Argenticien
Dave
Greetings all. I thought I'd share a process that I did, in case useful to others. Our local photo group here is planning an outing on Worldwide Pinhole Photography Day (27th April) so I thought I'd better get ready. This is my first pinhole; why start small? thought I, and set about adapting a Speed Graphic.
First I removed the 135 mm Optar (my only lens) from its lens board, then traced that onto scrap mat board:
After cutting it out with an X-Acto knife, I had this:
I measured to find and mark the center, then blackened the back to slightly reduce light bouncing around back there:
At this point, I mounted the board on the camera, took it into a dark closet, and shone a flashlight/torch around the edges of the board. It leaked light, so I needed light seals. My first try was with civilian green felt, the kind meant to stop the rough feet of sculptures, tchotchkes, etc. scratching table-tops. It proved too thick, so the board would not fit under the clips. What you're seeing here is actually my second attempt. I used 1 mm thick Jon Goodman seals. (I had hoped to avoid consuming the good stuff, but it was necessary.)
Left: win. Right: fail --
You can see, maybe, that Jon's 1 mm stuff is thinner:
This time, the mat board fit under the camera's clips. On to the actual pinholery... [Continues...]
--Dave
First I removed the 135 mm Optar (my only lens) from its lens board, then traced that onto scrap mat board:
After cutting it out with an X-Acto knife, I had this:
I measured to find and mark the center, then blackened the back to slightly reduce light bouncing around back there:
At this point, I mounted the board on the camera, took it into a dark closet, and shone a flashlight/torch around the edges of the board. It leaked light, so I needed light seals. My first try was with civilian green felt, the kind meant to stop the rough feet of sculptures, tchotchkes, etc. scratching table-tops. It proved too thick, so the board would not fit under the clips. What you're seeing here is actually my second attempt. I used 1 mm thick Jon Goodman seals. (I had hoped to avoid consuming the good stuff, but it was necessary.)
Left: win. Right: fail --
You can see, maybe, that Jon's 1 mm stuff is thinner:
This time, the mat board fit under the camera's clips. On to the actual pinholery... [Continues...]
--Dave
Argenticien
Dave
[Continuing...]
I was working with 36 AWG brass foil from A. C. Moore. From here, on, I followed rather closely these instructions from Silverbased. I did a few practice holes in scraps of aluminum sheet metal that I had lying about, then went to the brass. The only sphere I could find was from the end of a pull-chain on a lamp. Borrowing it, I hammered a dimple into the foil:
Then with 400 grit sandpaper, I sanded the back ("outie") side of the dimple until it was flat and in fact somehow got a sub-dimple that went the reverse way:
Turning the foil back over, I then pricked it with a sewing needle (yeah, a needlehole, not a literal pinhole):
The Silverbased instructions suggest not going all the way through with the needle, but rather making a needle-end-shaped even tinier dimple, then sanding off the end of the that to make a hole. My needle went through, though. I then flipped the foil over, sanded any shards off the back, cleaned the foil of shavings/dust, and went to my scanner. I covered all edges of the foil with paper to avoid scratching the scanner glass:
Scanning at 4800 dpi, measuring the hole in pixels, and doing the math, I found the hole was about 0.16 mm in diameter(!!!):
This is less than half the 0.45 - 0.50 mm size that Mr. Pinhole recommended for 4x5 at about 125 mm focal length (i.e., with the standard as far back as it goes). So back to the beginning of the brass -- hammer -- needle process. Next one was 0.45 mm -- spot on:
I cut the brass to about 4 x 5 cm around each hole, chamfered the corners to stop them snagging on things, and sanded the edges to remove any burrs:
I cut a hole at the center of the lens board with a Forstner bit that I happened to have:
Regrettably it minced the face of the final lens board a bit, after of course having cut cleanly on some practice holes that I did in junk board. Anyway I affixed the pinhole plate to the back of the lens board with electrical tape. (Use gaffer's tape if you have it.) --
I centered the pinhole in the lens board by eye. Theoretically, you should very perfectly center it somehow. I think it's close enough:
And I labeled the pinhole as to diameter lest I confuse myself ("which one is this?!") in future. Finally, here is the finished Speedhole! --
I sized it to work at the stops for the 135 mm Optar. This means it will have about the same FOV as the Optar, so if I want to I can compose on the ground glass using the Optar, then swap in the pinhole board. The pinhole is about f/256. Test pictures to follow shortly...
--Dave
I was working with 36 AWG brass foil from A. C. Moore. From here, on, I followed rather closely these instructions from Silverbased. I did a few practice holes in scraps of aluminum sheet metal that I had lying about, then went to the brass. The only sphere I could find was from the end of a pull-chain on a lamp. Borrowing it, I hammered a dimple into the foil:
Then with 400 grit sandpaper, I sanded the back ("outie") side of the dimple until it was flat and in fact somehow got a sub-dimple that went the reverse way:
Turning the foil back over, I then pricked it with a sewing needle (yeah, a needlehole, not a literal pinhole):
The Silverbased instructions suggest not going all the way through with the needle, but rather making a needle-end-shaped even tinier dimple, then sanding off the end of the that to make a hole. My needle went through, though. I then flipped the foil over, sanded any shards off the back, cleaned the foil of shavings/dust, and went to my scanner. I covered all edges of the foil with paper to avoid scratching the scanner glass:
Scanning at 4800 dpi, measuring the hole in pixels, and doing the math, I found the hole was about 0.16 mm in diameter(!!!):
This is less than half the 0.45 - 0.50 mm size that Mr. Pinhole recommended for 4x5 at about 125 mm focal length (i.e., with the standard as far back as it goes). So back to the beginning of the brass -- hammer -- needle process. Next one was 0.45 mm -- spot on:
I cut the brass to about 4 x 5 cm around each hole, chamfered the corners to stop them snagging on things, and sanded the edges to remove any burrs:
I cut a hole at the center of the lens board with a Forstner bit that I happened to have:
Regrettably it minced the face of the final lens board a bit, after of course having cut cleanly on some practice holes that I did in junk board. Anyway I affixed the pinhole plate to the back of the lens board with electrical tape. (Use gaffer's tape if you have it.) --
I centered the pinhole in the lens board by eye. Theoretically, you should very perfectly center it somehow. I think it's close enough:
And I labeled the pinhole as to diameter lest I confuse myself ("which one is this?!") in future. Finally, here is the finished Speedhole! --
I sized it to work at the stops for the 135 mm Optar. This means it will have about the same FOV as the Optar, so if I want to I can compose on the ground glass using the Optar, then swap in the pinhole board. The pinhole is about f/256. Test pictures to follow shortly...
--Dave
Argenticien
Dave
I did test shots on Delta 100 Pro in hazy sun. My iPhone metering app metered 16 sec at f/256. I had the Delta 100 Pro data sheet open, which suggested that I needed to correct to 60 sec for reciprocity failure, which I did. I shot another at 30 sec just to bracket it a bit. Both exposures look the same. The sun was ducking in and out of clouds; maybe it did so differently during the two exposures and netted out my 1-stop difference.
Developing was in a two-35mm-reel faux-Paterson tank (Freestyle Arista knock-off) with film loaded in the "taco method." This is getting silly; I need to get a MOD54 setup. Rodinal 1:50 for 14 min at 20 C.
0.45 mm pinhole (about f/256), 30 sec:
For comparison, Optar 135/4.7 @ f/32, 1/4 sec (-ish; my slow speeds don't work, so the "1/4 sec" was guesstimated using Bulb setting).
I suspect the dark bands at the top of the pinhole frame (and which were atop 2 other frames) may be related to my janky taco-method developing.
Anyway, as pinholes go, this appears to be pretty damn sharp and have full coverage of 4x5. This could be the beginning of some fun...
--Dave
Developing was in a two-35mm-reel faux-Paterson tank (Freestyle Arista knock-off) with film loaded in the "taco method." This is getting silly; I need to get a MOD54 setup. Rodinal 1:50 for 14 min at 20 C.
0.45 mm pinhole (about f/256), 30 sec:
For comparison, Optar 135/4.7 @ f/32, 1/4 sec (-ish; my slow speeds don't work, so the "1/4 sec" was guesstimated using Bulb setting).
I suspect the dark bands at the top of the pinhole frame (and which were atop 2 other frames) may be related to my janky taco-method developing.
Anyway, as pinholes go, this appears to be pretty damn sharp and have full coverage of 4x5. This could be the beginning of some fun...
--Dave
f16sunshine
Moderator
Nice Tutorial Dave. You didn't skip a beat.
Interested to see how your images evolve with your new "lens".
Interested to see how your images evolve with your new "lens".
leica M2 fan
Veteran
Nice going Dave. Be sure to post other results when you have them. Nice work on this
project.
project.
Argenticien
Dave
Thanks gents. Worst case I'll get out with it again for WPPD on the 27th, if not earlier.
--Dave
--Dave
vdonovan
Vince Donovan
Really nice tutorial, and looks like you are getting great shots!
I agree about the taco method. I did a few sheets that way and got very inconsistent results. Finally got a MOD54 and I absolutely love it, I've been getting great negatives.
I agree about the taco method. I did a few sheets that way and got very inconsistent results. Finally got a MOD54 and I absolutely love it, I've been getting great negatives.