Could someone explain FF advantage ?

[Wulifou]

Hi,
sorry if this is a recurrent question, but could someone please help a beginner understanding following hot topic :

FF seems to cause alot of passionate posts, as far as I read partly because of Pentax announcement not to follow the current ff trend (or at least not immediatly)
But I haven't found so far some clear explanation why FF should be so much better (or worse).
As far as I understand it, following things change :

a) you loose the x1.5 crop factor. That's great for those with FA wide lenses and sucks for those who are into wildlife and sports.
b) you cannot use your DA lenses anymore. If that is true, than it's definitely a bad point.
c) You gain a lot of MP and resolution but suck at higher ISO (Sony 900) OR
d) You keep around 15MP and go up to amazing ISO performance (Nikon 700)

I get the resolution/ISO part, but is there something else that initiated the FF development ? Apparently, there is a great demand for FF, but I honestly don't see what difference it will make. Does someone have experience with Full Frame cameras he/she could share ? thx a lot

[Venturi]

There is a pretty good writeup on the pros/cons of both FF & APS-C linked here: http://www.pentaxforums.com/forums/369168-post1.html

The way I'm approaching the issue is to view 35mm (full frame) and APS-C as two different formats; the same way that large and medium formats are different; and the fact that "full-frame" lenses work on APS-C cameras is merely a happy coincidence.

[RBellavance]

Originally Posted by Venturi

The way I'm approaching the issue is to view 35mm (full frame) and APS-C as two different formats; the same way that large and medium formats are different; and the fact that "full-frame" lenses work on APS-C cameras is merely a happy coincidence.

That's probably the sanest way to look at this whole thing. It happens to be my outlook as well

[Wulifou]

Originally Posted by Venturi

There is a pretty good writeup on the pros/cons of both FF & APS-C linked here: http://www.pentaxforums.com/forums/369168-post1.html

Thx a lot ! Very interesting article, I wasn't aware of the DOF changes that implied.

[Pål Jensen]

Originally Posted by Wulifou

a) you loose the x1.5 crop factor. That's great for those with FA wide lenses and sucks for those who are into wildlife and sports.
b) you cannot use your DA lenses anymore. If that is true, than it's definitely a bad point.
c) You gain a lot of MP and resolution but suck at higher ISO (Sony 900) OR
d) You keep around 15MP and go up to amazing ISO performance (Nikon 700)

Most of you conclusions are wrong.

a) For the same or similar pixel density an FF camera will give you the exact same 1,5X crop if you want it. Or not if you don't want it. You loose nothing but gain flexibility.
b) You can use your DA lenses but in cropped mode.
c) No. An FF camera will have 50% better noise performance than an APS camera with the same pixel density at the same output sizes.
d) True

[Wulifou]

Originally Posted by Pål Jensen

a) For the same or similar pixel density an FF camera will give you the exact same 1,5X crop if you want it. Or not if you don't want it. You loose nothing but gain flexibility.
b) You can use your DA lenses but in cropped mode.
c) No. An FF camera will have 50% better noise performance than an APS camera with the same pixel density at the same output sizes.

for a) and b) : right. I completely forgot the possibility on FF cameras to switch to cropped mode. Thx for correcting.
for c) : that's interesting. The few examples I saw made me believe noise was more important (say around iso 1600), but it's true that the pictures I saw were copared images between severel FF cameras, not FF against APS-C format. So thx again

[jeffkrol]

Originally Posted by Pål Jensen

Most of you conclusions are wrong.

a) For the same or similar pixel density an FF camera will give you the exact same 1,5X crop if you want it. Or not if you don't want it. You loose nothing but gain flexibility.
b) You can use your DA lenses but in cropped mode.
c) No. An FF camera will have 50% better noise performance than an APS camera with the same pixel density at the same output sizes.
d) True

I'd read a bunch of this thread in regards to your c)
Re: A pixel density question: Nikon D300 - D100 Forum: Digital Photography Review

Larger sensors w/ same pixel count will be one stop less in noise max.
I would answer somewhat differently. The reason why the D700 has over one stop improvement in image quality over the D300 is that the sensor is over twice the area, and so collects more than twice as many photons. It's not how many photons individual photosites are collecting, it's how many are being collected over the entire sensor -- and it's the bigger sensor that is responsible. A FF sensor filled with the same size pixels as the D300 would also have over a one stop advantage in noise over the D300.

Pixel density is not and never has been the issue for noise. It's sensor size, despite DPR's attempts to infer otherwise.

http://theory.uchicago.edu/~ejm/pix/.../noise-p2.html

[Pål Jensen]

Originally Posted by jeffkrol

Larger sensors w/ same pixel count will be one stop less in noise max.
[/COLOR]

Yes, and one stop = 50%

[*isteve]

Originally Posted by jeffkrol

I'd read a bunch of this thread in regards to your c)
Re: A pixel density question: Nikon D300 - D100 Forum: Digital Photography Review

Larger sensors w/ same pixel count will be one stop less in noise max.
I would answer somewhat differently. The reason why the D700 has over one stop improvement in image quality over the D300 is that the sensor is over twice the area, and so collects more than twice as many photons. It's not how many photons individual photosites are collecting, it's how many are being collected over the entire sensor -- and it's the bigger sensor that is responsible. A FF sensor filled with the same size pixels as the D300 would also have over a one stop advantage in noise over the D300.

Pixel density is not and never has been the issue for noise. It's sensor size, despite DPR's attempts to infer otherwise.

Noise, Dynamic Range and Bit Depth in Digital SLRs -- page 2

Not true. If you measure noise as standard deviation in RGB value on a single colour patch, then sensors of equal density will receive the same photon count per photosite and have the same noise. The only difference is that you can enlarge the image from the bigger sensor more before its visible, or reduce it to the size (in MP) of the other and reduce it but this does not mean there is less.

Its the same as ISO100 35mm film and MF film. The grain is the same it just looks worse at the same print size on the smaller negative.

[Blue]

[Class A]

Originally Posted by Pål Jensen

a) For the same or similar pixel density an FF camera will give you the exact same 1,5X crop if you want it. Or not if you don't want it. You loose nothing but gain flexibility

That's only the case if the pixel count goes up accordingly.

Originally Posted by Pål Jensen

c) No. An FF camera will have 50% better noise performance than an APS camera with the same pixel density at the same output sizes.

Only if you accept thinner DOF.

Anyone really interested in an in-depth comparison of FF vs APS-C should read Joseph James' essay on comparing sensor formats.

I personally learned from it that FF is less demanding on lenses (with the exception of extreme corners in particular with wide angle lenses). FF glass can be slower and less sharp and will still give the same IQ as APS-C glass.

Joseph doesn't mention other downsides of FF technology, like the bandwidth requirements (in terms of both memory and processing speed demands), but I guess it will just be a matter of time only until the associated costs of FF (also the monetary side) will no longer be show stoppers.

[Wheatfield]

To me, it's about reduced high ISO noise, banding and the like. I have it on good regard that you will also see an increase in actual resolution (with the D700/D3 approach of keeping pixel counts reasonable).

[pasipasi]

Well I'd love to use my old lenses on a FF dslr. I don't mind losing the extra 1,5x from the tele end to get wide angle back from my 28mm and 35mm lenses and my 50mm would be normal again.

[RiceHigh]

Originally Posted by Wulifou

Hi,
sorry if this is a recurrent question, but could someone please help a beginner understanding following hot topic :

FF seems to cause alot of passionate posts, as far as I read partly because of Pentax announcement not to follow the current ff trend (or at least not immediatly)

Pentax is not following the FF trend just because they are just unable to get a ticket for the FF train!

But I haven't found so far some clear explanation why FF should be so much better (or worse).
As far as I understand it, following things change :

No problem, I reply point by point as follows:-

a) you loose the x1.5 crop factor. That's great for those with FA wide lenses and sucks for those who are into wildlife and sports.

Yes, generally speaking.

b) you cannot use your DA lenses anymore. If that is true, than it's definitely a bad point.

Yes, a DA lens, which has a smaller projected image circle, practically is not usable on a FF DSLR body, just see my this recent experiment:-

RiceHigh's Pentax Blog: DA 18-55 on Full Frame

But, it is not a "bad point", not even "definitely. Definitely, it is a very important point, instead, for all those users who own and use their old film glass. Do note that film glass on small sensor cropped factor APS-C 1.5X DSLRs is just a bad idea, even for tele-photography as resolution is lost optically.

c) You gain a lot of MP and resolution but suck at higher ISO (Sony 900) OR

Nope. This is not correct. DPR found that the noise performance of the A900 is worse at ISO 800 just for that particular body, not in general case - just because the pixel density is too high and thus physical pixel pitch size is too small (it has 24.6MP!). So, same case applies for APS-C 1.5X DSLRs when the pixel count just at 12MP (not even more! AS APS-C is just of 42.4% of the area of a FF sensor and so does the physical size of a pixel for receiving light if the pixel count is the same)

d) You keep around 15MP and go up to amazing ISO performance (Nikon 700)

Ditto. The noise performance at 15MP for a FF camera is amazing with good details and resolution retained even at high ISO without the expense of more noise. Same have never happened so far for APS-C DSLRs. Even though when technologies advance in future for an APS-C DSLRs to have acceptable performance at 15MP, by that time a FF DSLR at 30MP will have the same image quality then. So, the FF will always WIN![/QUOTE]

I get the resolution/ISO part, but is there something else that initiated the FF development ? Apparently, there is a great demand for FF, but I honestly don't see what difference it will make. Does someone have experience with Full Frame cameras he/she could share ? thx a lot

There are still other differences you haven't noticed yet, I think. For example, FF DSLRs have more freedom on choosing shallower DoF and have better 3d feel. FF DSLRs are more efficient and optically optimised than those APS-C DSLRs which designed based on a cropped 135 film SLR form factor. In fact, the APS-C DSLRs which kept the back focus register distance are the worst thing to do as the lens and body made is not much smaller and lighter but actually the light received is only at 42% (which is the case of Pentax DA lenses).

For what FF photos look difference in IQ and 3d feel, judge yourself for my "junky" sample photos in the below link, if interested:-

RiceHigh's Pentax Blog: Sample Photos of Full Frame Fisheye and 43 Limited on 5D

[RiceHigh]

Originally Posted by Blue

The "Shit" is you are being so rude in making a totally useless and unhelpful post in responding to an FAQ which is generally interested and asked by many beginners (and I think they need to know too).