Fun Challenge for those that fancy it.

[andy153]

Thanks Sassan - I know what you mean - you only have to look at the price of the new digital H series Hasselblads to get some idea. The full H3 rig costs about £30,000 over here last time I looked and that's no where near 6"x4".

[mw_aurora]

Originally Posted by sassan

Looking at the size of pinholes I guess this either from a Giant land Pins or these are nailholes

0.25mm big??? I think you are seeing the hole he covers with a very thin material to make the actual pinhole.

[Don Hoey]

Originally Posted by sassan

Looking at the size of pinholes I guess this either from a Giant land Pins or these are nailholes

Sassan,

From what I have read the pinhole should be in as thin a material as possible. For max sharpness it should be as close to perfectly round and there be no burrs. I guess in this case the caps only act as a carrier for the fine material containing the pinhole.

I will test the theory, but I do not want to shell out for any special focus sharpening progs. Of course I could always post a large image here for you photoshop gurus to play with.

Don

[Don Hoey]

I have been thinking softness in pinhole photography will be greatly affected by diffraction limits of the sensor. I have posted a test somewhere that shows this effect and my conclusion was f13 is the D2X limit before the effect starts to show. So a pinhole giving an aperture of around f200 is really challenging that, and cannot expect too much in the way of sharpness at all.

I have just found this link which looks interesting.
http://galactinus.net/vilva/pinhole/index.html

If you scroll down to ' The Retro Way : My Other Photography ' then this guy has tried out more alternatives than I have.

Don

[sassan]

Originally Posted by Don Hoey

I have been thinking softness in pinhole photography will be greatly affected by diffraction limits of the sensor.


I have just found this link which looks interesting.
http://galactinus.net/vilva/pinhole/index.html

If you scroll down to ' The Retro Way : My Other Photography ' then this guy has tried out more alternatives than I have.

Don

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.

That was a nice link Don. Loved the L class lens on 350D Canon only the red L colar is too obvious and a bit backwardly placed

[yelvertoft]

Originally Posted by Don Hoey

To go with the BBC 4 tv series thread, on the cheap create an image that has the feel of an old picture. Duncan has of course already started with this
http://www.worldphotographyforum.com...ppuser=34&sl=y

It wasn't my intention to make this picture look old, I was aiming for an authentic B&W film feel rather than an historical record of a bygone scene. Not sure how long pedallos have been around, but I dare say it's not very long ago.

Nevertheless, you lot all seem to be having fun, so I thought I'd have a go at the intended theme. This is my real attempt to get a digitally produced image looking like it came out of an old shoe box in an elderly relative's attic.

D.

[Don Hoey]

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.

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

[Don Hoey]

Originally Posted by yelvertoft

It wasn't my intention to make this picture look old, I was aiming for an authentic B&W film feel rather than an historical record of a bygone scene. Not sure how long pedallos have been around, but I dare say it's not very long ago.

Nevertheless, you lot all seem to be having fun, so I thought I'd have a go at the intended theme. This is my real attempt to get a digitally produced image looking like it came out of an old shoe box in an elderly relative's attic.

D.

Duncan,

I wondered how long before you joined in.

Don

[Don Hoey]

This thread has me playing around in photoshop.

Following from Sassans gallery IR pics I thought I would have a go at trying it in photoshop so this is not shot in IR. Luckily AP had an article on this a couple of weeks ago or I would not have stood a chance.

So a bit of a more modern look, but for those that ever had a play with Kodak High Speed Infrared film this may strike a chord.

Don

[sassan]

Don:

Very nice go both on pinhole and then IR.
One thing I can say for sure is you have invented an inexpensive way to check sensor cleanness when buying a use DSLR

Now all I like to see more is your go on Photoshop. Its really fun an easy the only tricky thing with photoshop is they didn't put up their icons in right spot; As long as you start with "Image" from tool bar, try all three listed Auto-Things, then, from same menu, reduce the size to say 800 pixel and lastly from "Filter" menus use the USM (UnSharp Mask) and play with parameters, you have made that giant leap. If you have already done this, you are ready to check the non auto version of same choices then exploring every option under "Image" attention to "curve", "highlight and shadows" "Hue and saturation". Next is to change the canvas size from same menu. To let real fun begins, you may want to go through the "Artistic filters" under "Filter" toolbar. And the next step to discover the power of Layers. This is where real fun begins and next sky is the limit.

You definitely don't have any noise as I thought should be a problem. Sorry if your flash got smoked but for a fact I know those repetitive bust flashes are fun to make (You remembered how I smoked my 30D's circuit twice that way on 5fps and BTW Canon repaired the second time for free). I am wondering why the sharpness is not any better. Was the pin too thick? 0.3cm look that way to me but then for indoor light it sure was a good choice. Or may be your distance form sensor was too close.
I know some good result are achieved by exposure of upto an hours or so but of course talking of old film manual cameras. Don't know if DSLR's batter can coupe for such a long exposure in first place (From sensor cleaning experience I am sure they can't. BTW my suggestion for any one who is planning to use a very long exposure don't know how or doesn't have an external lockable remote shutter release, is to use this sensor cleaning feature that basically keeps your mirror locked up with curtain open for as lone as main switch is turned to off or battery is completely drained.

I promise to give a go on this pinhole, this weekend. You see week days are hard to get back home on time, before sun is up and then with Halloween that is at its dawn (With being interrupted at least a 50 times since started this short paragraph by spooky creatures at the door who are here for treat or treats {Wrongly called treat or trick}) there should be more time this weekend.