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Re: paleonet Digital photography again



At 12:58 AM +0200 10/25/01, Stefan Bengtson wrote:



>But all this is about lenses and microscopes, not about the way the 
>images are captured. There is no question that you can take great 
>pictures on film - or on CCD chips. I've been using the same Micro 
>Nikkor macro lens on a 35-mm camera and on a digital camera 
>(MicroLumina): the digital images are generally better, as they have 
>not been filtered through the grain of the film and the subsequent 
>scanner.


Not to quibble, but it's about attaching lenses to cameras.  If it is 
genuinely possible to adapt a digital camera body with sufficient 
pixel resolution to my Aristophot, I'll mothball my film scanner in 
an instant.  The system uses a Leica 35 mm camera body.


>>Granted, people will often swear by the lens they have been using 
>>for decades, and then tragedy ensues when it doesn't fit any of the 
>>new digital cameras.

Yes, but there's a reason for that and it's not necessarily because 
they're dogmatically attached to old equipment that they know.  Doing 
the best photography with small specimens in paleontology is 
something that a lot of effort has been poured into over the decades. 
There's a reason the Aristophot system is still in such widespread 
use, despite being a virtual antique, and there's a reason Nikon 
found it profitable to make an imitation of it (for a while).  Not to 
disagree with anyone whose results I after all haven't seen, but 
these systems are vastly superior to any results I've seen with 
microscopes (again, depth of field with convex fossils is the key 
problem).  It's a niche/fringe concern in general photographic 
circles, but light photography of mm-scale fossils remains a sticking 
point.  If someone built a digital system that emulated the optics 
and lens quality of an Aristophot, I'd buy it.  And if it's possible 
to couple a digital camera with sufficient pixel resolution to an 
Aristophot, I want to do it.  My point is that while this size range 
is perhaps of niche interest, quite a lot of fossils fall into it, 
and only a few specialized lenses have ever been produced that give 
really high quality results.

>
>>   And, for people in this boat, resolution continues to be an 
>>issue. With 4000 dpi negative scanning, you get 5512x3675 pixel 
>>resolution of a 35 mm frame.
>
>But again, do you need that resolution? Accepting the 300 dpi 
>resolution as standard for good print, you could blow up your hi-res 
>35 mm negative to more than 18" width...


As I said in an earlier post, 450 dpi is the standard at least for 
Journal of Paleontology, which is printed with a 300 lpi screen (I 
certainly agree that once the world moves decisively away from 
printed journals [soon], 300 dpi is an adequate norm).  Granted, 12" 
is still a big trilobite (though you'd need to completely fill the 
frame to get it).  The biggest enlargement I make with my workaday 
photos is x5.58 (since the frame is far from filled, the trilobite is 
a very modest 1.5-2"), which is less than the maximum possible with 
4000 dpi scanning (x8.89).  So I could get by with a 2700 dpi 
scanner.  But for digital cameras, even the Fuji S1 Pro you mention 
isn't there in terms of resolution (3042x2016 on a 2" LCD, allowing 
an equivalent maximum of x3.38).  Now actually, that would be okay 
for quite a lot of what I do, but only just, in a range of cameras 
that retail from US$3000 to US$5500.  Assuming 300 dpi it would be 
fine (and many print journals do request only 300 dpi).

Yes, I don't think we disagree much.  You think we're perhaps just 
past getting there, from the perspective of micro/macro photography I 
think we're perhaps nearly there.

J
________________________________________________________
Jonathan Adrain                 Managing Editor
Assistant Professor             Journal of Paleontology
Department of Geoscience
121 Trowbridge Hall             phone (319) 335-1539
University of Iowa              fax   (319) 335-1821
Iowa City, IA 52242
USA

http://www.geology.uiowa.edu/faculty/adrain/adrain.html
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