Practical Discussion on Full Frame Sensors

[Garbz]

I've heard a lot of talks about Full Frame vs APS sensors. Most of them while presenting a valid technical point have little impact in practical terms. I am wondering why would you want a full frame sensor, and there's a few arguments that I have heard.

Argument 1: No crop factor
Ok valid argument. Especially for people who use fisheye or other extreme wide angle lenses. Doesn't really affect me much since I am more inclined to want a 300mm lens than a 12mm anyway. Also for every shot where 18mm (27mm on my camera) isn't enough I am normally in a position to make a perfect panorama anyway.

Argument 2: Less Noise, more light etc.
This holds true in theory only. The sensors is part of a larger system where noise floor is determined not by the sensor technology itself but to the large part what's underneath it, like the layout of the amplifying transistors, the datapath used during readout etc. The D200's CCD sensor IMO has less noise than a 350D's CMOS (ok comparing apples to oranges) but it is the same thing as I hear in that debate.
So the other thing is pixels size. Larger pixels = more light. That only holds true assuming there's no technical advances made in the photo sensors themselves. After if the original premiss is true than in theory the Nikon D50 would significantly outperform my D200 noise wise (6mpx instead of 10 on the same sensor). This argument seems to be the reason people often recommend the Canon 5D (full frame = better) but does that mean the Canon 5D has a better sensor than the 1DMkIII? The photos I have seen say otherwise.

The debate often rears it's head in various Canon vs Nikon debates. Some say it is a "bad" move by Nikon to further develop the NikonDX sensor and build lenses for a sensor rather than take the far more expensive (reads economically sane) route of producing larger sized, lower yield sensors for standard 35mm lenses.

So someone, convince me. Why do we need 35mm sensors? Clearly the SLR world is crunching on just fine (constant improvements noise and qualitywise) with the much more economically produced APS sized sensor. If you don't like economics buy a Hassleblad

 

[Garbz]

Ok I just heard another good point. The fact that because the smaller sensor actually crops the centre of the lens you are using only part of your lens. Ok so it is the best part, and the same arguments as tele-converters apply here. But this assumes that you are using a 35mm lens, and not a DX Lens on a Nikon SLR or an Olympus lens designed for their 4:3rds sensor, which both are optimised to the smaller sensor. So from a technical stand point this is a lens based dilemma not a sensor issue.

 

[Mike_E]

Hi Garbz, you are preaching to the choir here. Who really cares as long as the resolution is the same (line pairs, color density, dynamic range- all of it).

Did any one think that if the tech gets right then it won't be too much trouble to have a stereo camera the same size as a DSLR. But not if you have to use a full frame senser.

This of course would depend on printing technology but 3-D portraits and action shots of the same quality as what we are shooting now. That is going to be something to see!

mike

 

[ksmattfish]

I prefer to compare print quality rather than adding up megapixels, so I don't really care what the numbers are or sensor size is, as long as the photos look good. I also think that the technology is going to change a lot in the next 2 decades. There are people working on one pixel sensors; I don't know what size they are. Who knows whats around the corner, but I bet it's smaller and more powerful. If people are willing to pay for it, making the sensors bigger is an easy way to get more quality out of the same technology.

On the other hand, lens technology is not advancing as rapidly as sensor technology. The smaller the format the more important lens quality becomes. You can get great quality photographs from a mediocre lens on medium format film, try the same lens on 35mm and it doesn't do so hot, and on an APS-C DSLR it's a lemon.

I like a bigger sensor, because that usually means a bigger, brighter viewfinder. The 5D is a joy to use after peering through 20D viewfinders for 3 years. They need to come up with a way to make bigger, brighter viewfinders not limited by the size of the sensor. I want something like a Pentax 67II viewfinder; now that's big and bright!

If you don't like economics buy a Hassleblad

I sold my Hasselblad 500 c/m, and bought an EOS 5D. Hassys are wonderful cameras, but like a lot of other brand cults, kind of overrated. Every medium format SLR I've ever used has been able to make just as nice photographs. I had the brightest screen available installed in my 500 c/m, and it was dark and hard to focus compared most others I had used. It was like being in a dark room compared to my P67II.

The sensors in the some of the medium format backs are sized slightly less than 4cm x 5cm, and match or beat 4"x5" film in terms of resolution. 4x5cm is barely bigger than 35mm format. That size sensor should fit into a body smaller than a 6x4.5cm SLR. If they could make them affordable it would be pretty cool. I bought my first digital camera (Kodak DC-50) about 15 years ago for $1500; it's max resolution was 756 x 504. Compare that to what you can get today for $1500.

 

[Iron Flatline]

There is nothing wrong with a smaller sensor, but let's not delude ourselves - there are no advantages either.

Digital SLRs were introduced to the market place before full-frame sensors were readily avaiable, or technically viable. On wide-angle lenses esp. the light at the edges of a lens wider than 16mm comes in at such acute angles that it is hard to capture it without substantial chromatic abberation.

In five years the APS-C format will only be alive for historical reasons. Again, this will be based on marketing, just like pixel-count was. Once full-frame sensors are available, the marketing people will push FF as a panacea. Then they will simply tally up pxiels on a big sensor versus the APS-C sized sensor, and will tell consumers THAT is better.

Don't over-invest in cropped formats, it's not worth it. You don't need to have an inferiority complex, but don't blow your paycheck on APS lenses - buy the kind that work for all sized sensors.

 

[astrostu]

Don't over-invest in cropped formats, it's not worth it. You don't need to have an inferiority complex, but don't blow your paycheck on APS lenses - buy the kind that work for all sized sensors.

Definitely.

 

[Garbz]

I'm not quite sure it will pan out like that but I guess we'll see when the time comes. APS-C is still far more economical and you get significantly higher yields from them. Mind you for all I know manufacturing could change to get 100% yield of every wafer which would mean that full frame sensors dramatically drop in price.
ksmattfish that is a good point about the lens quality vs size. Bigger lenses are easier to manufacture. The trend still seems to be going for small size though and as glazing technology improves for compact cams the advantages will be brought to SLRs too, mind you then full frame have an even bigger advantage.

It seems I may be preaching to the choir here. I expected less of people here I am just tired hearing people rant about how good their 5D is because of it's full frame sensor. Just say it like it is. The 5D is a great camera regardless of it's sensor.

 

[hyakuhei]

Well, my fiance soothingly reasures me that size doesn't matter, I'm inclined to believe her

 

[darich]

I upgraded from a Canon 20D to a 5D a few months back.
The increase in resolution is pretty good - 8.2 up to 12.8mp but the quality is different.
I use the same lenses on both cameras (listed in my signature) and the difference in quality is amazing.
The 5D images almost have a 3D look about them - they look much more like slides than digital images.
I've also shot accidentally at ISO1600 in broad daylight. The noise on the images is amazingly low - the 20D comparable level would probably be 800. And the 5D has many more increments in the ISO than the 20D. I can use 50, 100, 200, 400 etc as the 20D can but there are probably around double the amount of settings to choose from because i can also use 1000, 1250, 640 etc.

 

[fmw]

The reason is very simple. I want it to be able to use the excellent wide angle lenses made by Nikon and get all the available angle of view. Panorama is a different thing. Wide angle photography is normally done up close to provide a wide angle perspective. Panorama has nothing to do with perspective, only coverage. One is not a substitute for the other. Not even close. Wide angle photography, apparently, isn't common or popular these days. I think the reason is probably the APS sensors. However, I really like wide angle photography. For the most part, it is what I do. I want a 35mm sized sensor for that reason.

 

[Don Simon]

I'm very happy with the results from "APS" or "cropped" sensors. But I'm reluctant to invest heavily in lenses designed for the smaller sensors; I don't know that larger sensors will become the standard, but they might. Also I still like to shoot 35mm film but that's another matter. My main problem with the smaller sensors is basically the same as FMW's... the smaller sensors don't seem to make more economic sense when you're looking at wide-angle glass.

 

[Christie Photo]

The reason is very simple. I want it to be able to use the excellent wide angle lenses ... and get all the available angle of view.

BINGO!

I have a 17-40, and I need to get 17mm... not 24mm.

Pete

 

[Garbz]

good point fmw I completely forgot about perspective distortion. Very good point indeed. In fact this is by far the best logical point I have heard on the argument. Ok so it has limited appeal but I can see where it comes in.

darich the point is the 5D is a good camera, but is that just because of a large sensor? Will the 1DMkIII look worse? Or the Nikon D2Xs for that matter? No.

 

[ksmattfish]

There have always been multiple formats. Is a photo better because it was taken with a 4x5 view camera instead of a 35mm SLR? There are always going to be folks that say bigger is better; sometimes it is, sometimes it isn't. In the end it's going to be the photographer and the subject matter that are going to determine if the photograph is any good or not.

 

[darich]

darich the point is the 5D is a good camera, but is that just because of a large sensor? Will the 1DMkIII look worse? Or the Nikon D2Xs for that matter? No.

I don't know how the 5D compares to the 1D MKIII - i've never seen comparison shots.
There may well be a different sensor in both cameras which makes any comparison pointless.
I'd bet the 5D looks better than the Nikon because of the full frame though and not because of a Canon v Nikon bias.

I can see what you're arguing but it looks like it's heading down a "this camera is better than that one because it has full frame".....and not "full frame is better because........."

Personally, i feel the shots from my 5D are far superior to the shots from my 20D. I mentioned the lenses so that no one could argue they were the cause or reason.
Until you've seen a good shot on a 5D it's difficult to explain but the shot looks layered and looks like it has depth. The 20D is a great camera and while the shots were excellent, i feel the 5D is superior.
It's a larger step in quality from my 20D to my 5D than it is from my 4mp Canon A85 to the 20D - So i know it's not the resolution.

Full frame adds quality and depth to images. So it's an increase in quality.