Quote:
Originally Posted by sassan
I thought the only problem with long exposure of pinhole and digital sensor should be the excess noise that you also get in long exposed deep sky images (Those unwanted mostly bright and dark red spots similar to pixel dead on monitor). I sincerely hope to find some time to do my own exploration in this interesting field.
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Sassan,
Specially for you I have had another go at pinhole photography this evening.
I made a 0.3mm ( very fine sewing needle ) hole in a piece of shim. Shim was attatched inside a body cap suitably drilled. I found info that suggests the aperture for this is f229. D2X diffraction limit has been tested by me, and the image gradually goes soft from f13 so I am not too surprised by what I see here.
I tried the pin hole body cap direct on the body but found plus 50mm of tubes gave a sharper result. Exposure under the workshop lights with some assistance from flash was 20 secs at ISO400. Not sure the Multiblitz flash enjoyed being rapidly fired manually during that as it started smoking.
3 pics attatched.
1) The effect of such a small aperture on sensor dirt. This is a 100% crop. Foxy would have had a nightmare at leaving everything open to crud but at least it shows the effect.
2) A resized image with no sharpening or focus correction.
3) A larger version in case anyone fancies a go at it.
Don