[beachy]

i've read about full frame cameras such as the canon 5D, can someone please explain what exactly these are, and what are the advantages on these type of DSLR,s as opposed to others,and if you went for a full frame model would you have to replace all your len,s ? also are any of the nikon range of DSLR,s full frame, excuse my ignorance on this, thanks in advance

[Jazz Monkey Jr]

The full frame cameras have full frame sensors, the same size as 35mm. So if you go from a SLR to a full frame digital SLR, then the pictures will be the same and the lenses will fit.
When you buy a lower end DSLR like the canon 400D, Nikon D50 then the sensor is smaller, called a crop sensor and is usually 1.5x or 1.6x smaller, this means that yur full frame lenses will work but the sensor doesn't see all what the lens sees, that is why you have to multiply your lenses, so a 100mm lens become 160mm equivalent on a caqnon 400D. It is a bit like cropping the photograph.
There are lenses on canon called EF-S, the S means shorter focal length and these lenses are designed for the smalled sensor, so they can be closer to the sensor and the sensor sees the full mage.

So basically, normal lenses will work on a crop sensor but the shorter lenses won't work properly on the full frame cameras (you will see the sides of the lens on the picture, called vignetting)

[salubrious_k]

I'm not absolutely sure, but I thought the 5D was a 1.3X crop factor?

One aspect (other than the focal length) is that a full frame camera has more pronounced bokeh at lower apertures (ie the background to a portrait shot will be more blurred).

[h4rri]

Originally Posted by salubrious_k

I'm not absolutely sure, but I thought the 5D was a 1.3X crop factor?

One aspect (other than the focal length) is that a full frame camera has more pronounced bokeh at lower apertures (ie the background to a portrait shot will be more blurred).

Nope it's full frame

The other thing this is that the EF-S lenses won't work as the lense has the potential to damage the mirrors because of the deeper back

It also has a larger and brighter viewfinder

[beachy]

Originally Posted by Jazz Monkey Jr

The full frame cameras have full frame sensors, the same size as 35mm. So if you go from a SLR to a full frame digital SLR, then the pictures will be the same and the lenses will fit.
When you buy a lower end DSLR like the canon 400D, Nikon D50 then the sensor is smaller, called a crop sensor and is usually 1.5x or 1.6x smaller, this means that yur full frame lenses will work but the sensor doesn't see all what the lens sees, that is why you have to multiply your lenses, so a 100mm lens become 160mm equivalent on a caqnon 400D. It is a bit like cropping the photograph.
There are lenses on canon called EF-S, the S means shorter focal length and these lenses are designed for the smalled sensor, so they can be closer to the sensor and the sensor sees the full mage.

So basically, normal lenses will work on a crop sensor but the shorter lenses won't work properly on the full frame cameras (you will see the sides of the lens on the picture, called vignetting)

so am i then right in thinking you won't necessarily get better picture quality from a camera that is full frame, as some of the more expensive DSLR's ie nikon D200 are not full frame, and if i put a 35mm SLR lens on a cropped sensor digital camera it will then only work in manual and not AF mode ?

[lmccauley]

Originally Posted by beachy

so am i then right in thinking you won't necessarily get better picture quality from a camera that is full frame, as some of the more expensive DSLR's ie nikon D200 are not full frame,

True. Another example of a cropped sensor camera is the Nikon D2Xs.

and if i put a 35mm SLR lens on a cropped sensor digital camera it will then only work in manual and not AF mode ?

It depends on exactly which lens.

e.g. the Nikkor AF 50mm f/1.8 D will autofocus on both 35mm film and cropped DX format digital Nikon cameras.

Cheers,
Liam

[T0MAT01]

Originally Posted by beachy

so am i then right in thinking you won't necessarily get better picture quality from a camera that is full frame

It depends how big you are going to print your photos.
Since the sensor is bigger to start with, the image isn't expanded/stretched as much as the same photo would be taken on a 1.5x or 1.6x crop camera.

Originally Posted by beachy

if i put a 35mm SLR lens on a cropped sensor digital camera it will then only work in manual and not AF mode ?

The lens will still autofocus, as long as it is an autofocus lens!

[lmccauley]

Originally Posted by T0MAT01

It depends how big you are going to print your photos.
Since the sensor is bigger to start with, the image isn't expanded/stretched as much as the same photo would be taken on a 1.5x or 1.6x crop camera.

I don't think too many owners of the Nikon D2Xs are worried not being able to print big

Cheers,
Liam

[Radiohead]

Originally Posted by salubrious_k

One aspect (other than the focal length) is that a full frame camera has more pronounced bokeh at lower apertures (ie the background to a portrait shot will be more blurred).

Bokeh is, strictly speaking, more dependent on lens/aperture design than the sensor size. I think what you mean here is that, for a given focal length, a FF sensor will have a shallower depth of field than an APS-C or APS-H sensor.

Bokeh is also not exclusive to portrait shots.

One oft-quoted advantage of FF is that they typically offer lower noise characteristics than APS-C sensors due to having larger photosites that are less densely packed. The 5D and D2x have almost identical resolution, but the 5D comfortably outperforms the D2x at higher ISO's (ie. 400 and above).

The downsides of FF can be less tolerance of average optics, softer corners and some vignetting if not stopped down due to using more than just the sweet spot of the lens.

[salubrious_k]

Originally Posted by Radiohead

Bokeh is, strictly speaking, more dependent on lens/aperture design than the sensor size. I think what you mean here is that, for a given focal length, a FF sensor will have a shallower depth of field than an APS-C or APS-H sensor.

That's exactly what I meant, although admittedly I think I confused the issue by trying to say it in layman's terms.

Although I would argue that "more pronounced bokeh" means the same as "shallower depth of field". After all I thought bokeh comes from the japanese "bo-ke" meaning "blur" or "fuzziness". Or maybe I've had the wrong idea for a while? If referring to "smoother" bokeh, then I'd definitely agree that the more aperture blades the better (within the realms of possibility of course).

[dood]

a very simplistic consideration: the FF sensors' advantages are more geared to wide angle photography. If you use the tele end more, then the crop sensors are probably better suited.

[Radiohead]

Originally Posted by salubrious_k

That's exactly what I meant, although admittedly I think I confused the issue by trying to say it in layman's terms.

Although I would argue that "more pronounced bokeh" means the same as "shallower depth of field". After all I thought bokeh comes from the japanese "bo-ke" meaning "blur" or "fuzziness". Or maybe I've had the wrong idea for a while? If referring to "smoother" bokeh, then I'd definitely agree that the more aperture blades the better (within the realms of possibility of course).

No - I'd agree with regards to more pronounced bokeh.

EDIT: Actually I;m not sure I would. Depth of field and bokeh are related but still distinct. Depth of Field (to me at least) means what it suggests, whereas I've always taken bokeh to mean the way a lens renders the OOF areas of an image, and the transition from in to out of focus.

So, to use the Canon 85mm's as an example, both the f1.2 and f1.8 will have the same DOF at, say f2, but the f1.2 will have a smoother bokeh than the f1.8 model.

[salubrious_k]

I see your point, I guess we just have different semantic views of the word. I'd say that at f/2 the f1.2 and the f1.8 would have the same amount of bokeh, but that the f1.2's bokeh would be smoother.

I'm pretty sure I use the word in the wrong context though as I've never really had the concept explained to me definitively, so I'll defer to your judgement :D

[Mr_Sukebe]

Within the Canon range, their are 3 types of sensor size for their D-SLRs:
- Full Frame: 1DS, 1DS mk2 and 5f
- 1.3x crop: 1D, 1D2, 1D2n
- 1.6x crop, 10D, 20D, 30D, 300D, 350D, 400D etc

As I understand it the key benefits to full frame are:
1. The functional benefit of not needing to buy seriously wide angle lenses. Having said that, this has mostly been mitigated against with the introduction of super wides from Canon and others. In addition, there's clearly a trade off in then requiring a seriously enourmous telephoto for long range shots such as bird shooting.
2. Lower pixel density. This is generally recognised as a good thing. The bigger the sensor, the more data a camera has to work with to begin. It's a bit like comparing an LP running at 45rpm to 33rpm. In theory, you should get a better photo from a larger sensor, all other technology being equal.

I don't really follow this very closely, but this is my understanding:

With the coming of digital, the photo industry knew that the old full frame would not be ideal long term. The large sensor would cost more, and not deliver a better image long term. However, during the rapid development phase (which we are still, just, in) the best full frame sensor performs as well as a smaller sensor, but a year or so earlier. Also, old 35mm lenses are of course optimised for a full frame sensor. So, up to now, the latest full frame sensors have had the edge in absolute performance (and cost). But if you're considering an older full frame digital, it may be better to choose a newer small sensor camera of equivalent performance.

Nikon explicitly transitioned to their expected final sensor size from the outset (D1). This did give Nikon some disadvantage compared to Canon who have used different sensor sizes opportunistically to deliver leading edge performance. However, in five or ten years time, an old Nikon with standard sized sensor is going to fit in with current lenses and equipment better than an old full frame Canon.

In summary, the theoretical maximum resolution of full frame is not, in fact, better than the smaller sensor (something to do with diffraction I think); so the smaller sensor is a forward-looking choice, and the full frame a backward looking choice. Each has their specific advantages.

About bokeh and depth of focus / depth of field

My understanding is that "bokeh" is normally used to refer to the quality of the out of focus blur, not to its amount. For example a mirror telephoto lens typically shows very strong blurring of the background, but horrible bokeh because bright spots are rendered into distracting little rings.

The easiest way to understand the relationship of depth of focus to sensor/film size is that it is essentially the same for all sizes at the same aperture provided everything is scaled along with the sensor size. Thus, if you have a sensor fifty percent bigger, the blurring will be the same at the same aperture, provided the lens focal length is 50% bigger, the subject and background are 50% bigger and 50% further away. (people with 50% bigger heads are, however, a rarity - so this isn't actually useful)

So large format gives shallower depth of field because the whole camera is larger in relation to the subject and subject distance. To offset a small sensor, you need a wider aperture to get shallow depth of field. Conversely, you'll see shallow depth of field come back with a vengeance when you do close-up photography when even a small camera becomes big compared to the subject.

[Radiohead]

Originally Posted by ancientgeek

With the coming of digital, the photo industry knew that the old full frame would not be ideal long term. The large sensor would cost more, and not deliver a better image long term. However, during the rapid development phase (which we are still, just, in) the best full frame sensor performs as well as a smaller sensor, but a year or so earlier. Also, old 35mm lenses are of course optimised for a full frame sensor. So, up to now, the latest full frame sensors have had the edge in absolute performance (and cost). But if you're considering an older full frame digital, it may be better to choose a newer small sensor camera of equivalent performance.

Nikon explicitly transitioned to their expected final sensor size from the outset (D1). This did give Nikon some disadvantage compared to Canon who have used different sensor sizes opportunistically to deliver leading edge performance. However, in five or ten years time, an old Nikon with standard sized sensor is going to fit in with current lenses and equipment better than an old full frame Canon.

In summary, the theoretical maximum resolution of full frame is not, in fact, better than the smaller sensor (something to do with diffraction I think); so the smaller sensor is a forward-looking choice, and the full frame a backward looking choice. Each has their specific advantages.

I'm not convinced by a few of these arguments.

Neither Nikon nor Canon have explicitly commited to APS-C specific lenses. With Canon we have the EF-S mount, and thus a very limited range, and Nikon have arguably released just one DX lens that could feasibly be aimed at the pro market (crucial to either brands long-term kudos and success), the Nikkor 17-55/2.8 - a fine lens indeed. This suggests to me that neither manufacturer are entirely convinced of the APS-C as the de facto system fo the future. I expect Nikon to release a FF body in 2007, and 2008 at the very latest. Extra FOV equivalence with telephotos notwithstanding it's hard to see any area where APS-C sensors outperform FF and I don't see that changing.

There are, to my mind, two battlegrounds where the fight for sales over the next 2-3 years will take place - noise and dynamic range. Canon currently lead in the first, and, with the 5D and 1Ds, the latter (although things are far closer here). Only Fuji can lay claim to superior DR and to date this has been at the expense lousy bodies (possibly to change with the S5, but it remains to be seen whether they can sort the noise issue and retain the speed of the D200 donor body). I have yet to see anything that suggests that APS-C can offer more than FF in these two areas.

Time will tell. I read an interesting comment from Nikon guru Thom Hogan last week over at DPR:

Poster says:

> my guess is there will never be, because for Nikon
> life does not depend upon FF, not even for their pro DSLRs.

TH replies:

Sorry, but I'll disagree. If we learned anything this year, we learned that the megapixel game ain't over. The Nikon pros are already underpixeled vis-a-vis the competition, and I personally don't see how Nikon is going to squeeze more quality pixels into APS--I already avoid ISO 800 and above on my D2x, am I going to have to avoid ISO 400 and above in the future?