Pentax Pinhole cameras

Sorry Matt couldn't resist picking up on this from the sensor cleaning thread.. and I just HAVE to ask.

Are we to understand that you have converted a body cap into a pinhole lens?
What is the world coming to, state of the art digital pinhole cameras, is this another PENTAX first?

Actually I tried something similar with my OM30 some years ago, was quite pleased when I got a reliable exposure reading from the meter.

And now to give you all a laugh at my expense;
My next foray into pinhole photography was with a shoebox with an alluminium foil pinhole and using B&W paper blue-tacked to the rear.
After each exposure I would rush to the darkroom and develop the "negative" then after force drying them I tried a contact print through the paper. These turned out quite good but I was unhappy with the burned out skies, I had a quick idea which I was sure would work, I quickly loaded my "camera" up with another sheet of paper and got it into position for another exposure after removing the sticky tape lens cap I placed a red filter in front of the pinhole in order to try and darken the sky, It took several fruitless exposures before the penny dropped...DOH!

Yup

I took a body cap, drilled a hole a couple of mm in diameter in the centre, took some fine copper foil and made a fine pin hole in it then glued that over the hole.

It's not a Pentax first I'm afraid. There are plenty of resources about it on the 'net, and Katrin Eismann mentioned it in her excellent book "Photoshop Restoration and Retouching".

However, a couple of points of interest:
* Yes, it does work
* Shutter speeds tend to be achingly long
* Focus isn't that brilliant, even though DoF is huge. (One webpage mentioned that it was down to the fact you really need the pinhole closer to the sensor??)

Still, it's quite a laugh and gets some very odd results
Matt

I would guess that that's down to diffraction, and the comparatively large size of the hole (aperture) compared to the sensor. Distance to the sensor shouldn't make too much of a difference, I wouldn't have thought.

I'm thinking of when I made a pinhole camera using an old Kodak No.1A folding camera, taking the lens out (but keeping the shutter), and varying the field of view by sliding the folding bellows backwards and forwards. 'Focus' was never that good, even on 6x9 size Velvia.

Haven't tried it on my D, perhaps I will one day.

Dan

Not from Pentax but have you seen ths story?
http://news.bbc.co.uk/1/hi/technology/6263551.stm

A one pixel camera...whatever next.....

"What is so inefficient about this is that we acquire all these numbers - for example 10 million megapixels - only to throw away 80-90 percent when we do the compression process," explained Dr Baraniuk.


Where do you get one of those cameras??

Dan

You buy a Canon of course!