FF vs crop to clarify

o.k. so I know this topic has been beat to death, but I just want validation from experts that my understanding is correct, I'm shooting for more DOF and better detail thats why just a P&S wont work, so my limited understanding is the cropped cameras have wider DOF, FF has better detail and better detail at high ISO, if one needs more DOF one can address this in a FF camera by increasing the ISO and aperture, this will give a result that may be better than the crop even though ISO is higher, because FF sensor is better even at higher ISO number, in a studio under controlled light circumstances one could get a superior picture with wide DOF by adding more light, the ability to adjust DOF due to the FF superior light sensitivity would imply that if they could take photos ata higehr frame rate then they would be superior to the crop, am I right wrong or overly simple

Regardless of whether you use a full frame or crop sensor, the lens generates the same image circle. The "cropped" sensor just picks up less of that same image. In both cases, assuming all the same settings and distance from the subject, DOF will be identical. See the image below on the crop v. full frame field of view.

That being said, you would have to change your focal length or distance from the subject on one camera to be able to generate the exact same image on both sensors. That is where your DOF is going to change. It's not the sensor which impacts DOF, but the changes which need to be made in order to get the exact same image or field of view due to the difference in sensor size.

I hope that makes sense.

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that's such a helpful picture. Should be posted in every crop vs ff thread. =)

Agrees

Larger sensors don't perform better just because they're bigger in area. Pack pixels as tightly on a FF chip as on a APS or compact chip and you'll get all the same image problems. The operative point is that the larger surface area allows each individual receptor to be bigger. A larger receptor gathers more photons and generates a stronger signal which needs less amplification, so noise issues are reduced.

So, whatever the size of the chip,the key factor is receptor pitch - bigger pixels are better

A few things:

1.) P&S cameras, with their tiny sensors, have incredibly deep depth of field. Why? The image posted by SoCal69 explains it well ... the focal lengths required for 'normal' photos on small-sensor cameras are very wide. Very wide = very deep DOF. So if all you're after is DOF, get a P&S

2.) Larger sensors can deliver better quality images because, as Chris says, they collect more light. This becomes increasingly obvious as ISO increases. You got that right

3.) DOF is a function of aperture, focal length and distance from subject. It has nothing to do with ISO "per say". So you can stop down your aperture to increase DOF, but you'll lose light, so you'll need to either slow down your shutter speed or increase your ISO to get the same exposure. Or in a studio, you could just increase the power of your strobes. (Bear in mind that shutter speed is irrelevant when using strobes as primary light sources.)

I guess most of what you've said is correct, but your flow of logic seems to be:

Smaller sensor -> large DOF (but cruddy little camera, no detail, yuk)
Larger sensor -> less DOF (but better ISO performance makes up for it by letting me stop down my aperture lots)
Big camera -> studio flashes (which let me stop down my aperture lots without increasing ISO ... at least I think that's what you said?)

And I'm not quite sure where you're going with that.

In the end, I think you'll find full frame cameras can deliver plenty of DOF without even needing to increase ISO -- just by stopping down aperture and making sure your shutter speed doesn't drop too low. In studio environments, you should be able to shoot ISO 100 and get very high DOF (if your strobes are powerful enough).

Oh, and you don't need FF to get amazing detail -- 1.6 crop cameras (like my 30D's) do a marvellous job, unless you need REALLY big prints.

Hope that helps.

SoCal69 wrote in post #2851130
Regardless of whether you use a full frame or crop sensor, the lens generates the same image circle. The "cropped" sensor just picks up less of that same image. In both cases, assuming all the same settings and distance from the subject, DOF will be identical. See the image below on the crop v. full frame field of view.

Your 4/3 view is not for all 4/3. That is probably the size Olympus uses on their dSLRs, 2x factor. There is no reason the 4/3 ratio frame couldn't be enlarged to touch the edges of the 35mm image circle to become full frame.

mogearnotalent wrote in post #2850987
so my limited understanding is the cropped cameras have wider DOF, FF has better detail and better detail at high ISO, if one needs more DOF one can address this in a FF camera by increasing the ISO and aperture, this will give a result that may be better than the crop even though ISO is higher

First you need to know what a sentence is. Your whole post was one run on sentence.

The better option is to use low iso, small appeture, and a tripod with cable release and MLU instead of high iso. high iso will work in a pinch, but you'll get better stuff when you do it properly with a tripod.

chris clements wrote in post #2851733
- bigger pixels are better

Surely, there is an optimum size. That is, bigger pixels are better, to a point--then what they provide in terms of s/n ratio they give up in resolving-ability.

Hellashot wrote in post #2852612
First you need to know what a sentence is. Your whole post was one run on sentence.

The better option is to use low iso, small appeture, and a tripod with cable release and MLU instead of high iso. high iso will work in a pinch, but you'll get better stuff when you do it properly with a tripod.

What makes this technique "proper," or "better" than the suggestion of the OP? It seems that many factors the op did not mention would drive what the better technique would be.

BillMarks wrote in post #2852837
Surely, there is an optimum size. That is, bigger pixels are better, to a point--then what they provide in terms of s/n ratio they give up in resolving-ability.

True.
I was a tad simplistic - you can of course reduce receptor size as long as you introduce commensurate improvements in your processing engine, and your overall pixel count isn't too great for the resolving power of the glassware feeding the chip.
Another presumption we should NOT make is that the manufacturers increase pixel count with each new model in order to to improve the image; they do it to move product. There are numerous instances where the successor is outperformed by its predecessor, the obvious Canon example being the G3 & G5.

Although thankfully it's starting to slow, the pixel race still goes on. So I'd suggest we'll never see receptors as big as the 5D's again.

Hellashot wrote in post #2852605
Your 4/3 view is not for all 4/3. That is probably the size Olympus uses on their dSLRs, 2x factor. There is no reason the 4/3 ratio frame couldn't be enlarged to touch the edges of the 35mm image circle to become full frame.

Yeah, kinda.
Although a 4/3 ratio sensor could theoretically be of any size, it could not be identical to a FF in ratio of vertical to horizontal, since FF=35mm=24x36=3/2 ratio.
You could have a 4/3 sensor the same height (24mm), but slightly narower (32mm), or one that is equal in width (36mm), but taller (27mm), but not one that is the "same as" FF.
But your point is well made, in that 4/3 is a statement of ratio, whereas 1.6 is a percentage of FF.

linarms wrote in post #2851795
A few things:

And I'm not quite sure where you're going with that.

Oh, and you don't need FF to get amazing detail -- 1.6 crop cameras (like my 30D's) do a marvellous job, unless you need REALLY big prints.

Hope that helps.

I guess where I am going with all that is this, being a gadgetaholic, I'm seeking justification to upgrade to FF in the future, in spite of the biggest issues for me as a photographer is I need more skill not more gear. Proof of my lack of talent is what I like.....large DOF--what most "artistes" say is the opposite of the advantage for FF. I'm trying to learn more all the time, the mega-pixel war goes on, life was simpler when I had a Nikon N90, i figured I had no need for a new camera ever, now I'm trying to duplicate that experience to be able to in the near future buy one camera and keep it for 5-7 years, and part of that is trying to convince myself that a FF SLR can do this by allowing me to use its adjustability to adapt to whatever circumstances arise. MY 20D works just fine, I admit I've used it in the full auto setting until learning more from this site, now I am getting into RAW. I am times frustrated, as even when I use aperture priority I never see the camera self increasing ISO, it seems to want to lower shutter speed first to address exposure.

chris clements wrote in post #2853108
True.
Another presumption we should NOT make is that the manufacturers increase pixel count with each new model in order to to improve the image; they do it to move product. There are numerous instances where the successor is outperformed by its predecessor, the obvious Canon example being the G3 & G5.

Although thankfully it's starting to slow, the pixel race still goes on. So I'd suggest we'll never see receptors as big as the 5D's again.

and thats one of the hardest concepts to grasp how more info/data sometimes is not better

Hellashot wrote in post #2852605
Your 4/3 view is not for all 4/3. That is probably the size Olympus uses on their dSLRs, 2x factor. There is no reason the 4/3 ratio frame couldn't be enlarged to touch the edges of the 35mm image circle to become full frame.

http://en.wikipedia.or​g/wiki/Four_Thirds_Sys​tem

I think that's why it wasn't labeled as 1.333x - 4/3 system originators have "stolen" the symbol 4/3