A-Power Holga Polaroid back - questions

[Giuseppephoto]

Hello everyone,

I have a few questions about a recently acquired A-Power "instant filmholder for holga 120" Polaroid back.

I bought the back off of ebay used at a price that was too good to pass up. It came with the box, the back, a stick on viewfinder and lens as well as the darkslide.

I finally loaded a pack of FP 100c in it today and took several shots. I tried 3 with the slip on lens and I was impressed at how "sharp" the shots came out... I took another shot without the included lens and well, I'll call that shot an artistic blur of sorts (ha ha).

Anyhow, here is my main question... I noticed that the shots that I took when I used the slip on lens that the images all had an excessive vignette (see examples). So much so that I almost can't make out the right side where the image is cropped off center. Now what I want to know is if there are any users of the same A-Power back that experience the vignetting. I tried pushing the lens on as far as it would go so I am pretty sure it's not that.

I'm using the back with a 120 CFN model Holga.

Oh, my 2nd question was - does anyone have a copy of the instructions that came with the back that would be willing to share ? - that's the only thing I'm missing from mine.

Thanks in advance!

 

[wildbill]

instant film is much larger than the normal 6x6 window. the lens' image circle isn't large enough to cover the instant film.

 

[Giuseppephoto]

Thanks wildbill.

I realize that FP100c is larger than 6x6 - my question pertains to the excessive vignette - "So much so that I almost can't make out the right side where the image is cropped off center."

In other words - the 6x6 portion of the frame is rounded due to the excessive vignette.

Does anyone here have experience with this issue/the A-Power Polaroid back and the vignetting like my examples?

 

[xya]

obviously that's what you get. if you google "holga 120 polaroid" you will see similar results. some people just crop the pictures when scanning and make you believe that they got a full picture. or they choose dark backgrounds so that vignetting doesn't show. however you have got very neat images compared to the rest.

 

[ciniframe]

Look through the slip on lens with you eyes. It should be a negative diopter lens (makes everything look smaller). If it does it is to bring the focus out to reach infinity. This is because they cannot get the Polaroid back close enough to the film plane so it would only work as a close focusing camera without the slip on lens. This also slightly increases the lens effective focal length. Others are right that the lens just does not have the coverage for the Polaroid back and I suspect that the rim of the slip on lens also shows up in the edges of the image circle. This may be the cause of the sharp fall off in the pictures. A better camera to adapt a Polaroid back to (although it would be a modification, not a simple add on) would be an old 6X9 box camera. The 100mm to 105mm or so lens on that type of camera would have almost enough coverage for the FP100c film.

 

[gone]

To a large degree, I'd guess that the extreme vignetting that you're experiencing is because you have something else stuck on the end of your Holga lens (your slip on lens). My Holga has difficulty covering 6x6 even without a filter. When I put a filter on it, things go from bad to worse in that regard. The first shot below is w/ no filter, the second shot is w/ a yellow filter by means of a slip on adapter. It's an adapter that I've used on lots of cameras w/o any problems, so its the Holga.

At first this bothered me, but then I realized, hey, its a Holga! Expecting it to behave like a more expensive camera was my real problem :} Since the standard lens is so recessed, the vignetting could possibly be fixed by taking a saw to the front of the lens barrel and sawing off some of that excess length.





I saw this recently. Its a way to line up your shot when making self portraits. Very ingenious, and very Holga.

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