First trip with my 8x20 pinhole
Built an 8x20 pinhole over the Christmas break, just did my first trip with it. I'm thrilled with the results, the 'big box' worked perfectly.
It's a 300 mm focal length with a .650 mm laser drilled pinhole, giving f/450(ish). I use f/512 for exposure calculations. FOV is about the same as a 20mm lens on 35mm film. A nice wide panorama.
I built an 8x20 sheet film holder from black foam core, mat board and duct tape. The camera is built like a big shoe box sort of. The film holder goes in (sits on a lip inside the box) and lid fits over, to seal the light.
My shutter is an old wooden Montecristo Cuban cigar box, (which is suprisingly well made). Open to expose, close to end the exposure.
I'm surprised at how sharp the results were. Good resolution and very little fall off. (The thing is almost too good; I was hoping for a little 'pinhole funk' . . .
Film is Efke 100, developed in HC110, Dil H, for 14 minutes. My plan is to contact print the negs as VDBs and albumen prints. Maybe even some bromoil.
That, my friend, is one big camera!
Originally Posted by Mark Fisher
It does take a nice picture for sure. How long was the exposure?
This exposure was five minutes. I've worked out a table that shows for the most part, exposures should be between 1min 30secs and 60 mins, figuring for reciprocity.
My G10 (which I use for my meter) metered this scene at ISO100 at 1/100@f/8. That translates to five minutes on my pinhole, reciprocity factored in. The worst case scenario, from what I can tell, will be if the G10 says the scene is 1/15@f/8. That equals 60 mins on the pinhole.
If it's darker than that I probably won't shoot, as a 60-minute exposure is probably all my patience will be able to endure.
That must be the ultimate camera obscura, an humungous 8x20, and it looks very well engineered, too! I do like the ultra-wide view and definition does appear good (assuming no sharpness has been applied by Photochopping!). I agree with your comment regarding a perceived lack of "pinhole funk" (there goes a term with clout!); I don't want my pinhole images to exhibit the razor sharpness of my Canon L-series optics!
I will shortly be changing the format in my Zero Image from 6x6 to the "ultra-wide enough for me" 6x9.
Efke sounds like an interesing film in the old classic mould, but my Pro lab was unaware of the need for a hardener to be applied (or somesuch) due to its perceived "frailty".
Last edited by Poisson Du Jour; 01-10-2010 at 05:08 PM. Click to view previous post history.
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No sharpening at all, just Levels adjusted. I had to scan the neg in two parts on my Epson V700, however, and reassemble the image in PS.
My plan is to contact print these, as soon as I update my UV printing system to print the bigger negs.
And the pinhole is not as sharp as a Canon L, for sure; there's some softness. I think I might pick up a zone plate or sieve to try out as well. And perhaps I'll get more pinholeishness with more direct 'in-the'lens' kind of light. Things to play with.
If not, I built a dirt cheap LF 8x20 camera . . .
Here's a link to the 100 per cent size, raw scan of the neg. It's not the best scan, just a quick rough one to get it digital . . .
Last edited by Kami-the-Trout; 01-10-2010 at 05:33 PM. Click to view previous post history.
Wherever you are, it looks bloody cold too (USA?), which is in stark contrast to the 43°c heat being experienced in Victoria, Australia at this moment — quote torrid indeed...
A Zone Plate will make your image extremely soft and indistinct (I had and still have the option of a ZP on my Zero Image); it's a much more 'abstract' interpolation of the scene before the pinhole than what you have, but still ideal for a try to compare the two styles. I personally have no wish for any degree of sharpness in my pinhole images (as opposed to definition ); very happy with all the effects, just need my car back from the repairer to continue the work so rudely interrupted on 13th December by a bingle...
Good point on sharpness versus definition . . .
As far as temp up here (I'm in B.C., Canada), the temp this past week has been about -2C — pretty darned livable for winter here actually. It was -22C before Christmas. Now, 43C is just plain nasty, although we hit 40C here in our summer as well, which is your winter, of course.
And what the heck is a bingle?
If you want less sharp, just use a less optimum pinhole. I've only made a couple of pinhole cameras, but I noticed that my home-made pinhole (pop can, needle and sandpaper to make pinhole) was much less sharp than a laser cut pinhole with approximately the same pinhole size. You could also use a larger or smaller pinhole.
Originally Posted by Kami-the-Trout
Sorry, a bingle to us in Australia is an accident in the car—usually a minor one (though this "minor" one has put my car off the road for a month!!)
On 13/12 I was distracted in heavy rain by two red signs advising oh-so-politely of bushwalkers using the road I was on also, then before I know it instead of following the road as it curved, I went up the embankment! Didn't even know I'd hit it until the mud stopped flying...