Go Back   Steve's Digicams Forums > Digicam Help > General Discussion

Reply
 
Thread Tools Search this Thread
Old Jan 16, 2003, 1:08 PM   #11
Senior Member
 
Join Date: Jun 2002
Location: Victoria, B.C., Canada
Posts: 938
Default

This is fascinating!

As I said, I'm mathematically challenged.

Does it amount to this - that if I've taken my picture of the duck with my Olympus using it set on 10x zoom, the only way I could get an equivalent picture of the duck on it's nest with the Olympus zoom set at zero would be if I could transform the Olympus 2 megapixel sensor into one that recorded 200 megapixels?
Herb is offline   Reply With Quote
Old Jan 16, 2003, 2:25 PM   #12
Senior Member
 
Join Date: Aug 2002
Posts: 2,162
Default

For the mathematically challenged - at 0 mag, let height=h and width=w. approx pixels for 300 dpi print would be 300hX300w. = 90,000hw where h and w is the output print image size in inches.

Now magify this image 10 times. New image size = 3000hX3000w= 9Mpix.h.w

In the meantime the duck has probably flown away, so it was all a bit academic.

So the guy shooting with the big high quality tele. and tripod with the 2Mpix cam gets the good 6x4 print, actually he pops off a dozen shots and has some choice, whereas the other chap at the same distance with a fixed lens and a 2Mpix cam , gets a load of mush in PS that he can't do much with! Another guy with a hypothetical 200Mpix cam who can't afford the zoom, only takes 1 pic, which fills his memory card. When he got back to edit and crop the shot, which he couldn't do on the lcd, the duck had moved and was out of focus!

Which is why wild life photographers (who may not wish to get eaten by their subjects) choose long fast lenses, preferably with image stab. and a tripod!
voxmagna is offline   Reply With Quote
Old Jan 16, 2003, 3:01 PM   #13
lg
Senior Member
 
Join Date: Jun 2002
Posts: 823
Default

If no one else appreciates your colorful explanation, voxmagna, I do! One attaboy for you! :lol:
lg is offline   Reply With Quote
Old Jan 16, 2003, 4:33 PM   #14
Senior Member
 
Join Date: Jan 2003
Posts: 436
Default

What you are looking for is the "Figure of Merit" which is a way of calulating the relative power of an optical zoom versus a high resolution CCD. You can find a technical explanation at:

http://www.mav-magazine.com/Jun2000/FigureofMerit/
Meryl Arbing is offline   Reply With Quote
Old Jan 16, 2003, 5:12 PM   #15
Senior Member
 
Join Date: Aug 2002
Posts: 2,162
Default

That's an interesting link for the mathematically challenged. The conclusions one draws from the table ranking different cam sensor res. zoom mag. and preceding info, for the mathematically unchallenged is:

Factor of Merit is determined mainly by the square of the optical focal length, and looking down the table, lens zoom is the main factor determining the FOM. and not sensor res. which is what you'd feel is right, because you'd need a big change in sensor res. to make any difference to the FL squared factor.

So big glass wins then at the moment? That duck is sure to get in the picture!
voxmagna is offline   Reply With Quote
Old Jan 16, 2003, 5:27 PM   #16
Senior Member
 
Join Date: Jan 2003
Posts: 436
Default

Yes, the camera list is a bit out of date but the math is simple enough to allow a quick spreadsheet to be built with current camera specs.
Meryl Arbing is offline   Reply With Quote
Old Jan 16, 2003, 5:35 PM   #17
Senior Member
 
Join Date: Jun 2002
Location: Victoria, B.C., Canada
Posts: 938
Default

Vox mathematicae. vox dei, eh? My attempt to attempt to follow these ascents into the ethereal realms of higher mathematics did, (as the article cited by Meryl, described it), send me to the medicine cabinet - from which I've just returned.

I think I'll just soldier on with my Olympus C2100UZ and wait until somebody manufactures a camera that combines a Foveon sensor with lots of zoom......& that I can afford & that Steve recommends.......
Herb is offline   Reply With Quote
Old Jan 16, 2003, 6:10 PM   #18
lg
Senior Member
 
Join Date: Jun 2002
Posts: 823
Default

Meryl, thanks for the reference to the FM article and chart! It was very informative and quite enlightening.
lg is offline   Reply With Quote
Old Jan 16, 2003, 7:08 PM   #19
Senior Member
 
Join Date: Oct 2002
Posts: 544
Default

Makes us Canon Powershot Pro90 owners proud! This camera has been terrific for me, tho' I must admit a few more pixels would be nice. The camera has a great 10X stabilized lens (same one used by Olympus in their 2100UZ and 100RS) and a 2.6 megapixel effective sensor.
Wildman is offline   Reply With Quote
Old Jan 16, 2003, 9:00 PM   #20
Junior Member
 
Join Date: Dec 2002
Posts: 24
Default

Thank you Johnny. I did not think it had been that long. But I never did resign up when they changed formats for the forums. Then I died and was not around for awhile.

These kind of discussions are fun. Just so no one takes them seriously and buys a camera based on them. I am not trading in my C2100. However, the CP5700 cropped to 2mp (1600X1200) to match the resolution of the C2100 gives an equivalent photo of 448 versus the 380 of the C2100. But, the IS is of value. The B-300 is also (as is the B-Macro). I also like the size and feel of the camera and the focus assist. There is more than 10X involved. BTW, the 10X is sometimes meaningless without starting and ending points of the zoom ratio. The 7X of a dimage 7 at 28 to 200mm is very different from a 7x that goes from 50 to 350mm.

Now when someone comes out wiht a 11.1 mp camera with a 28 to 300 zoom, we will have something to talk about. Wooops, Canon did do that. But no one has bought me one. And I do not know anyone buying it who has gotten that lens for it. BTW, the 1D was said to be 1.3X. And the 1Ds is said to be 1:1. This is as compared to 35mm with the same lens. If you crop the 1Ds to 1D resolution, it shows a much narrower field of view (more magnification) which would make it closer to 1.6X. Not bad for a 1:1 camera. As the density of the sensors increase, and the size of the sensors increase, we will have many more numbers to play with. Of course all of this goes beyond the limited question which started the discussion. But then if you examine the question, it was if you have two photos the same resolution showing the same subject at the same size, which is better. Which only makes any difference if there is something to effect the quality of the 2 photos.
DeMorcan is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 12:07 PM.