[stevebrot]

People don't use FF camera to gain a wider angle of view, there are lenses that give the same angle of view for both FF and aps-c cameras.

The main advantage is image quality, bigger sensor, more detail can be captured.FF kicks aps-c's ass, and medium format kicks FF's ass....

Shallower depth of field at the same angle of view, which I think is one of the most important factors.

You can also add:

• Less need for SR

The smaller sensor effectively amplifies camera motion. I can easily hand hold at 1/15s with my FA 77/1.8 on my 35mm film cameras, but would not dream of trying that with any of my 50mm lenses on the K10D without SR. I first noticed this with the tiny sensor on my Canon G2. I don't go anywhere with that camera without a tripod.

Steve

P.S. This is just my personal experience. I am sure someone will post something with diagrams showing why this should not be the case.

[cwood]

P.S. This is just my personal experience. I am sure someone will post something with diagrams showing why this should not be the case.

Ha ha. I usually just keep my mouth shut when I suspect some pixel peeping computer geek is going to try to counter my argument with a spreadsheet and a list of websites linked to other computer geeks who agree with them. Good for you for sharing your experience anyway . This whole DSLR thing has gotten a little bit too much "D" and not enough photography if you ask me.

For the OP. I would only go full frame (or medium format) for 2 reasons.
1. My intention was to make a GIANT poster or billboard or something that would benefit from having 24-50 megapixels.
2. High ISO performance. As has been mentioned larger receptors mean they have better light gathering ability.

The other differences like DOF make no difference to me. 55mm at 1.4 has plenty thin enough DOF on a crop sensor for my world.

Dynamic range tends to be better on FF but I don't think that has to do with the size of the sensor since a Nikon D3x has the same pixel density as a Pentax K20D but the Nikon has much better DR

[K-9]

Has there been any news of a FF Pentax??

[Marc Sabatella]

You can also add:

• Less need for SR

The smaller sensor effectively amplifies camera motion. I can easily hand hold at 1/15s with my FA 77/1.8 on my 35mm film cameras, but would not dream of trying that with any of my 50mm lenses on the K10D without SR. I first noticed this with the tiny sensor on my Canon G2. I don't go anywhere with that camera without a tripod.

Steve

P.S. This is just my personal experience. I am sure someone will post something with diagrams showing why this should not be the case.

I don't believe it would be the case, but I don't have diagrams :-). Every bit of logical mathematical background I have (*see below), though, suggests that shake is dependent on FOV and FOV only.

Thinking aloud:

Shake reduction works by moving the sensor to counteract this and therefore also needs to be proportional to FOV (hence the focal lengths on the SR menu). But the actual physical distance the sensor would need to be moved for a given FOV would actually depend on sensor size, I would think - smaller sensor, less distance. Less distance sounds like it's easier, but it also means you've got to be that much more precise about the movement. I'd therefore assume there is probably an optimum sensor size from the perspective of SR - bigger than that means the sensor has to move too much, small means it is harder to control the motion with enough precision. But I have no idea what that optimum would be.

* Regarding my logical and mathematical training: for some reason, this is reminding me of my greatest mathematical crisis from college, and that is when I realized that no matter how many zigzags you make while trying to approximate a diagonal line by using a series of alternating horizontal and vertical motions (eg, a "staircase" with smaller and smaller stairs), the total distance always remains the same. My intuition said it should approach the length of the diagonal as a limit as the numbers of steps approached infinity, just as the perimeter of a polygon approaches the circumference of a circle as the number of edges reaches infinity.

My experience is that issues relating to DOF and lens versus sensor resolution have the same potential to totally fly in the face of what seems logical to me at first. I have no problems believing my thinking about SR wouldn't turn out to also be wrong.

[attack11]

apparently one of the biggest hurdles for the a900 was the sr system due to the sensor size.

[kthung]

Equivalent FOV does not equal equivalent pictures.

https://www.pentaxforums.com/forums/pentax-dslr-discussion/61827-comparison-3...lots-pics.html

As mentioned earlier having to use a wider lens on an APS-C sensor will have a different Depth of Field as a longer lens on a FF sensor.

[Cosmo]

Marc's right, it's field of view that effects shake reduction, not focal length.

[stevebrot]

I don't believe it would be the case, but I don't have diagrams :-)...

I knew I could count on you Marc
I am with you in regards to the combination of mathematical knowledge and logic. FOV should be the deciding factor.

Consider the simple case:

• Subject is a 200mm wide horizontal rectangle at some arbitrary distance from the camera
• image is 2mm wide at the sensor plane on APS-C
• image is 3mm wide on FF (I really hate that term, FF)
• both images above are vertically centered on the sensor (angle of incidence is essentially zero)
• 2mm vertical motion at the sensor over some arbitrary period of time

Question: Is the relative vertical displacement of the image the same for each sensor? Logic says yes...

On the other hand, my experience has been that hand holding is much more difficult with the smaller sensors. Go figure.

...I have no problems believing my thinking about SR wouldn't turn out to also be wrong.

Ditto for me! The older I get the more I tend to get things wrong! It make my mind hurt thinking about these things. Hard to believe that at one time I scored high for spacial reasoning!

Steve

(Since logic and math are against me here, I am probably wrong...anyone with MF experience want to weigh in?)

[redpigeons]

Equivalent FOV does not equal equivalent pictures.

https://www.pentaxforums.com/forums/pentax-dslr-discussion/61827-comparison-3...lots-pics.html

As mentioned earlier having to use a wider lens on an APS-C sensor will have a different Depth of Field as a longer lens on a FF sensor.

I love this one!!

and the winner is.... the K1000 !!!

when Pentax will create a digital as good and as simple and as rigid as the K1000
it have to be 35mm thou no cropping

Pentax will be No. 1 again

[GerryL]

It's the fault of manufacturers 'coz they wanted to give us a reasonable or reachable price so they compromised..hence the APS-C and other small sensor kinds.
If it weren't for the manufacturers thinking of its consumers and the viability of their product in the market..to make money, then they would have only produced full frames in the first place.
It's all about economics and not actually how one is better than the other.
The advantage of one over the other comes as a consequence of economics..and on how you want to look at how the other is better over the other.
From the production side and market wise..the APS-C is better, that is also why there is more of it than FF (not unless you count film).
This is also the reason behind a lot of the P&S cameras that most plain Janes/Joes has or have.

[kenyee]

Three possible reasons:
- bigger sensor w/ usually bigger pixels = better high ISO and dynamic range (for wedding photogs)
- narrow DOF for better subject isolation (for portrait/model photogs)
- bigger viewfinder (for people who want a bigger viewfinder image...generally older photogs...sorry guys)

APS-C is better for
- people from P&S who are frustrated w/ narrow DOF because "some parts of the image are too fuzzy" :-)
- sports shooters who get the 1.5x multiplier to map the image into pixels
- people w/ less deep pockets

Even if Pentax went FF, I'd still keep an APS-C body as a backup...

[Venturi]

It's the fault of manufacturers 'coz they wanted to give us a reasonable or reachable price so they compromised..hence the APS-C and other small sensor kinds.

I have no proof, but my reading up on the history of APS format and the dawn of digital photography leads me to believe it had more to do with what Kodak and Nikon were doing at the time than it had to do with economics of sensor design.

Kodak was trying to push their new APS film format heavily at the time. It was to be the next generation of film photography with all types of shot data recorded with each frame and multiple aspect ratios (APS-C being merely one of them) including 16:9 and panoramic.
Nikon and Kodak "teamed up", sort of, on the first digital SLR which used a Kodak developed sensor (APS format no surprise) in a Nikon SLR body.
Nikon continued onward using APS for their digital R&D tagging it "DX format" and eventually came out with the D1 - and the world went "Ooooh ... Aaaahhhhh".
Kodak's digital projects, without Nikon's clout and I'm guessing R&D budget, never got enough leverage to really go anywhere.

I'm sure economics played a part in the early decisions to go with APS instead of 35mm, but I suspect it was Kodak's championing of the APS film format that was the real leverage in the early discussions.

[24X36NOW]

Dynamic range tends to be better on FF but I don't think that has to do with the size of the sensor since a Nikon D3x has the same pixel density as a Pentax K20D but the Nikon has much better DR

Actually, the D3X pixel density is closer to the K10D (about 10.29 MP APS-C equivalent). A FF equivalent pixel density would be 34.76 MP. The conversion factor for the 1.5 form factor APS-C is about 42%.

Even IF image quality was a complete wash, FF would be better simply by virtue of the nice big viewfinder; APS-C viewfinders pretty much suck. Don't believe it? Pick up a K1000 or an LX and look through the viewfinder, then pick up your Pentax dSLR. You won't need any further explanation. Larger formats will always have better image quality than smaller formats due to optics. When you put your PK lens on a dSLR, you're asking the lens to resolve the same details (assuming you frame an image the same way on an APS-C dSLR as you do on a FF dSLR or a 35mm SLR) to 42% of the size (roughly) that the lens has to resolve those details to on FF.

[Marc Sabatella]

On the other hand, my experience has been that hand holding is much more difficult with the smaller sensors. Go figure.

Smaller sensor = smaller camera (usually), and I think it's also conventional wisdom that too small / too light a camera is actually harder to hold still than a more substantial one (again, up to a point).

[stevebrot]

Smaller sensor = smaller camera (usually), and I think it's also conventional wisdom that too small / too light a camera is actually harder to hold still than a more substantial one (again, up to a point).

Yep, the Canon G2 is a pain to hand-hold and it may well be the weight factor. OTOH...my XR7 film cam is half the weight as my K10D and it hand-holds very nicely. OTOH...the XR7 has a famously smooth shutter release. (Maybe someone should cut off my other hand... )

In any case, I am willing to concede, barring good scientific evidence, that sensor size probably has little or no impact on blurring due to camera motion.

Steve