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Re: Digital vs. film SLRs   Message List  
Reply | Forward Message #27430 of 53097 |
Re: Digital vs. Film SLRs -- "The Photos have arrived...!!!" ?

Merv (and All),

Sections of the first "Red vs White Light" test photos are now
available, as either ".tif" (800K file) or ".jpg" (100K file):

http://microbooks2000.tripod.com/testing/C2040Za.jpg

http://microbooks2000.tripod.com/testing/C2040Za.tif


The .tif is uncompressed and therefore more accurate, but the .jpg is
very close, will load much faster, and can normally be viewed online,
directly in your browser window (Netscape/IE, etc.).

Viewing at larger scale, so as to make the individual pixels visible,
is recommended for making comparisons.

IE users may want to try "Zoom-In" for viewing the .jpg, or download &
save the .tif to view in their image editor.

The two "20/20" sets are most revealing...

Hope this helps clarify the issues!

Dave J.


********************************

--- In Microscope@yahoogroups.com, "mervhob" <merv.hobden@n...> wrote:
>
> David,
> That is a first class suggestion and fits exactly with the known
> facts. I should have done that before I hacked out the lens from the
> DC440! The ordinary photographic results with it were first class...
>
> Waaaaaaah!
>
> Merv
>






Sun Nov 13, 2005 1:11 am

djacksonnj
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Forward
Message #27430 of 53097 |
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Merv, I am repeating this (from message 27459) because I think you may have missed it :- ... So, did you get strange colours ? ... The shutter is not too bad...
David Sykes
microfunguy
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Nov 15, 2005
1:29 pm

Merv (and All), Sections of the first "Red vs White Light" test photos are now available, as either ".tif" (800K file) or ".jpg" (100K file): ...
David Jackson
djacksonnj
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Nov 13, 2005
1:12 am

... so can Mozilla Firefox users ! I just zoomed 400%. David Sykes...
David Sykes
microfunguy
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Nov 13, 2005
1:41 am

... Dave, See http://tinyurl.com/cb8m4 (http://www.janrik.net/MiscSubj/CanonDigitalRebelColorResolution/Canon D300ColorResolution.html). These are results for...
Rik Littlefield
rjlittlefield
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Nov 13, 2005
6:25 am

Rik, Very nice work -- thanks for your input! However, I checking the actual response of various Green filters I find that All of them, to some extent pass...
David Jackson
djacksonnj
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Nov 13, 2005
7:55 am

... http://groups.yahoo.com/group/Microscope/message/27446 "David ... Dave, I reworked my web page at http://tinyurl.com/cb8m4 to answer some of the questions...
Rik Littlefield
rjlittlefield
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Nov 13, 2005
6:20 pm

... Dave, I have new data that tells a very different story. I did some more investigating and discovered that dcraw already has a -d parameter that seems to...
Rik Littlefield
rjlittlefield
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Nov 19, 2005
6:14 am

Rik, These effects seem to exist in your posted images (Red and Blue) but you need to zoom-in more so that you can clearly see the individual pixels. The IE...
David Jackson
djacksonnj
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Nov 13, 2005
8:22 am

... Dave, I disagree, but I can understand how you got that impression. In the web page that you looked at, all of the images were supposed to been scaled up...
Rik Littlefield
rjlittlefield
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Nov 13, 2005
6:34 pm

Rik, Thanks for the update. I will try to hunt down a newer, better camera and repeat the tests to see if the same effects re-occur. It would seem that they...
David Jackson
djacksonnj
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Nov 13, 2005
8:42 pm

Dave, I have been following this thread with great interest. I think this last post (and the link you provided) are very important to this discussion. While...
Charlie
sberk5
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Nov 14, 2005
12:33 am

Hi, I'm fairly new to this group, and fairly new to microscopy in general, but have found it to be a very absorbing hobby. ( ...
Jon Grove
jgroveuk
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Nov 13, 2005
10:23 am

Hi Jon, Welcome to the House of Fun! Your explanation of how the Bayer matrix is constructed fills in another piece of the jigsaw. Presumably further weighting...
mervhob
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Nov 14, 2005
12:04 am

Jon, Thank you for your very thorough discussion! However, as we seem to be drifting further and further off our original track, it may be useful to mention...
David Jackson
djacksonnj
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Nov 14, 2005
5:13 am

David, The resolution in red is alway lousy because of the wavelength of light is longer. What are you comparing the digital camera to, Kodakrome? You can find...
Gordon Couger
gordoncouger
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Nov 14, 2005
6:22 am

Gordon, Apparently you do not appreciate the value of really understanding the medium in which you are working... It is quite difficult to squeeze the BEST out...
David Jackson
djacksonnj
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Nov 15, 2005
1:52 am

David, I must agree with you, I started out with this thread not knowing a great deal about digital camera limitations. Thanks to the excellent discussion from...
mervhob
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Nov 15, 2005
1:06 pm

... The first method, to me, seems to be a terrible way to determine an approximation for a pixel value. I can't imagine anyone seriously considering using...
Dogs Afire
dogsafire
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Nov 14, 2005
3:53 pm

... Don, I think you may have read Jon's post a little too quickly. Filling in a few more words around Jon's, the explanation would be that "at each 'B'...
Rik Littlefield
rjlittlefield
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Nov 14, 2005
9:18 pm

... around ... in ... the ... Yes, that is what I meant - sorry I rambled on a bit and didn't make myself clear. The alternative method I described involves...
Jon Grove
jgroveuk
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Nov 15, 2005
4:09 pm

... <snip> ... is ... Is this what is also called a Modulation Transfer Function (MTF) filter? I've heard references to the MTF filter, but have only have a ...
Kevin
k9ev
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Nov 16, 2005
7:44 am

Jon, Rik, OK, I'm clear on the first part. I simply misread what Jon wrote. ... It still sounds as though you are attempting to derive R information from G and...
Dogs Afire
dogsafire
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Nov 15, 2005
5:10 pm

Don, The thing to be aware of is that at the G and B locations you have no measured information to tell you what R value to reconstruct so you have to make...
Jon Grove
jgroveuk
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Nov 15, 2005
5:42 pm

... But why rely on G and B channels when you have a string of R data immediately adjacent to the missing point? Why not fit a smooth function to the known...
Dogs Afire
dogsafire
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Nov 15, 2005
7:13 pm

I'm not saying you couldn't use a spline, and if you did then you would get a nice smooth interpolation - which may or may not correspond with reality. The...
Jon Grove
jgroveuk
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Nov 15, 2005
8:15 pm

My understanding of MTF (from a bit of Googling) is that it's a measure of how contrast varies with spatial frequency. The only references I came across to an...
Jon Grove
jgroveuk
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Nov 17, 2005
9:49 am
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