[thibs]

There is nô high iso advantage to FF. There's an Iso advantage to lower pixel density (at a given sensor tech).

[Gimbal]

Wrong, a larger sensor have a high-iso advantage over a smaller sensor.

[Rondec]

There is a high iso benefit to larger sensors, but it comes only at a loss of depth of field. So for instance, if you shoot with a 55 mm f1.4 lens on APS-C, you will have the same performance as an 85 f2 lens on full frame. There was a long discussion earlier here.

[thibs]

Wrong, a larger sensor have a high-iso advantage over a smaller sensor.

No, if pixel density is the same, you'll only get more resolution.

[Gimbal]

No, if pixel density is the same, you'll only get more resolution.

I agree, if you look at only one pixel.
But if you compare the entire picture then you have gained.

[thibs]

Sure but still, thé existence of both D3 and D3x is for exactly that reason.
FF. Brings 'something' there's nonquestion over that (from me at least) but the whole picture (pun intended) should be weighted carrefuly and individualy following shooting style of each photographer. IMO the 24mpix from D3x (with its current sensor) wouldn't be enough to me to switch (considering lenses etc).
However, a middle solution, bringing better Iso (per pixel) and better resolution at a good price would tempt me a lot.

[WMBP]

FF. Brings 'something' there's nonquestion over that (from me at least)

There's no question that 36x24 has some advantages over APS. We can disagree about how significant the advantages are, but there is no disagreement that the advantages are there. Some who apparently have not read what I've said here seem to think I am saying 36x24 has no advantages. Not what I said at all.

But just as, in certain respects, APS > point & shoot, and 36x24 > APS, so medium format > 36x24. Yet the clamor is for 36x24 rather than medium format. Why? I think the answer is obvious: Price. Medium format is VERY expensive. Most of us can't imagine paying that much money for a camera. So we don't even dream about it.

36x24, on the other hand, seems almost affordable, almost within reach. So people here keep talking about the price point at which they'll buy: They'll buy if Pentax releases a 36x24 for less than $2000, or for less than $1500, or whatever. If Pentax releases a 36x24 camera for less than $1500—and assuming the reviews indicate that it's a good camera (which I expect would be the case)—heck, I'll give very serious thought to buying one myself.

Time will tell, but personally, I think this is VERY HIGHLY UNLIKELY. The Sony Alpha A900 right now (5-28-2010) seems to be the cheapest 36x24 camera, and it is just under $2000 for the body only, on Amazon.com. Nikon D700 is selling for about $2300 today, body only; and the Canon 5D MkII can be picked up for about $2500. My guess is that, in the USA, $2000 is the pricing floor for these cameras—that we should not expect to see new cameras selling for much less than that, at least not for a couple of years. And even if the price of 36x24 does come down, oh, in 2012 or so, the price of APS is likely to have come down a fair bit, too. Imagine being able in 2012 to buy an APS camera that is much better than the K-7 for a brand-new price of, oh, $800. I'll bite and spend the difference on lenses.

The video supposedly showing the benefits of 36x24 (referred to above more than once) estimates the full-frame systems to cost about THREE TIMES more than comparable APS systems.

The point is, any comparison of APS with 36x24 that ignores price, is just fantasizing. (Or, if the comparison is being made by somebody who has already spent the money on a 36x24 camera, then it's self-justification.) The bigger formats provide superior results in some situations. But you really pay a lot for those small improvements. To some photographers, it's worth it. But I think a lot of people buy stuff because they THINK it's superior, when perhaps what they should have done is learn how to take better pictures with the camera they already have. My guess is that about 70% of the people using DSLRs would be better served by a high-end fixed-lens camera. I don't mind them buying DSLRs, though, because it helps keep the costs down for me.

but the whole picture (pun intended) should be weighted carrefuly and individualy following shooting style of each photographer. IMO the 24mpix from D3x (with its current sensor) wouldn't be enough to me to switch (considering lenses etc). However, a middle solution, bringing better ISO (per pixel) and better resolution at a good price would tempt me a lot.

Ditto.

Will

[lurchlarson]

Please correct me if I am wrong.

One thing that APS-C has over FF is that there is less data to process, therefore faster image processing at lower cost. Look at the Canon 1D MarkIV. Canon dropped to APS-H from FF and that allows the camera to be more responsive.

The 645d shoots at what 1.1fps and is ~$9000. Imagine how expensive it would be if they put a processor in there that allowed it to shoot even 3fps. Pentax has issues enough getting fast image processing throughput. Give me an APS-C that shoots 6fps+, fast AF and great high ISO and you have one very satisfied photographer.

[mattdm]

One thing that APS-C has over FF is that there is less data to process, therefore faster image processing at lower cost.

That's a matter of being lower resolution, not sensor size.

[thibs]

That's a matter of being lower resolution, not sensor size.

Indeed, but I don't see anybody, at this date, coming out with a 15Mpix FF. So, in practice what he says is true even if the sensor size has indeed nothing to do with it on a theory PoV.

[Erik]

But just as, in certain respects, APS > point & shoot, and 36x24 > APS, so medium format > 36x24. Yet the clamor is for 36x24 rather than medium format. Why? I think the answer is obvious: Price.

To me, the answer is also obvious: there are A LOT of lenses designed for 36x24 that are not used to their full potential on APS-C. A lot of expensive lenses, cheap lenses, Pentax lenses, other lenses, just lots of K-mount lenses that a lot of folks would like to use the way they were intended, digitally. It's always the lenses.

[PrimeObjectif]

To me, the answer is also obvious: there are A LOT of lenses designed for 36x24 that are not used to their full potential on APS-C. A lot of expensive lenses, cheap lenses, Pentax lenses, other lenses, just lots of K-mount lenses that a lot of folks would like to use the way they were intended, digitally. It's always the lenses.

Yeah, but a 36x24 sensor would place more demands on those lenses, while an APS-C sensor allows us to enjoy using the "sweet spot" of those lenses.

[aliquis]

There is a high iso benefit to larger sensors, but it comes only at a loss of depth of field. So for instance, if you shoot with a 55 mm f1.4 lens on APS-C, you will have the same performance as an 85 f2 lens on full frame. There was a long discussion earlier here.

Which doesn't at all have to be seen as a loss. Different behavior.

Also with a 55 mm f/1.4 lens you will have the performance of a 55 mm f/1.4 lens.

But since it effectively behave like an 85 mm lens you will stand further away from your subject which will increase the DOF.

I haven't got my head around into thinking what's the difference is of said 55 mm lens on aps-c compared to the 85 mm on full frame.

Same lens = Same performance = Different usage.
Equivalent lens = Equivalent usage = ??? performance.

[aliquis]

Wrong, a larger sensor have a high-iso advantage over a smaller sensor.

Sensitivity/iso performance of the technique used had increase by a factor of 40.000 over the years. So claiming that is a little stupid. It's likely to be better, and with same technique used it most likely is. I don't know which sensor get the latest generations of manufacturing facilities and such ..

I think Panasonic claimed a four times increase in sensitivity for their coming sensors. Huge improvement in percents but not relative the long term improvements of technique used.

For instance does Canons first full frame DSLRs offer better per pixel sensitivity/noise performance than their latest APS-C 550D/7D?

Nikon D90/D300/D300s(?) pixels are 5.5 vs 3.3 micrometers^2 or sides or whatever it was against the 550D/7D. Much bigger anyway (must be square considering 12 mpx on 1.5 crop vs 18 mpx on 1.6 crop), still imho the 550D/7D images at iso 6400 look better (don't know how much additional resolution help there but probably also on a per pixel level.)

[aliquis]

No, if pixel density is the same, you'll only get more resolution.

That's a silly argument since one of you probably assumed the same amount of pixels = bigger surface area / pixel vs the other one assuming same size pixels = more pixels / the bigger surface area.