So, how big is a WHOLE enchilada?

You've often seen me grouse about the use of the phrase "full frame" as a shorthand for "full-frame 35-mm" when referring to the 36 mm x 24 mm format size. My complaint about the use of the term has two prongs:

- There are of course formats other than the full-frame 35-mm format that are quite properly spoken of as "full frame", such as "full frame 8" x 10"". (In fact, just "35-mm" without the "full-frame" would be a better shorthand, since it is quite reasonable to take "35-mm" without any qualification, such as "half frame", to mean the 36 mm x 24 mm version, assuming we are contemplating still camera photography.)

- The use of the term often implies that the 36 mm x 24 mm format is somehow the ne plus ultra, the res maximus, the "whole enchilada" of photographic formats. (It is of course if one limits oneself to, for example, current Canon or Nikon digital bodies!)

It is interesting to see Hasselblad, in recent times, refer to a "full frame 48 mm x 36 mm format", describing some of their slightly smaller formats as being "slightly smaller than true 48 mm full frame".

It's nice to see them be careful about the notation.

It will be interesting to see what happens when Hasselblad introduces their new "645" format digital system.

Doug,

I think it's more helpful to think of function. To me having a slightly smaller sensor in the D40, D30, D20, D10 and Rebel series of 1/1.6 one can effectively sample a small part of the image circle where one has interest, say the head of a bird, by using a 70-200mm lens one owns and getting the reach of a 320mm lens for that same imaged area without moving ones position relative to the subject being photographed. After all, if I cannot jump over the fence and don't own a longer lens, using an inexpensive D40 can give me ~ the same result in information as a "full size sensor, the 1Ds III, for example, in which I'd only be using a small patch in 1/1.6 of the surface area.

So Normal and full size should be replaced with just the designation of multiplication factor, format (35mm, 48mm and so forth) as well as sensel pitch.

Hardly ever is the pixel cont now the limiting factor. Designation should be something like

12MP type35/1.6 SP 64

Which would mean a 12MP 35mm format sensor that is 1/1.6 the full frame 35mm design and has sensel pitch of 64 microns. With this we'd know more about the capability of that camera than using terms like "full frame" or not.

Hi, Asher,

Asher Kelman said:

So Normal and full size should be replaced with just the designation of multiplication factor, format (35mm, 48mm and so forth) as well as sensel pitch.

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Well, I understand.

But what should be taken as the "base" for the size ratio, and why? Should we always use the 36 mm x 24 mm frame size, for consistency (albeit arbitrary)? Then the "factor" for a 48 mm x 36 mm format would be 0.72.

Or should we use the frame size that is "most common" in the "genre" of cameras being discussed? If the latter, then for a Hasselblad-style body of some sort, should the reference be 48 mm x 24 mm, or perhaps (as Will Thompson suggested to me last night) 56 mm x 56 mm (he actually said, "6 by 6") based on the notion that this was the "first widely used format" of the medium format genre? (Is that true?)

But maybe for all Canon bodies with three- and four-digit model numbers, the reference should be 22.5 mm x 15 mm, since that is (approximately) the uniform sensor size within that genre.

Or perhaps it is interchangeable lens product line families that confer the size reference (which is really the premise of the "full-frame 35-mm" reference scheme). The reference would be the largest format size of the cameras intended to use a substantial part of the lens family. Of course we can't then use the notation at all for cameras not having interchangeable lenses.

Perhaps, since the Four-Thirds system is intended to provide a "norm" for interchangeable lens SLR digital cameras, we should use its format size (17.3 mm x 13.0 mm) as our reference.

Actually, my suggestion is that we should describe sensor sizes by giving their size (!), along with of course the sensel pitch if that is of interest (which of course it often is). Then, if we want to compare it qualitatively with the format size of some other camera ("This is only slightly smaller than the format size of the more expensive Ajax 1000") we just do that.

Doug,

I think you should take it where it's coming from... The simple fact of the matter is, in the world of the compact cameras, nobody knows or cares what the size of their sensor is. I.e. 99% don't know, the other 1% don't care. Point, shoot, and (hopefully) be happy.

The overwhelming majority of SLR users (digital or otherwise) uses the 35mm system, and most of them do care about the size of the sensor, as it is so intrinsically coupled to lens angle-of-view (a component of their system they have control over, since they can change them), sensor noise, depth-of-field, etc. So, this segment of the market (which is 99% of the SLR market) can rightfully speak of "full frame", because most of the current equipment have smaller-than-film sensors for reasons of cost and technology limitations (up to recently, in anyway).

But you know this. I don't think you should take any offense to this statement, or let it bother you. For 35mm photography, yes, the term "full frame" is the whole thing, the whole enchilada.

I do not believe (Asher, as you have partially alluded to) that any single term can or should be used as a base, with the other sensor sizes being referred to with some factor. For me, "full-frame" (and "only-frame", as digital backs are so expensive) is 6x7cm on my SLR. And today's current (largest) ~5x4cm digital backs will be pitifully small (i.e. introduce a huge 'crop factor') in that space, in a camera which already has a limited lens lineup.

For my colleague, four-thirds is "full-frame" on his SLR, because the entire system is designed around an image circle for a fixed, full-size.

For large format, there is no real standard whatsoever, as each different lens can cover a different image projection area.

I think sensor size should simply be stated in terms of the dimensions (like it has been done for years on medium and large format cameras, i.e. Mamiya RB67, Linhof Technorama 617, etc) and everybody should just "get over it" and choose a camera based on the qualities they desire.

Making a "upfront" marketing thing out of sensor sizes has been blown out of proportion, in my opinion. It should be treated similarly to cars, where every spec of the engine is not thrown in your face, but where the information is easily accessible in standard terms and units. And, like in cars, people should stop drawing too many conclusions from the specs, and try the thing out before they buy. The specifications usually only tell half the story...

Hi, Dawid,

Well said.

Best regards,

Doug

The Phase One enchilada

I see that Phase One has announced their P65+ back, which is said to be "full frame 645" in size.

Well, if we consider the "645" film format to be 56 mm x 41.5 mm (a common implementation), then the new Phase One back, at a format size of 54.9 mm X 40.4 mm, probably deserves that moniker.

The obsessed can describe it as a "factor 1.02" sensor (in the "645" world, of course).

Doug_Kerr said:

I see that Phase One has announced their P65+ back, which is said to be "full frame 645" in size.

Well, if we consider the "645" film format to be 56 mm x 41.5 mm (a common implementation), then the new Phase One back, at a format size of 54.9 mm X 40.4 mm, probably deserves that moniker.

Click to expand...

Close enough! The enchilada just got bigger (as did the price on the tag).
It will be interesting to see what Dynamic range they can pull out of that Dalsa chip, and how well they cope with the stitching needed in the stepper process to achieve the size.

Bart

The term 35mm for a DSLR by definition is full frame, a crop sensor isn't 35mm. Given that medium format digital backs don't even make up a fraction of the sales of digital cameras I will quite happily ignore them when using a term to define sensor size, to be honest, who cares about MF apart from a tiny fraction of MF shooters, it's so specialised a sector that it can not be used to define a term or indeed complain that a term doesn't apply to them. Given that when referring to a DSLR 99.999% of people mean a 35mm DSLR, the phrase 'full frame' is perfectly appropriate to defrentiate between crop sensors which ruled for about 4 years but will probably now only be used in the cheapest entry level cameras in the near future. 'FF' or 35mm a a size of medium for a DSLR form camera has been around for some 100 or so years and apart from a slight and breif aberation in the form of crop sensors, will continue to do so for the near future if only to support the current lens line of all the manufacturers. The term FF was first invented to diffrentiate between that and crop cameras with the very definate impression that anything else was not full, i.e. less than ideal or perfect. I'm in perfect collusion with that.

BTW this is not a diss at medium format shooters, I just think that it's appropriate for the vast majority to be able to define a term without referrring to a tiny minority. Same as 35mm has long ago stopped being referrred to as the 'tiny' format given the vantage point of the vast majority of people doing the referring.

Hi, Ben,

Ben Rubinstein said:

Given that when referring to a DSLR 99.999% of people mean a 35mm DSLR . . .

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Well, I doubt that.

I doubt if most people who speak of a DSLR today are specifically thinking of a 35-mm format size DSLR.

Maybe what you mean to say is that people who speak of a DSLR mostly mean one from a design family derived from a 35-mm film camera , or from a digital camera design family whose largest member (existing or anticipated) would have a full-frame 35-mm format size.

But, given the existence and increasing acceptance of Four-Thirds system DSLRs, I wonder if your fraction of 99.999% is a bit overstated.

'FF' or 35mm a a size of medium for a DSLR form camera has been around for some 100 or so years . . .

Click to expand...

More like 72 years - how time flies when you're having fun! (I assume you mean "SLR form" camera - if you really mean DSLR the time span is considerably shorter than that!)

And of course the first widely used SLR (dating back almost 95 years) was typically found in such formats as 2-1/4"x3-1/4", 3-1/4"x4-/14", 4"x5", and 5"x7" .

Best regards,

Doug