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10-04-2008, 03:02 PM   #16
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QuoteOriginally posted by rburgoss Quote
Full frame DSLR's with 12 to 14 mpix sensors will not give me more detail and sharpness as my K20D. The only pro is that will allow me to use my old FF glass to its full potential, but nothing more.
better viewfinder still - there are FF film cameras that have >= 0.9 magnification x 0.9 coverage and I do not see a reason why digital FF cameras can't... looks how that olympus OM-10 fares vs K10D/K20D
Standard versus Enhanced Viewfinders - Size Matters :: Wetpixel.com

10-04-2008, 03:08 PM   #17
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QuoteOriginally posted by deejjjaaaa Quote
K20D has 23.4mm x 15.6mm sensor and WPi has 5.75mm x 4.31mm sensor, the ratio is ~14:1, but
full frames from K20D and WPi (not crops w/ a piece of keychain) have ratio ~9:1
If those sensor sizes are correct, then pixel density (effective pixel count) for the WPI will be 490 pixels per mm. A lot higher than my calculations. No wonder such big diference in performance given both shots are at same focal length (aprox), same distance and same ISO setting.

Agree that smaller pixels produce higher noise and bad high ISO results, but for God's sake, in the film days, most of us will never go above 400 ASA because grain was unacceptable?

I would be perfectly happy with a 42 mpix DSLR, that can be adjusted to ISO 64 and top at 800. That would cover better my film choices that otherwise would use if still using film.

Thats it, Pentax, give us a DSLR that can match Kodachrome sharpness and Superia's dynamic range. Make it ISO 64 TO 800 just us, film era oldies can feel comfortable.

Robert B
10-04-2008, 03:11 PM   #18
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QuoteOriginally posted by Marc Sabatella Quote
Excactly! ou might not be able to tell pictures from the Optio from those of the K100D at ISO 100
it also matters is how many pixels you will deliver per steradian having the equal angle of view... so K100D should still beat Optio @ ISO100, shouldn't it ? at least because its pixels bigger
10-04-2008, 03:12 PM   #19
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QuoteOriginally posted by rburgoss Quote
If those sensor sizes are correct
took 'em from DPReview...

10-04-2008, 03:18 PM   #20
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QuoteOriginally posted by deejjjaaaa Quote
took 'em from DPReview...
Hmmmm.. that's interesting. Pentax claims the Wpi has a 1/2.5" sensor, which means a 0.4 inches diagonal (about 10 mm). By applying the Pythagoras thing, it gives me a 8.12 x 6.09 mm sensor. Anyway, in both cases, pixel density is a lot higher than on the K20D.

Robert B
10-04-2008, 03:23 PM   #21
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QuoteOriginally posted by rburgoss Quote
Hmmmm.. that's interesting. Pentax claims the Wpi has a 1/2.5" sensor, which means a 0.4 inches diagonal (about 10 mm). By applying the Pythagoras thing, it gives me a 8.12 x 6.09 mm sensor. Anyway, in both cases, pixel density is a lot higher than on the K20D.

Robert B
DPReview says

Pentax Optio WPi digital camera specifications: Digital Photography Review

1/2.5 " = (5.75 x 4.31 mm, 0.24 cm²)

http://www.dpreview.com/learn/?/Glossary/Camera_System/sensor_sizes_01.htm

10mm diagonal = between 1/1.7" and 2/3"
10-04-2008, 03:37 PM   #22
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QuoteOriginally posted by deejjjaaaa Quote
Finally, you made my point stand out with outsider words.

That same spec sheet from DpReview, claims the wpi's sensor has a 24 MP per square cm density.

Do the math with the K20D.
(23.4 x 15.6= 365.04 or 3.65 sq cms)

14.6 MP divided into 3.65 sq cm = 4.13 MP per sq cm.

Now, calculate this:
24 MP (same as Wpi) per sq cm, multiplied by 3.65 sq cms (on the K20D)= 87.6 megapixels



I really don't care if those pixels are interpolated, effective, real or whatever name they want to call them. What I do care is that the difference is very noticeable and the technology exists.

Robert B

Last edited by rburgoss; 10-04-2008 at 03:45 PM. Reason: New info
10-04-2008, 04:14 PM   #23
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QuoteOriginally posted by rburgoss Quote
Now, calculate this:
24 MP (same as Wpi) per sq cm, multiplied by 3.65 sq cms (on the K20D)= 87.6 megapixels

I really don't care if those pixels are interpolated, effective, real or whatever name they want to call them. What I do care is that the difference is very noticeable and the technology exists.

Robert B
The challenge is to have a processor fast enough to handle those 42 or 87MP. The Card fast enough to write the files, the HD big enough to store them, etc.

Now concerning noise. It has already been shown that P&S with high pixel density are actually much better than DSLR on a *per area* basis (and your test demonstrate it once again). Of course on a per pixel basis they are much worse: the pixels are smaller and collect less light, it's just pure physics.

10-04-2008, 04:26 PM   #24
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QuoteOriginally posted by Marc Sabatella Quote
On the other hand, while I keep hear we're running up against laws of physics here and you just *can't* get noise levels down much more with smaller pixels, I'm fortunately ignorant enough about the physics involved to remain hopeful that someday, we'll find a way :-)
I hope so as well but a lot of money/talent has been thrown at it for the past few years without much of a jump (the megapixel race has really put a dent into this because even Fuji dropped their F3x series' great ISO performance which is within a stop or two of the K10D to pursue the megapixel race w/ crappy ISO)-:

To me, it's like saying someone should invent an affordable lightweight 17-70/2.8 lens when the big pockets of Nikon/Canon haven't done this yet...enough people want it that it were viable, it would have been produced already...

p.s., with those test images, does the DOF of APS-C vs. P&S come into play? My guess is no, but I had to ask...
10-04-2008, 05:05 PM   #25
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QuoteOriginally posted by rburgoss Quote
Agree that smaller pixels produce higher noise and bad high ISO results, but for God's sake, in the film days, most of us will never go above 400 ASA because grain was unacceptable?
Yes, but even a poor amateur had "fast" primes, the common start set was a 28mm/2.8, a 50mm/1.8 and a 135mm/2.8. Today, instead of these primes they sell consumer zoom lenses with max apertures like 4.5 to 5.6. Try buying a short and a long constant aperture 2.8 zoom lenses! It costs! All those slow zoom lenses, that's why they need to give useful 1600ISO performance.
10-04-2008, 05:36 PM   #26
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QuoteOriginally posted by rburgoss Quote

Or could it be that the Optio has better glass than the DA 12-24... at the very center of the frame? Nahhhh.....

Robert B.
I'm afraid you have hit on the dirty little secret DSLR manufacturers never wanted us to figure out. The glass on the better P & S cameras is far superior to our beloved interchangeable lenses. Of course if they made a DSLR lens to the same optical quality it would cost an arm and a leg and probably weigh 10 pounds.
10-04-2008, 06:29 PM   #27
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QuoteOriginally posted by Douglas_of_Sweden Quote
Yes, but even a poor amateur had "fast" primes, the common start set was a 28mm/2.8, a 50mm/1.8 and a 135mm/2.8. Today, instead of these primes they sell consumer zoom lenses with max apertures like 4.5 to 5.6. Try buying a short and a long constant aperture 2.8 zoom lenses! It costs! All those slow zoom lenses, that's why they need to give useful 1600ISO performance.
You are right, but then (in the film era), no one had shake reduction. At least, Pentax claims a gain from 2 to 3 full f/stops with shake reduction. And we get that with every lens, not only special lenses from C/N.

No doubt the digital era is making us lazy. Shooting ISO 1600 is far easier than shooting ISO 400 with a consumer zoom... at f/5.6 as max aperture (long end). Of course, considering a two stop gain (stability), then shooting f/5.6 becomes more handy at slower speeds, as if shooting f/2.8 with the same ISO.

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10-04-2008, 06:42 PM   #28
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QuoteOriginally posted by Douglas_of_Sweden Quote
Yes, but even a poor amateur had "fast" primes, the common start set was a 28mm/2.8, a 50mm/1.8 and a 135mm/2.8. Today, instead of these primes they sell consumer zoom lenses with max apertures like 4.5 to 5.6. Try buying a short and a long constant aperture 2.8 zoom lenses! It costs! All those slow zoom lenses, that's why they need to give useful 1600ISO performance.
I recall picking up a 3pk of 36exp. Kodak Gold 1000 about 20 yrs ago and thinking to myself "I can shoot anything with this!"
10-04-2008, 08:24 PM   #29
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QuoteOriginally posted by rburgoss Quote
... Test goal: To have the same subject captured by two different sensors (K20D and Optio Wpi), with the same magnificacion, using the same focal length. For this I Used the WPI at 18.9 mm setting -its longest f/l- and the K20D with my DA12-24, set at 18 mm. The crop factor between each other is what gives the angle of view)....
Thanks for the test information!

Is there any way you could post or link to the original Jpegs? I'm finding this all very hard to swallow. Especially, I'm finding the noise on the K20D sample to be absolutely horrendous for ISO 200, even with the underexposure. Are you sure you didn't switch them by accident?
10-04-2008, 09:00 PM   #30
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QuoteOriginally posted by Frank Fletcher Quote
Thanks for the test information!

Is there any way you could post or link to the original Jpegs? I'm finding this all very hard to swallow. Especially, I'm finding the noise on the K20D sample to be absolutely horrendous for ISO 200, even with the underexposure. Are you sure you didn't switch them by accident?
OP took 2 crops (piece of chain) with different number of pixels in each and then scaled at least one of them so that both will be the same size on the screen in his posting... either the crop from K20D is scaled up or the crop from WPi is scaled down...
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