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View Full Version : Question: move pinhole up or down?



bino
02-21-2005, 06:20 PM
I`m a little bit confused. :)
made a box for 13x18 paper (60 mm, 0,3 mm, f-stop~205) , first time in my life I developed the paper in my new darkroom by myself and alone.Great Experience! Fun!! :)
That`s the paper negative ( scanned ).
Must I move the pinhole up or down to get more on the paper? Attached files http://f295.f295.org/uploads/innenhofblackya_3026.jpg (http://f295.f295.org/uploads/innenhofblackya_3026.jpg)

johnr
02-21-2005, 06:47 PM
i vote for Down. this is making my head hurt!

taco
02-21-2005, 07:11 PM
Must I move the pinhole up or down to get more on the paper?
That's not a question of moving the pinhole but of moving the paper. Even if the pinhole is not in the middle of the box (but with a 13x18 box and a ruler that should be no problem) it would be a shame to destroy a pinhole-camera. Just position the paper on a better place: If possible, take a larger negative, mark it in the camera, take a shot, develop, regard and mark again the "good" exposed size of the negative in the camera
taco

JoeVanCleave
02-21-2005, 07:22 PM
I like your image. Here's the same image reversed in PS.

I would move the paper negative "up" in the camera, so the image circle is better centered on the paper.

Keep in mind that the image is projected through the pinhole to the film plane upside down. So, as we view the image upside down, moving the paper "up" (or toward the right-side image's "down") will better center it.

Attached files http://f295.f295.org/uploads/innenhofblackya_3026a_8351.jpg (http://f295.f295.org/uploads/innenhofblackya_3026a_8351.jpg)

bino
02-21-2005, 07:28 PM
Thank`s to you all. I hope the inside of my camera has enough place to move the paper.

earlj
02-21-2005, 09:22 PM
I like the image just as it is, both positive and negative. However, you should be choosing the image that you want to make - your camera should be a slave to you and not the other way around.

None of my cameras show any noticeable vignetting - I think it is time that I built some wider angle cameras. I like seeing what happens to the image as the light intensity falls off.

bino
02-22-2005, 03:04 AM
Thank you, earlj. You are right. I have to be the master.
This morning I will tape the paper and see, what happen`s. Maybe the paper has moved by itself (to nervous during my first developing to look at this!)Same effect once more, then I think I make
a new camera and have a camera with a special effect for special pictures.
bino

bino
02-22-2005, 03:16 AM
camera 18x13 paper, 60 mm, ~0,3 mm, 205

Attached files http://f295.f295.org/uploads/pict2512_3153.jpg (http://f295.f295.org/uploads/pict2512_3153.jpg)

ImageMaker
02-22-2005, 08:16 AM
For whatever it's worth, if your camera is to sit on the ground, it might well be worth making it with the pinhole above center so you get an upward view while keeping the back vertical -- this will act like front rise in a view camera, keeping the verticals in your scene from converging at the top, and provide a view with more sky and less ground. Of course, the question is whether that's what you want...

However, I don't think the circular appearance of the image is entirely due to light fall-off -- it's too sharply demarcated at image top (camera bottom), though the bottom does show the light fall-off we'd expect from a wide angle image. I think a solid part of the camera is interfering with the light path, either inside or outside the pinhole. The wide angle of a short-distance pinhole means you may need a conical, rather than cylindrical opening through the body, and this is likely an alteration that can be done without destroying the camera (assuming you want a full-frame image rather than the vignetted circular image you've shown). If your pinhole isn't permanently mounted, you may also be able to move the pinhole relative to the body opening. If the obstructing edge is inside, you'll want to move the pinhole up a little; if outside, you'll want to move the pinhole down.

bino
02-22-2005, 05:04 PM
Good news: camera works correct! :)
Thank you all for your help. Where else as on this site is it possible to learn so much about the "right place for the pinhole" and all the varations of pictures you can get by moving the pinhole up or down in such a short time. :)
After sleeping about this problem I decide this morning to look after the "paperholder" and correct it.
I used only rollfilm cameras before my first papercamera and there was no need to think about what happens with the film, when I put the camera in my bag and go for a walk. He always stays on his place. :) I was careless with the paper and some rapid movements ...
The corrected "paperholder" gives me this shot on a windy and cold morning.
Great fun!
Now I have to learn about exposure times!
Thanks,
Bino Attached files http://f295.f295.org/uploads/littlebridge_7180.jpg (http://f295.f295.org/uploads/littlebridge_7180.jpg)