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01-18-2008, 03:44 AM   #16
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QuoteOriginally posted by Ishpuini Quote
That's wrong. It's not because APS-H doesn't vignet that 28.7mm x 28.7mm won't vignet. After all, the corners of the APS-H rectangle may still fall just within the circle of confusion of the DA lenses (which for this must have a minimum diameter of 34.5mm), the square you describe is higher and will most likely exceed the circle of confusion (minimum diameter of 40.6mm!). The maximum square within the minimum APS-H circle of confusion is approx 24.4mm x 24.4mm, that's a surface of 594mm squared.

Plus... SR needs some margin to move around and thus requires an circle of confusion which is larger by a margin than the sensor diameter, not "just" larger. So, if you want to retain SR, APS-C is probablt still the only way, regardless of vignetting on a APS-H sensor or not...

Wim
You seem very confused about what a circle of confusion is.
You are meaning the coverage of the lens (it's image circle size), but using a term which relates to whether someting is considered in focus or out of focus.

01-18-2008, 03:51 AM   #17
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QuoteOriginally posted by pw-pix Quote
You seem very confused about what a circle of confusion is.
You are meaning the coverage of the lens (it's image circle size), but using a term which relates to whether someting is considered in focus or out of focus.
Ok, I indeed mixed up the terms, but the reasoning goes for the image circle just as well... No way such a big 1:1 sensor would fit...

Thanks for setting me straight!

Wim
01-18-2008, 07:12 AM   #18
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QuoteOriginally posted by ruemiser Quote
I'm curious, but it would be interesting if Pentax decided to use a full 35mm size CCD as with the higher priced Canon's and Nikon's. That would really give this model another edge. Does anyone have any info as to what type and CCD will be used?

- Dave
CCD is more expensive than CMOS, especially in small quantities. So, if the Pentax uses a full size (24x36mm) CCD, it will be more expensive than the sensors in Canon and Nikon cameras. It will not give Pentax an edge. As of now, only Dalsa and Kodak have full frame 35mm CCD sensors, and neither one is known for cheap prices. In fact, even Kodak used a full frame CMOS sensor from Fill Factory (now Cypress) in its own 14N full frame DSLR to keep costs low.
01-18-2008, 07:22 AM   #19
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QuoteOriginally posted by nosnoop Quote
Forget about Full Frame (35mm) size sensor from Pentax. There won't be any in the foreseeable future. And I don't see the point either. The price of such camera will be in the stratosphere, affordable by few, and will remain as a niche product. Maybe in the distant future if the price would come down (which I doubt). APS-C sensor camera would always hold a significant price advantage.

K20D will use 14.6MP CMOS sensor. And if the low light capability is as good as rumors suggest (possible ISO 6400 available), then why do we need pay thousands more for a Full Frame camera except some professionals with specific needs?
I disagree. Full frame is rapidly becoming mainstream. The Canon 5D is selling for around $2100, hardly stratospheric in price. In fact, it is only about $300 more than APS-C cameras like the Nikon D300, Fuji S5 and the Olympus E-3, which has an even smaller 4/3 sensor. I don't think $300 is a "significant" price advantage.

The Nikon D3 is not cheap. It costs $5,000. Yet there is news that production of the D3 will be increased to 10,000 units per month. That is hardly a camera for the "few."

If the K20D uses a 14mp APS-C sensor, the laws of physics would dictate that its high ISO noise level is going to be worse than the 10mp K10D. Only by increasing sensor size to full frame can a 14mp camera be expected to have low noise at the current stage of evolution of sensor technology. People do not need to pay thousands more for a full frame DSLR. They only need to pay a few hundred dollars more. Full frame DSLR cameras, if and when they fall below $2,000, will become mainstream and begin to replace APS-C cameras in the market place.

01-18-2008, 07:41 AM   #20
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QuoteOriginally posted by Anastigmat Quote
If the K20D uses a 14mp APS-C sensor, the laws of physics would dictate that its high ISO noise level is going to be worse than the 10mp K10D. Only by increasing sensor size to full frame can a 14mp camera be expected to have low noise at the current stage of evolution of sensor technology. People do not need to pay thousands more for a full frame DSLR. They only need to pay a few hundred dollars more. Full frame DSLR cameras, if and when they fall below $2,000, will become mainstream and begin to replace APS-C cameras in the market place.
We'll see about the law of physics vs. technology in a few weeks...

However, why should the FF, even falling in price, ever replace APS-C?

I know that FF IQ is better at a given number of pixels and that there are some things that a FF can do that an APS-C cannot but I think that, as of today, it would be very difficult to tell an image taken by a 5D from an equivalent image taken with, say a 40D when printed up to 40x60cm.

You have to go more and more to the details, or specialized needs, nowadays to truely give FF an advantage.

I don't see the need for the general public (I count myself in that category of course), to pay, even a few hundreds more as you put it to get some improvements that are likely not to be discernable in prints smaller than 40x60cm.
01-18-2008, 08:30 AM   #21
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QuoteOriginally posted by Anastigmat Quote
People do not need to pay thousands more for a full frame DSLR. They only need to pay a few hundred dollars more. Full frame DSLR cameras, if and when they fall below $2,000, will become mainstream and begin to replace APS-C cameras in the market place.
Replace-no, supplement-yes. A good 18mm DA lens will cost close to $1,000. If there was a 28mp FF Pentax for less than $2,000 I'd buy it for wide angle shooting rather than a 18mm DA lens. Sensor technology has advanced far enough that noise can be controlled at 12-14 mp on a APS-C and 28-32 mp on a FF sensor.

The DSLR market has gotten big enough so the manufacturers will have to start looking for niche markets. Oly is already doing it with the 4/3ed sensor. IMO we will start to see bodies designed for specific markets, I.E. pocketable and landscape to name just two. The trend will be, you have multiple lenses, why not multiple bodies. A $1,500-$2,000 FF body will of course kill the chances of ever seeing a MF body from Pentax.
01-18-2008, 08:35 AM   #22
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QuoteOriginally posted by Anastigmat Quote
If the K20D uses a 14mp APS-C sensor, the laws of physics would dictate that its high ISO noise level is going to be worse than the 10mp K10D. Only by increasing sensor size to full frame can a 14mp camera be expected to have low noise at the current stage of evolution of sensor technology. People do not need to pay thousands more for a full frame DSLR.
Very nice BS, can even smell it here.
01-18-2008, 08:37 AM   #23
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Square Sensor

A square sensor would mean a square lcd on the back, which would either mean smaller horzontal dimension than we are getting used to seeing, or larger vertical dimension that would change the shape of the camera. No necessarily a negative, but it is a consideration.
Mike

01-18-2008, 08:45 AM   #24
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[QUOTE=ZaphodB;155225]I continue to be amazed by this idea going around that a camera or lens using a sensor size a little bit larger (the size of film negs/slides many of us used without complaint for many years) must inherently be too large and heavy for a human being to carry. Or that APS-C ones are wonderful featherweight things you can carry in your pocket.

Well, the camera bodies are not much different, however, lenses are. Overall, my MZ-S and a 70-200 f/2.8 is bigger and heavier than my K10D with the DA* 50-135 - particularly in the Lens department.

Mike.
01-18-2008, 08:47 AM   #25
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QuoteOriginally posted by regken Quote
Replace-no, supplement-yes. A good 18mm DA lens will cost close to $1,000. .
I have a very good DA 18mmf4 at home, it has almost no vigneting, no distorsion, very small AC and excellent sharpness... would you care to buy it from me for $1000?

But wait, for the same price, I will include FOR FREE, a DA 12f4, a DA 14f4, a DA 16f4, a DA 20f4 and a DA 24f4 of about the same quality!

I am waiting for your offer (since I paid 600 for the all pack, I can't loose)...
01-18-2008, 08:49 AM   #26
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[QUOTE=MikePerham;155603]
QuoteOriginally posted by ZaphodB Quote
I continue to be amazed by this idea going around that a camera or lens using a sensor size a little bit larger (the size of film negs/slides many of us used without complaint for many years) must inherently be too large and heavy for a human being to carry. Or that APS-C ones are wonderful featherweight things you can carry in your pocket.

Well, the camaera bodies are not much different, however, lenses are. Overall, my MZ-S and a 70-200 f/2.8 is bigger and heavier than my K10D with the DA* 50-135 - particularly in the Lens department.

Mike.
Be prepared for the answer that the equivalent lens of the DA 50-135f2.8 would be an FA 70-200f4 of similar price and bulk... :ugh:
01-18-2008, 08:58 AM   #27
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[QUOTE=lol101;155607]
QuoteOriginally posted by MikePerham Quote

Be prepared for the answer that the equivalent lens of the DA 50-135f2.8 would be an FA 70-200f4 of similar price and bulk... :ugh:
Only in respect to equivalent DOF; otherwise f2.8 is f2.8 regardless of sensor size.
01-18-2008, 09:06 AM   #28
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[QUOTE=lol101;155607]
QuoteOriginally posted by MikePerham Quote

Be prepared for the answer that the equivalent lens of the DA 50-135f2.8 would be an FA 70-200f4 of similar price and bulk... :ugh:
The DA* is a full stop faster and even smaller (shorter) than the A 70-200 F/4 manual focus lens I used back in my LX days. Anyway, I think an apple to apple comparison should compare FOV and lens speed. The longer the lens the more the advantage of the DA* series becomes apparent. When available, a DA* 400 f/4 will be a lot smaller than the FA* 600 f/4 at 149mm in length and weighing 6800g.

Mike
01-18-2008, 09:13 AM   #29
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[QUOTE=jamesk8752;155619]
QuoteOriginally posted by lol101 Quote

Only in respect to equivalent DOF; otherwise f2.8 is f2.8 regardless of sensor size.
Yes, that's what I said: equivalent lenses = same DoF, FoV and shutter speed from same distance, ISO_FF = ISO_APS+1 stop though... so you'd better have more than a one stop advantage in ISO noise on FF compared to APS-C to get the so called "FF better IQ".

In other words, you'd be able to take the same pics on a FF with a 70-200f4 that the one you are able to take on an APS-C with the 50-135f2.8.

Anyway, all this equivalence talk is not really my cup of tea.

I understand it but since I have no problem getting the pics I want from an APS-C cam... I don't really get the argument that the only chance of survival for Pentax is to go FF right away...
01-18-2008, 09:34 AM   #30
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QuoteOriginally posted by lol101 Quote
I have a very good DA 18mmf4 at home, it has almost no vigneting, no distorsion, very small AC and excellent sharpness... would you care to buy it from me for $1000?

But wait, for the same price, I will include FOR FREE, a DA 12f4, a DA 14f4, a DA 16f4, a DA 20f4 and a DA 24f4 of about the same quality!

I am waiting for your offer (since I paid €600 for the all pack, I can't loose)...
First of all I don't want a zoom! Even if I did the DA 12-24 sells for $720, not $600. I'd buy a FF 28mp body for $2000 before I'd buy the DA 12-24 for $720.
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