Author Topic: Digital Photography (Read 842 times)

-dead- · « **Reply #15 on:** January 09, 2003, 04:55:26 AM »

Quote

Originally posted by whgates3
the best 35mm film has grain sizes as small as 0.3 µm (.0003mm).
not coinidentally, 0.3 µm, is the shortest wavelength visible to the human eye, so you dont get better than that as far as image resolution goes unless you're working on a UV or X-ray camera.
the size of a 35mm negative is ~ 36mm x 24mm - thats nearly 10 billion 'pixels' @ 0.3 µm² per pixel...& 3 bytes per pixel (24 bit color is pretty standard)...so this is going to produce images larger than 30 gigs per...not that i'm saying this couldn't be a serious advance - the same type of gnarly films (double digit ASA stuff) i used as an example are sensitive to about 1 in 10,000 photons that hit it. the best CCDs can be sensetive to better than 9 of every 10, but have pixel sizes in the range of 10 µm per pixel and are much smaller than 35mm negative. combine CCD sensetivity w/ film resolution & a big arnold hard drive & you have just about a perfect imaging system

35mm film gets pretty damn grainy once you take it up to A4 size - depending on lighting and that. Which is why there's bigger formats...

The Sigma's pics look a damn sight better than any digital camera pics I've seen so far.

More importantly for print production, it actually separates like it's a drum-scanned picture, whereas the average digital pics produce far more dodgy-looking JPEG artifact kind of plates. Digital pics generally have either that "TV picture" look and/or lack the tonal contrast of film too.
Now all they need to do is double the resolution of 2268x1512 and I'd definitely buy one... fairly tempted now - reckon you could push the pics up to near A4 - which is amazing - generally digital pics should only be pushed down. Or given back with a scathing look.

LePaul · « **Reply #16 on:** January 09, 2003, 09:18:27 AM »

I have 2 cameras... a Cannon AE-1 35mm with many cool addons, zoom lenses, filters, tripod, etc. My other camera is a Sony Mavica...dont recall the model, writes images to a floppy in JPG format but has under 1m megapixel...its about 2 years old.

If I could find a digital camera that had the convenience of writing to media (not flash ram), and could offer me the addons and gizmos my AE-1 can support..bigger zoom lenses, etc...then tell me where it is, I wanna make an offer!

The Cannon I have doesnt have autofocus, so it was of little use to me when flying. But for more serious photo-taking, and the fact I could link it on via an adaptor to my telescope, I got some killer pics of the moon and planets.

whgates3 · « **Reply #17 on:** January 09, 2003, 12:34:19 PM »

Quote

Originally posted by -dead-
35mm film gets pretty damn grainy once you take it up to A4 size - depending on lighting and that. Which is why there's bigger formats...

The Sigma's pics look a damn sight better than any digital camera pics I've seen so far. More importantly for print production, it actually separates like it's a drum-scanned picture, whereas the average digital pics produce far more dodgy-looking JPEG artifact kind of plates. Digital pics generally have either that "TV picture" look and/or lack the tonal contrast of film too.
Now all they need to do is double the resolution of 2268x1512 and I'd definitely buy one... fairly tempted now - reckon you could push the pics up to near A4 - which is amazing - generally digital pics should only be pushed down. Or given back with a scathing look.

i worked once w/ a 66 megapixel CCD - damned good, but still not near the total resolution (total number of pixels) of a 35mm negative, even though the CCD itself was 3"×4" - of course if you want to shoot a detail in good resolution, just use a long enough lens or get closer to the target. digital is certainly (in the long run) cheaper & any problems you have about the look of the image (contrast, etc) can be fixed in photoshop or whatever you use. if you want to make a large print you need a lot of dots to fill in the space or it will look cr@ppy - even 4500 x 3000 contains only the amount of information on ~ 1.5 mm² of chemical film (less than 0.2% of a 35mm negative). mosaics of CCDs could compete w/ film maybe

-dead- · « **Reply #18 on:** January 09, 2003, 01:43:23 PM »

Quote

Originally posted by whgates3
i worked once w/ a 66 megapixel CCD - damned good, but still not near the total resolution (total number of pixels) of a 35mm negative, even though the CCD itself was 3"×4" - of course if you want to shoot a detail in good resolution, just use a long enough lens or get closer to the target. digital is certainly (in the long run) cheaper & any problems you have about the look of the image (contrast, etc) can be fixed in photoshop or whatever you use. if you want to make a large print you need a lot of dots to fill in the space or it will look cr@ppy - even 4500 x 3000 contains only the amount of information on ~ 1.5 mm² of chemical film (less than 0.2% of a 35mm negative). mosaics of CCDs could compete w/ film maybe

As far as Digital files go 2976 x 4175 pixels [216mm x 303mm @ 350 dpi] is all you'd ever need for A4 CMYK printing of a photo @ 175lpi, (although for text/line art you have to go much higher- (10205 x 14315 [216mm x 303mm @ 1200dpi] for preference). The final film is output @ 2450 dpi for smooth text (text and line art are usually taken care of by postscript to avoid enormous files). But 35 mm film can't always hack that sort of enlargement - 500 times the information (an absolutely best case scenario I reckon) or not.
For example, here's a cropped bit of a 35mm slide that's been blown up to A4 - fairly grainy, I reckon:

Dinger · « **Reply #19 on:** January 09, 2003, 02:12:52 PM »

check out the review of the D9 over at dpreview.com . Oh and look at the message boards too.
Looks like what you'd expect from a first-generation offering: bugs in the hardware and bugs in the software.
Still, give it a couple of years....

Dnil · « **Reply #20 on:** January 09, 2003, 02:35:00 PM »

what film speed is that blow up dead?

Nikon, canon and another company all make digital slrs now. the nikon is pretty badass and under 2k. It uses all the nikor lenses of regular slr cameras and looks a lot like the n90 series.

I own a 4meg pix kodak, 2 canon a-1s, pentax all manual spotmatic for backup and an nikon n70 for normal shooting.

whgates3 · « **Reply #21 on:** January 09, 2003, 03:30:47 PM »

ja, 0.3 µm is the aboslute best cast scenario for any visible light imaging situation, as 0.3 µm is the shortest wavelength visible to the human eye. film can achieve it & no digital detector can, but with a standard imaging situation you dont achieve that because if the limitations of the lens - a 50mm lens produces an image that is ~ 4125 arcseconds/mm (about 1 arcsecond per 0.3 µm - 50mm standard lens is not that size by accident) @the focal plane, but the lens at standard f/ratios (i.e above 2.8) has a theorectical limit of more than 5 arcseconds for the smallest resolvable detail - even@f/1, two arcseconds is the best you could do, because of the ratio of the objective lens diameter to the frequencies of the light involved...it's not until you use lenses that are larger than 100mm objective diameter (something like a 300mm f/2.8 lens) that you can achieve the maximum amount of detail possible...film doesn't transfer well to grid style printing as silver halide grains are not square

Wlfgng · « **Reply #22 on:** January 09, 2003, 04:05:47 PM »

fwiw I was referring to broadcast cameras not photo cameras.
big difference due to the presentation medium (TV)

film is still far better in terms of clarity.
But the fact that thre'll be no CCD's in our TV cams is huge.
smaller, cheaper, etc

Nath[BDP] · « **Reply #23 on:** January 09, 2003, 04:47:58 PM »

It's the pilot not the plane. ;p

whgates3 · « **Reply #24 on:** January 09, 2003, 08:30:18 PM »

i dont know about the new stuff, but the cooling issues w/ CCDs can be a pain in the arnold. how are good TV CCD cameras cooled? TE or chemical or otherwise?
cant believe someone hauled an IMAX camera up Mt Everest...sherpas R00L!

-dead- · « **Reply #25 on:** January 10, 2003, 02:06:55 AM »

Quote

Originally posted by Dnil
what film speed is that blow up dead?

Nikon, canon and another company all make digital slrs now. the nikon is pretty badass and under 2k. It uses all the nikor lenses of regular slr cameras and looks a lot like the n90 series.

I own a 4meg pix kodak, 2 canon a-1s, pentax all manual spotmatic for backup and an nikon n70 for normal shooting.

It says FUJI RA on the tranny's edge, so I presume it's Fuji RA Sensia @ 100 ASA - but I haven't a clue about what shutter speed, lens or F-stop the guy took it with.

whg3: it's not grid style printing, it's offset - the dots printed aren't square either - got a choice of round, diamond or eliptical

All four sets of dots are at different angles too - that's how the trick works.
I'm not really sure because I have very little clue about film theory - but I fear that for film to be useful - ie capture stuff that's alive/moving - the actual resolution is nowhere near as good as the theoretical maximum.
I'm just working from my everyday experience - not as a photographer but as a graphic designer:- 35mm is not very good stretched to A4 size because it looks grainy. Hardly surprising to my mind as it's almost 1000% of the original size. Medium format is much safer. Digital is extremely dodgy. So in order of preference for A4 it'd be medium format, 35 mm, digital (although it'd probably have to be at least 5 megapixels before I even bothered to consider it). So film's definitely the best so far - but as far as I've seen in real life applications, the results are not nearly as brilliant as you suggest. But the new Foveon CCD looks promising - certainly the first digital pics that don't look like digital pics.