to notch out the hump area where the red button is & some of the inside area of the rear door as well. I did leave the back door as one piece for strength this way it was stronger. I can also open the camera if I want. I'm a left eyed shooter and because the 4x5 was my first build attempt I decided to leave the double window R/F mostly because I didn't know how to add a 900 R/F at the time. I do now thanks to Option 8 and his advice and website. I can still shoot with this camera left eyed an all, just keep the back only as thick as the holder it houses and that's the best you can do with this method of expansion. Steve you will also be using a bigger % of the image circle (with stock lens) than was used in it's original format, I will be posting pictures of negatives that show what I mean by this. If you use a stock lens be it a glass triplet like the 160 has or the Rodenstock lens you will be taking a baby step backward by expanding to 4x5 using this method + a stock lens which was designed for a 3 1/4 x 4 1/4 camera. That is why I went to a 3x4 design and it's easier to build, like a pack-film cam but use a 3x4 holder in place of the P/F holder. My 3x4 holds everything I need except extra holders and the camera closes without any extra help or shaving down of infinity stop tabs........yes you will have to do that too. Forge ahead Steve while you have the Polar fever.</p>

<p>Being that you have access to a mill....................</p>

<p>I got a few of my first test shots scanned, taken with my first Polaroid 4x5 conversion. These are low res and still show dust & scratches, grrrrrrrrr. The R/F seems to work very well and all were taken hand-held, no cable release either........like it was designed to be used originally.</p><div></div>

It looks like your film plane is farther back from the factory position. Did you have to re-calibrate the rangefinder?

<p>Art, the film plane moved a little because the plate/holder thingy is attached right on top of the rails inside the body. This move made the rounded corners of the film gate fall outside of the neg area, so the resulting negatives have nice square corners. Art what comes along with that is the need to relocate the infinity stop plate rearward until you achieve perfect focus at infinity on whatever you use as ground glass, I use plastic. The rangefinder works regardless of the film plane location, it's adjusted for horizontal & vertical @ infinity like usual.</p>

<p>Thank you, kindly!</p>

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<p>I got a few of my first test shots scanned, taken with my first Polaroid 4x5 conversion. These are low res and still show dust & scratches</p>

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<p>Is that the full image on the film? If so the definition in the corners looks fine to me.</p>

<p>I have got the back plate (two stacked plates actually) finished for mine and I have removed a little bit of the moulding under the rangefinder window and the metal plate below it so that now a film holder fits centrally. I have made a dummy film holder with a matt plastic screen so I can check the focus and I think I have now got the lens in the right place for infinity focus. I think I will take a couple of shots with the film holder gaffer taped in place before I decide on a clamping system.</p>

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<p>Steve you're aware that you will have borders of unexposed film ................right. I think you'll have maybe a 1/8" border because the film plane hasn't moved back far enough. When I did my 4x5 I sat a 5/16" spacer on top of the flat section of the rear door, yours is sitting on top of the backside of the front body like my 3x4 camera or a pack-film type of conversion. So this will fall a little short of full coverage..................I wouldn't worry about it though, you'll have a much slimmer and easier to use camera in the end, even if it doesn't get full neg coverage. When measured from the old film gate to the new relocated film location it's something like an inch and a bit. Take a big piece of the plastic you use for ground glass and by shimming it farther and farther away you'll see when you get full 4x5, mark a 4x5 border in magic marker on the plastic and when you get enough coverage build your holder to match that measurement. Steve I never checked this out when I did my 3x4 cam so I don't know how much I went over the original size, but I do know that the rounded corners are gone on my negatives so it did get some expansion. My holder sits flush with the door just like yours does so it's gonna just about cover 4x5 but not fully. Hey it's not to late to make it thicker by doing the coverage test above or build it using 3x4 holders which will get full neg coverage. I would live with it, especially if your scanning the negs vs. using an enlarger. It's slim looking, I love it.</p>

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<p>Steve you're aware that you will have borders of unexposed film ................right. I think you'll have maybe a 1/8" border because the film plane hasn't moved back far enough.</p>

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<p>Quite possibly but once the first plate is in place and fixed to the body I can easily experiment and add spacers and move the front standard until I get what I want.</p>

<p>When I use my dummy ground glass/filmholder I do get full coverage though. The window in that is 98mm x 120mm which is very close to the image I have just measured on a piece of film taken with my Speed Graphic. I think a trial with it all gaffer taped together is in order today.</p>

 

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<p>I wouldn't worry about it though, you'll have a much slimmer and easier to use camera in the end.</p>

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<p>It does look quite compact so I may live with it as it is and make do with the reduced image size. I think the deciding factor will be the extra bulk of whatever I choose to hold the film holder in place and how far I can accept that going back whilst still being able to use the viewfinder.</p>

<p>At the moment I am drawn between using three or four low profile clips and building a more traditional sprung ground glass frame. I could always make it modular and have both!</p>

<p>Does anyone know whats involved with the 'Spacer to the view finder' method. I know a plate has to be cut, but doesn't a new post to the focusing cam need to be made too?</p>