[jogiba]

Try doing a low light video like the ones made with the FF Canon 5D MKII on any other DSLR with HD video.
Canon Digital Learning Center - Sample EOS 5D Mark II Video: Reverie

http://www.usa.canon.com/dlc/controller?act=GetArticleAct&articleID=2426

[Henrik Kristensen]

Don't forget low light noise and dynamic range, both made possible because of bigger photosites.
...

Low light noise isn't really any better at same DoF. (assuming the requirement for shutter speed remains identical between the two formats)

What good is low light low noise if the DoF is too shallow and focus is off?

At very shallow DoF, you are correct!

[MikePerham]

Also amazing how quickly forgotten all of the how-expensive-its going-to-be-due-to-the-sensor-cost arguments are quickly forgotten when the praises of the 645D are being sung. The 645D is *not* a substitute for a FF dSLR from Pentax, and is the wrong product for Pentax to produce in every way that the APS-C Faithful argue that FF is times a factor of ten. When Pentax finally gets around to making a FF dSLR (hopefully before Mr. Hogan's dire predictions become true), I'm sure all of the "arguments against" FF by Pentax shooters will be forgotten.

My friend, even your name signifies your bias ...but do not let your wish for a FF 35mm style camera blind you to the roll the 645D could play. Many people using FF would use a 645D style camera for the improved IQ if it was priced around the same as the top of the line FF cameras from Nikon and Canon. Not everyone needs 8 FPS and 600mm lenses. Many are just looking for IQ - and a larger sensor and viewfinder would be more important to some than 8 FPS etc..

Many outdoor photographers, in the days of film, used both. 35mm for wild life (600mm lenses) and 645 for landscape and closeup photography. Why not in this digital era? I see Tim Fitzharris, who used a Pentax 645 film system, now uses a MF Mamyia digital system. I am sure he would have welcomed a 645D as he had all the lenses and used the brand. I also think as a studio camera, a 645D style would suite many more than FF ...anyway, time will tell and Thom Hogan has been predicting Pentax's demise for as long as I can remember, and many of his predictions have proven wrong.

[libbyh]

I won't deny that FF produces cleaner images at high ISO and better DR, but that's not really the argument. The question is more a matter of whether the IQ is really all that discernable - especially given that a lot of DSLR users I know don't even produce a lot of prints, and if so not in very large format. FF has its place - certainly in commercial work and specialized portraiture, and if Sony is any indication, FF bodies will start becoming far more attainable from a price perspective.

But , how many would really benefit from the incrementally small improvement in IQ vs the physical overhead. Put another way, would most of us prefer to have ultimate IQ, or be able to carry a more complete complement of gear in less space and weight to ensure we get the shot?

[Pentax_XTC]

Just a few points, then I'm out of this discussion:

- Full frame produces less noise, but softer images due to the larger pixel size

- APS-C produces more noise, but the images are sharper due to smaller pixel size

- Many studio photographers are already using digital medium format such as Hasselblad, Leaf, Mamiya, and Phase One. Pentax should be next.


Personally I'm happy with the IQ and the end results of my APS-C K-7, but I would sell my first born for a digital medium format. If Pentax follows the trend they used to of a low cost professional medium format, but in digital, my first born would be safe and I'd have a 645D as well.

P.S. If you want to check my facts about the pixel sizes just Google it and you will have many test results stating such.

[MikePerham]

Just a few points, then I'm out of this discussion:

...but I would sell my first born for a digital medium format. If Pentax follows the trend they used to of a low cost professional medium format, but in digital, my first born would be safe and I'd have a 645D as well.

I would sell my first born also, age 28 still living at home and dependent, but who would buy him ...love to own a 645D however.

[georgweb]

XTC and Mike, no need to part with your first borns if their names are Sony, Nikon or Canon .-)

Rondec said:
The two prominent reasons given for full frame are better viewfinder and more narrow depth of field. I guess the better viewfinder would be nice, but I struggle a lot more with too narrow depth of field than trying to get my depth of field thinner. I guess I'm just not there from a photographic standpoint.

Not at all. Imagine having an f/1.2 lens and now you are focussing this lens through the nice and easy small format viewfinder. You have set the aperture to close to f1.7 when releasing the shutter. Don't you think your pic will have better focus when prefocussed more precisely ? Also, more often than expected, I find myself guessing focus cause the light's too dim. A brighter VF would help here obviously.

Having recently read on this forum about the importance of manual focus ability (cause in doubt even the 'pros' would switch off the errant AF), and being a manual focus guy myself, I believe the bigger VF is just huge for me and many others. If you have a chance to look through a Rollei SL35E viewfinder, well yes I would love to have that on a digital SLR. If however you have peeked through a Zenit E, that's the other end of a small format viewfinder, it's just unbelievably worse.


Probably much easier with a small format VF: Low light stuff. MF lens @f/2

For many people - me included - the wide angle lenses are already there. There is an SMC-Tak 3.5/28 waiting for that small format camera, not to forget the jawdropping Contax Distagon 28/2.8, a 150,-US-$ lens (used price obviously).

One thing that's definitely worse with small format is the bigger size - I for one would not bother a sophisticated mirrorless camera in small format and manually focussing through the main LCD display - who would anyway.

Best, Georg (the other)

[24X36NOW]

Low light noise isn't really any better at same DoF. (assuming the requirement for shutter speed remains identical between the two formats)

What good is low light low noise if the DoF is too shallow and focus is off?

At very shallow DoF, you are correct!

Yes, actually, it is, because you have failed to account for the 1 stop of light lost by APS-C (because the image circles are far bigger than the undersized sensor) that must be made up by increasing the ISO another stop as compared with FF.

[24X36NOW]

Many people using FF would use a 645D style camera for the improved IQ if it was priced around the same as the top of the line FF cameras from Nikon and Canon.

As I said, how quickly we forget. Something about yields and wafers...



Oh yes, and let me add - ALL OF US would be using FF cameras if they were priced around the same as APS-C cameras - because if they were, from the beginning, there never would have been an APS-C dSLR in the first place! COST is the sole reason for the existence of APS-C dSLRs. That is the only actual advantage.

[Marc Sabatella]

Yes, actually, it is, because you have failed to account for the 1 stop of light lost by APS-C (because the image circles are far bigger than the undersized sensor) that must be made up by increasing the ISO another stop as compared with FF.

For anyhow not following the other FF thread, be warned the above statement is not true. I have no idea where he got that notion - certainly not from any actual tests, from any book on photography, or even from any reputable web site. This doesn't even qualify as a common myth - it's a new one on me.

For the record: a given f-stop, shutter speed, and ISO produce exactly the same exposure, whether you are talking about APS-C, FF, MF, 4/3, or P&S.

At most you might see a slight variation because lenses don't necessarily state their aperture completely accurately, nor do cameras always state their ISO completely accurately. But whatever variation there is here, it will be random - it's as likely to yield a darker exposure on an FF camera as an APS-C camera.

[Rondec]

The biggest reason for medium format is avoiding diffraction limits. Ansel Adams regularly shot f22 and f35 on large and medium format. You would never dream of doing that even with Full frame -- diffraction would significantly soften your image.

That said, I don't shoot at that often in ever day situations, but for some macro shots or landscapes, it would be nice.

[24X36NOW]

For anyhow not following the other FF thread, be warned the above statement is not true. I have no idea where he got that notion - certainly not from any actual tests, from any book on photography, or even from any reputable web site. This doesn't even qualify as a common myth - it's a new one on me.

For the record: a given f-stop, shutter speed, and ISO produce exactly the same exposure, whether you are talking about APS-C, FF, MF, 4/3, or P&S.

At most you might see a slight variation because lenses don't necessarily state their aperture completely accurately, nor do cameras always state their ISO completely accurately. But whatever variation there is here, it will be random - it's as likely to yield a darker exposure on an FF camera as an APS-C camera.

I'll repeat this, as you say, "for the record."

I invite you all to:

1. Take an incident light reading with a hand held meter of the same light as that falling on your subject.

2. Set your APS-C dSLR manually to the appropriate combination of ISO, F stop and shutter speed (e.g., 1/500 @ f 11 at ISO 200 for a front lit subject on a bright sunny day).

3. Shoot.

Your photo will be underexposed.

Then, add a stop of additional exposure by any method you wish, i.e., reduce shutter speed or open up one f stop or increase to ISO 400, and shoot the same image.

Your photo will now be properly exposed.

[No PP allowed, of course ]

[Andrew Faires]

I'll repeat this, as you say, "for the record."

I invite you all to:

1. Take an incident light reading with a hand held meter of the same light as that falling on your subject.

2. Set your APS-C dSLR manually to the appropriate combination of ISO, F stop and shutter speed (e.g., 1/500 @ f 11 at ISO 200 for a front lit subject on a bright sunny day).

3. Shoot.

Your photo will be underexposed.

Then, add a stop of additional exposure by any method you wish, i.e., reduce shutter speed or open up one f stop or increase to ISO 400, and shoot the same image.

Your photo will now be properly exposed.

[No PP allowed, of course ]

Until a FF and aps-c camera are released with a confirmed match to the ISO standards that film had to adhere to, I'm chalking your findings up to variance in what your sensors say is ISO 100 (as an example).

Instead, I'll offer up a challenge to you. Pick two formats ranging from Medium format down to aps-c (I'm exluding LF as bellows extension can be a pain in the arse). The catch is it must be the exact same film (say t-max 100) and shoot using the same aperture and shutter-speed. I'm willing to bet your myth is busted as soon as the film comes back from the lab (no push or pull processing allowed).

An interesting side-note regarding your incident light meter; it doesn't qualify its exposure based on the format your using.

[kittykat46]

Lets take an FA lens , film-era, so there is no difference in the lens.
For the same scene brightness, and aperture setting, the intensity of light exiting the end of the lens is the same.
Whether you have a roll of film, a digital FF sensor or APS-C sensor at the focal point doesn't change any of that.
The intensity of light at the focal point is the same. APS-C captures a smaller area of the image, that's all.

I shot film on SLR from age 15, for nearly 20 years. Apart from individual variation in bodies and lenses, I haven't noticed any real difference in how to work exposure.

Now, one thing to be very clear about. With digital cameras, the "ISO" rating is a matter of electronics, and there IS variation in interpretation between brands , even different models of the same brand. Its one of the reasons Hand-Held exposure meters don't work that well with digital. The camera's own exposure system is more well tuned to the built-in behaviour.

Film was a lot more standardised than that - some difference in ISO performance between Kodak film and Fuji , for example, but not by much.

[lol101]

I'll repeat this, as you say, "for the record."

I invite you all to:

1. Take an incident light reading with a hand held meter of the same light as that falling on your subject.

2. Set your APS-C dSLR manually to the appropriate combination of ISO, F stop and shutter speed (e.g., 1/500 @ f 11 at ISO 200 for a front lit subject on a bright sunny day).

3. Shoot.

Your photo will be underexposed.

Then, add a stop of additional exposure by any method you wish, i.e., reduce shutter speed or open up one f stop or increase to ISO 400, and shoot the same image.

Your photo will now be properly exposed.

[No PP allowed, of course ]

Just did that with my 5D and 1000D... both gave me the same (correct) exposure when I manually dialed the settings read from my light-meter.

Now what?

In addition, I must add that they gave me the same exposures but not the same pictures due to non-matching DoF.

When I dialed an extra f-stop on the APS-C lens (to match DoF), and thus lowered the ISO one stop to keep the exposure constant, the two cameras gave me virtually indistinguishable pictures.

Morality: as long as you can dial this extra stop on your lens, you'll get the same result on APS-C as with a FF.

Morality 2: when you can't dial the needed extra stop on your APS-C setup... you remember why you got a FF.