Full Frame vs Crop: The real truth about extended reach

jase1125 wrote in post #14710544
Yes his math is wrong and yours is correct. In my tests and those of others demonstrate there is an advantage of resolving more detail with an 18MP crop sensor versus cropping a FF 21MP sensor. It isn't groundbreaking, but it is there at lower ISOs. Of course one needs to sharpen the 18MP images a. It differently to pull that detail out.

Yes, the 18mp APS-C should have higher resolution due to higher pixel density.

The tests between my 5d2 and T2i show the APS-C has a slight edge in resolution. Not much, and as you said, isn't groundbreaking, but it's there.

Forget the math. Look at the logic. Larger sensor is better, so all (consumer) cameras will be FF in the near future. This logic is so full of holes you could strain spaghetti with it. If bigger is better, I guess camera size and cost have instantly become irrelevant. Size and cost will ALWAYS be relevant. Each photog has a list of priorities, and buys the right camera for him(her)self. If IQ were the ONLY thing that mattered, we would all be shooting 8"x10" mega-frames with a million megapixels and paying $400,000 for each camera, which by the way, would weigh 40 pounds. Some people want a cheaper camera, some want a smaller camera. Don't even get me started on the, "OP was referring to DSLRs." DLSR can be made with 1/2.3" sensors or 4"x6" sensors. What the OP was referring to was the inherently better quality of larger sensors. Granted. My point is that there are other considerations. The proper way to test logic is to carry to extremes. If it doesn't make sense when carried to extremes, it doesn't make sense. The original post here is completely meaningless.

sambarino wrote in post #14710674
The original post here is completely meaningless.

Indeed. While I always try to seek the truth, I am continually wary of "real" truth.

The only way to make an argument that any camera is better than any other camera is to limit the comparison to some subset of features or other considerations. Thankfully, Canon and other camera makers realize this, and continue to produce variety in their offerings.

The real truth about the "Magic" of full frame sensors...

Math errors.

Sheesh.

Interesting discussion very thought provoking and you can learn from this post. Some people wont fast 8fps 7d or full frame 5d series. For me fast matters so 7d.

Tim

Forgetting for now the bad math...What is your point? Are you saying that by spending 5 times as much for a FF and then cropping it you get the same picture as the less expensive camera?

MotorPro wrote in post #14711776
Forgetting for now the bad math...What is your point? Are you saying that by spending 5 times as much for a FF and then cropping it you get the same picture as the less expensive camera?

I think that was the intent: that by using a big MP FF camera you can emulate the "reach" of a 18.1 MP cropper by literally cropping the image, and also have the versatility of the FF when you want it. You can't yet - you lose too many pixels, as has been pointed out.

I too want a FF camera, but not because it is "better" (that's subjective), but because it is different, and will offer up different FOV possibilities for all the EF lenses I have. A 5DIII or 1DIV will do fine, but I'll settle for a 5DII.

I also want a better-performing cropper. The 7D is pretty well there, I'm hoping the much rumored 7DII will be just what I'm hoping for: a 7D with more than 10fps, articulated rear display (very handy on my T3i), ISO out to 6400 (not noisy) and beyond, and down to 50, focus points from 5DIII, etc.

For now my T3i does me well enough.

shinksma

@ stumbows- your math obviously blows, and your reasoning skills don't seem that much better.

Simply put, the ADVANTAGE of the crop over the full frame is the amount of pixels on target- especially when you cannot fill the frame with a full frame body. A good example of this would be shooting the moon with 400mm of focal length, and trying to maximize the amount of detail captured - in essence, making the moon as large as you can without interpolating made up data. Because you cannot get it to fill the frame with either a full frame nor a crop body- it's a good example. With a 21mp ( 5D II ) and a 18mp crop ( 7D ), the advantage to the 7D is that there are approximately 2.2 times as many pixels comprising the moon itself. Roughly. If you look at 100% crops- of the same features on the moon- you will readily see the difference. Using the same comparison using a 5D3 ( 22mp) and a 18mp crop (7D ), the advantage drops- by a little bit- to about 2.1 times as many pixels on target. That's how you see the advantage.

True- you could negate MOST of the advantage of a crop by slapping on a 1.4x TC on the full frame- absolutely true- but then you could also slap that same 1.4x TC on a crop to get it to have the same advantage. And with a number of lenses out there, slapping on a 1.4x TC usually could mean losing AF- at least for most of us- regardless of whether it is on crop or full frame ( non 1D ). If you aren't going to compare equally- apples to apples- then it's not a comparison- is it? I can throw a 500mm lens on a crop and a 800mm on a full frame- but which did I pay more for ? Well, for the full frame- not only did I pay more for the lens, I also paid more for the body as well. Even if you go with the 1.4x TC route- the only Canon TC that they are apparently selling new now- is the mark III- which is about $450. So, if you compared a 60D costs using a 500mm lens, and a 5D II with its great autofocus system- the same lens, and a 1.4x TC- it's still costing you an extra $1500 to get there- and yet- you are still a little shorter. But for one thousand dollars less- with that same 1.4x TC- on the 60D, I would have the equivalent of 1120mm fov over the 700mm FOV that you would get on that 5D II !. And even after all of that- if it comes down to you still cannot fill the frame with the full frame, I can crop more with the crop body all because I still have more pixels on target.

Is it possible to get the title edited for this thread; it's kind of misleading.

It should be RE: Full Frame vs Crop: What I thought I knew, and well, it turns out that it was not...

something like that.

wayne.robbins wrote in post #14714125
Simply put, the ADVANTAGE of the crop over the full frame is the amount of pixels on target

Simple, yes. It's simply wrong.
What you have described is the advantage of a higher density sensor over one of lower density. Sensor size is not a factor, other than by coincidence.

xarqi wrote in post #14714716
Simple, yes. It's simply wrong.
What you have described is the advantage of a higher density sensor over one of lower density. Sensor size is not a factor, other than by coincidence.

He's got you there, Wayne.Robbins!

http://www.extremeinst​ability.com/topic-full-frame.htm

xarqi wrote in post #14714716
Simple, yes. It's simply wrong.
What you have described is the advantage of a higher density sensor over one of lower density. Sensor size is not a factor, other than by coincidence.

Except that it is not a coincidence, in the sense that it was not some random choice to make crop sensors with generally higher pixel density than FF sensors. In the world we live in you do tend to get more pixels on target with actual crop cameras than you do with actual FF cameras of the same generation.

@xarqi- once you take a single sentence out of context or remove all other references- yep- it boils down to that. But the OP's statements were about 5D II / 5D III and in comparison to a 7D. So, until you can get plug in sensors for the Canon DSLR line- yep- one has to assume that a 7D uses a 18mp APS-C sensor and a 5D II/5D III uses a full frame sensor in the 21/22 MP range. And then at that point- yes- you win thru pixel density. The OP's statements about throwing in a TC to make things equal- well- if you could stick a TC on a 5DII with a certain lens and use it- you can certainly do the same with a 7D, for example, and end up with more usable pixels. I know, everyone talks about the clarity of a full frame pixel - but it's still just that- a pixel.. Granted that what he says may make sense if you can fully frame the full frame using a TC- with what the desired outcome is- then what he says may make sense. If you are still short or focal length limited- then my point is why would you not leverage a modern crop sensor's advantages of higher pixel density- and get more pixels on target ? Because larger dots from full frame are better ? It's a pixel. Basically- a dot. Ridiculous to believe a dot or single from a full frame camera is better than a dot or single pixel from a crop camera. But if you are into just arguing semantics- well, I probably have better places to waste my time.

@sambarino. Will all DSLR's be FF ?
Lose the APS-C format cameras- and there goes all the sales of EF-S lenses. The alternatives- third party glass and EF glass- most of which is L. Pricey alternative. OK, some will bite the bullet and buy into EF glass- but many more will walk away. Good for Canon's pocket book ? Nope.

Entry level kits- like the T3, T3i, T4i, etc. This is where most entry level DSLR users are buying into. Without cheaper entry level cameras- most would be relegated to buying either used or none. A lot that fall into this category don't ever buy another lens- or if they do- they buy one- like a 55-250. Most consider flash- to be onboard flash. One or two kit lenses and perhaps a flash- for most- but not much beyond that usually. As far as buying used, the last time I checked- Canon does not make money off from Sam selling Pete a used camera. OK, sometimes sales of a used camera does make it into Canon- indirectly - because someone is upgrading. How about those that aren't ? Or those that are switching flavors ? Nope, it makes Canon no money in those cases either. What would a FF entry level kit look like ? 18MP full frame, with a 24-105 lens on it. A t3i kit- with a 18-55mm ef-s lens- is currently around $750. A lot of people scrounge up to be able to buy something like that. The 24-105- new- goes for about $1050 today. So, Canon would have to sell a body and lens for less than it sells the lens today??? Or develop a cheaper EF lens to put in kits..

EF glass. Perhaps you believe that EF glass is going to get cheaper. From what I've seen lately- it's not really the case. Have you looked at the new price on a 24-70 that you can purchase and get shipped now- and the newer version that is being delayed ? Good news is that older EF glass will be worth more- bad news- Canon does not make money off from used lens sales either.

Development: If full frame only was planned for the near future- why would Canon be developing EF-S glass still ( like the EF-S 18-135 STM's ) This in itself tells me that Canon is planning on keeping EF-S around for a while. Otherwise, you'd be seeing a 24-105 IS L STM (mark II ) lens instead.

Wayne, perhaps you haven't notice the preponderance of EVIL cameras on the market today, or heard the rumors of Canon likely releasing one soon. The EVIL format is mostly eating into Rebel sales. Sony has one with an APS-C sensor. It is rumored that Canon may also use an APS-C sensor in one of theirs. Sensor size may be one of the few things to distinguish the two line-ups. Meaning a reduction in the number of APS-C DSLRs and an increase in the number of FF DSLRs. Of couse, that is all just a theory. . . .