pinhole cameras

Phil_F_NM said:
I can't say anything about a brand name pinhole as I build all my pinhole cameras. The 120 I built was made to accommodate a Graflex RH8 that is used on another body. I've found that proper film backs like the RH8 and RH10 or other brand equivalents, are the most inexpensive and reliable with most repeatable results. It's also nice to be able to simply slip in the back on the pinhole then switch to the Busch Pressman C. I know this is off topic a bit but figured the rollfilm transport information was relevant.

Phil Forrest
Click to expand...

Phil; Do you use the dark slide on the Graflex as a shutter on your pinhole rig?
 
What about a Gevaert Gevabox 6x9 box camera?

It's quite easy to take out the lens, it has a 'B' speed setting, two viewfinders, it's made of metal, you get 8 shots.

I presume there'd be some fiddling to do to get the pinhole bit onto the camera in exactly the right place so that the camera's aperture didn't get in the way of the light from the pinhole, but I'm sure you can manage that.

I'm wondering if it would be possible to fit the pinhole thing to the lens barrel in place of the lens and then you could even 'focus' it. Not that that would be necassary, but would it be fun to see what the effect would be?
 
seany65 said:
What about a Gevaert Gevabox 6x9 box camera?

It's quite easy to take out the lens, it has a 'B' speed setting, two viewfinders, it's made of metal, you get 8 shots.

I presume there'd be some fiddling to do to get the pinhole bit onto the camera in exactly the right place so that the camera's aperture didn't get in the way of the light from the pinhole, but I'm sure you can manage that.

I'm wondering if it would be possible to fit the pinhole thing to the lens barrel in place of the lens and then you could even 'focus' it. Not that that would be necassary, but would it be fun to see what the effect would be?
Click to expand...

Thanks for the suggestion. Pinhole lenses don't need focusing, but moving the lens will change the focal length. I think Phil's suggestion of a roll film back is a good one. There's lots of outside space around the film mechanism (4x5) for mounting a light chamber, or camera box.

I will have a look at a Gevabox so I know what it is. I found one source for a LASER cut 0.25 mm pinhole at $75 ea. It appears that it's not a common size for commercial production.

Anyway, I'm having fun drawing this stuff. I may order a film back as soon as I'm sure I can get some free or cheap shop time with my machinist friend.
 
I attached the Graflex rollfilm back to the pinhole box by using some wood and screws from a hardware store. I used my dremel tool to cut the notch into the wood slats so the RH8 slides in very snugly.

Using a dark slide for a shutter moves a lightweight pinhole camera too much.

I mentioned in a PM to PKR that I made a shutter out of a 3 1/4 floppy disc with the magnetic foil ripped out. The slider is driven by a stiff and very quick spring so as long as you don't bend the metal when taking the media out, you have an instant shutter that opens as fast as you want (according to how you attach a means to trigger it) and close as fast as the spring can drive it. I have mine completely hidden inside the camera, with a short cable release attached.

I need to do this to my 4x5 pinhole. Currently the shutter is a piece of tape, weighted down with four pennies and with a piece of black felt to "seal" the aperture a little better. When using film, exposures are still pretty quick and are within that "shaky zone" where there is not enough exposure time to overtake any camera shake so I have to be extra careful.
I really need to get out and shoot with that thing...

Phil Forrest
 
Here are a few photos of the 120 pinhole.

Camera front. Top of the short cable release visible.
pinhole1_E.jpg

The pinhole aperture is JB Welded to the back of a washer which is attached to the cigar box. This is a semi wide angle on 6x9 as the focal length is 81mm.

Camera back showing the rails I made to slide in the RH8 back.
pinhole2_E.jpg

This view is in the "locked" position as if the back were installed. The black tab of wood on the lower right side of the photo is screwed in with a screw that has a 3/8" long shank so it is free to rotate. When rotated 90 degrees to the top of the camera, the back (former box lid) is allowed to open. In this photo the left side is the hinge side. Only then can the film back be slid into place or removed. After sliding the film back in, the lid is closed, the black wood tab rotated down to lock the lid closed and that also locks the rollfilm back into place because of the tabs sticking out of the base which act both as locks and light baffles on a graflock back of a "real" camera.

Here is a view of the inside showing the shutter, felt light baffling, the tab of nylon I JB Welded to the floppy shutter metal, and also the shutter cable release. I used a very short cable release, so it was stiff enough to not need any internal support which would have complicated matters a bit.
pinhole3_E.jpg


Let me know if y'all need any pointers. The best art and camera repair shops are hardware stores...

Phil Forrest
 
Thanks Phil;

I'll study the photos and maybe ask some questions when I think I know what I'm doing.

JB Weld and gaffer tape..hard to get along without them.
 
PKR said:
Thanks for the suggestion. Pinhole lenses don't need focusing, but moving the lens will change the focal length. I think Phil's suggestion of a roll film back is a good one. There's lots of outside space around the film mechanism (4x5) for mounting a light chamber, or camera box.

I will have a look at a Gevabox so I know what it is. I found one source for a LASER cut 0.25 mm pinhole at $75 ea. It appears that it's not a common size for commercial production.

Anyway, I'm having fun drawing this stuff. I may order a film back as soon as I'm sure I can get some free or cheap shop time with my machinist friend.
Click to expand...


Here's a pic of mine:



Click on the pic to get a bigger version.
 
Phil_F_NM said:
Thanks! Not my original idea though. I forgot where I saw that but thought the floppy shutter was very creative.
I need to figure out how to reseal a graflex rh8 though. Ours has light leaks.

Phil Forrest
Click to expand...

My thinking is, that if I do this, I will build a camera around the 4x5 material surrounding the roll film unit. There should be plenty of room for drilling for small screw holes on the perimeter of the unit.

I use Lampblack mixed with rubber cement as a good light sealing material. If you try this, be careful, as Lampblack is a poison.

https://en.wikipedia.org/wiki/Carbon_black
 
PKR said:
Thanks Sean; from the photos it looks like the film to lens distance would produce a normal to slight telephoto FL?

Looks like a cool camera, pkr
Click to expand...

I dunno what the focal length is, but tunalegs says:

"Most 6x9 box cameras use a lens with a focal length of around 100mm. Some are slightly longer, and some are slight shorter. So far I have not encountered one that is not at least slightly wide. No point in worrying about it though, it is what it is."

According to oresteen.com:

[FONT=Arial, Arial, Helvetica]Focal Length mm[/FONT][FONT=Arial, Arial, Helvetica]6x9 Angle of View[/FONT] [FONT=Arial, Arial, Helvetica]35mm Equivalent[/FONT] [FONT=Arial, Arial, Helvetica]35[/FONT] [FONT=Arial, Arial, Helvetica]110[/FONT] [FONT=Arial, Arial, Helvetica]15mm[/FONT] [FONT=Arial, Arial, Helvetica]38[/FONT] [FONT=Arial, Arial, Helvetica]106[/FONT] [FONT=Arial, Arial, Helvetica]17mm[/FONT] [FONT=Arial, Arial, Helvetica]47[/FONT] [FONT=Arial, Arial, Helvetica]94[/FONT] [FONT=Arial, Arial, Helvetica]20mm[/FONT] [FONT=Arial, Arial, Helvetica]58[/FONT] [FONT=Arial, Arial, Helvetica]82[/FONT] [FONT=Arial, Arial, Helvetica]25mm[/FONT] [FONT=Arial, Arial, Helvetica]65[/FONT] [FONT=Arial, Arial, Helvetica]75[/FONT] [FONT=Arial, Arial, Helvetica]28mm[/FONT] [FONT=Arial, Arial, Helvetica]72[/FONT] [FONT=Arial, Arial, Helvetica]70[/FONT] [FONT=Arial, Arial, Helvetica]31mm[/FONT] [FONT=Arial, Arial, Helvetica]75[/FONT] [FONT=Arial, Arial, Helvetica]68[/FONT] [FONT=Arial, Arial, Helvetica]33mm[/FONT] [FONT=Arial, Arial, Helvetica]90[/FONT] [FONT=Arial, Arial, Helvetica]58[/FONT] [FONT=Arial, Arial, Helvetica]39mm[/FONT] [FONT=Arial, Arial, Helvetica]100[/FONT] [FONT=Arial, Arial, Helvetica]53[/FONT] [FONT=Arial, Arial, Helvetica]43mm[/FONT] [FONT=Arial, Arial, Helvetica]105[/FONT] [FONT=Arial, Arial, Helvetica]51[/FONT] [FONT=Arial, Arial, Helvetica]45mm[/FONT] [FONT=Arial, Arial, Helvetica]115[/FONT] [FONT=Arial, Arial, Helvetica]47[/FONT] [FONT=Arial, Arial, Helvetica]49mm[/FONT] [FONT=Arial, Arial, Helvetica]120[/FONT] [FONT=Arial, Arial, Helvetica]45[/FONT] [FONT=Arial, Arial, Helvetica]52mm[/FONT] [FONT=Arial, Arial, Helvetica]125[/FONT] [FONT=Arial, Arial, Helvetica]44[/FONT] [FONT=Arial, Arial, Helvetica]54mm[/FONT] [FONT=Arial, Arial, Helvetica]127[/FONT] [FONT=Arial, Arial, Helvetica]43[/FONT] [FONT=Arial, Arial, Helvetica]55mm[/FONT] [FONT=Arial, Arial, Helvetica]135[/FONT] [FONT=Arial, Arial, Helvetica]41[/FONT] [FONT=Arial, Arial, Helvetica]58mm[/FONT] [FONT=Arial, Arial, Helvetica]150[/FONT] [FONT=Arial, Arial, Helvetica]37[/FONT] [FONT=Arial, Arial, Helvetica]65mm[/FONT] [FONT=Arial, Arial, Helvetica]180[/FONT] [FONT=Arial, Arial, Helvetica]31[/FONT] [FONT=Arial, Arial, Helvetica]77mm[/FONT] [FONT=Arial, Arial, Helvetica]200[/FONT]


The distances/D.O.F. 'scales' on the front of the lens are:

5ft - 10ft, 13ft - 20ft, 23ft - inf.

with the 3 red focusing indices on the lens being at the ' - '.

tunalegs also says:

"Edit: playing with the DOF calculator, assuming a focal length of between 90 and 100mm, and the known f/stop of f/8, the actual focus distance for 23' to infinity, would be around 50 feet. Depth of field then covers the rest of the indicated zone..."

So I'm not sure what the focal lenght actually is, but I've no reason to doubt tunalegs.

Thanks again to tunalegs for the info.
 
seany65 said:
I dunno what the focal length is, but tunalegs says:

"Most 6x9 box cameras use a lens with a focal length of around 100mm. Some are slightly longer, and some are slight shorter.

SNIP


The distances/D.O.F. 'scales' on the front of the lens are:

5ft - 10ft, 13ft - 20ft, 23ft - inf.

with the 3 red focusing indices on the lens being at the ' - '.

tunalegs also says:

"Edit: playing with the DOF calculator, assuming a focal length of between 90 and 100mm, and the known f/stop of f/8, the actual focus distance for 23' to infinity, would be around 50 feet. Depth of field then covers the rest of the indicated zone..."

So I'm not sure what the focal lenght actually is, but I've no reason to doubt tunalegs.

Thanks again to tunalegs for the info.
Click to expand...


One of the things that's most interesting about pinhole lenses is that they have an almost infinite depth of focus and depth of field. Look at the photo posted by the Col. The drink can and far wall are all in focus. Not sharp by modern lens terms but very good for a pinhole lens.

Here's the math for focal length, etc...
http://pinhole.stanford.edu/pinholemath.htm

http://pinhole.stanford.edu/ip.html
 
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