rcl285

I'm new to this forum, but started taking pictures some 60 years ago. I started with an Exacta SLR with a handful of lenses, but got derailed by the kids saying "why does it take so long to take your pictures?" About 15 years ago, my grown kids gave me a 1Mpixel Canon, and I was hooked on digital photography. From there I progressed through the digital ELF series, but became disillusioned with the delay from the time you pressed the button until the picture was snapped. It's amazing how fast those grandkids move. One of my kids gave me a Canon Rebel 4Ti with a 18-135mm lens, and I am amazed with how flexible it is. Of course, that flexibility comes with a very thick manual.

From this group, I get the impression that a cropped sensor is inferior to a full frame camera. Since both cameras have the same number of pixels, the difference must be in the size of the pixels. Since the pixel size on a FF sensor is larger, the number of photons needed to get a signal is less. Does this result in a higher signal to noise ratio? Or to put it into different words, does it result in a better result at a given ISO setting?

Or, is the difference between a cropped and FF sensor camera really in other things, such as quality of construction, penta mirrors vs. penta prisms, or are there other differences?

clh3RD

Welcome. I'm sure you will get a lot of commentary because we have loads of techies. Your question raises one of my own. I distinctly remember reading in an "unimpeachable" source that bigger pixels contain more light than smaller ones.

amehta Loc: Boston

With two cameras with the same number of pixels, one is full frame (FF) and the other a crop sensor (APS-C), the pixel size is bigger and that does give better performance especially in low light and at a high ISO. With the Canon cameras, the FF sensor is about 2.5x the size of the APS-C sensor, so there are 2.5x as many photons captured by each pixel for a given exposure level, and a corresponding signal to noise ratio. At lower ISO levels, like 800 and lower, the difference is generally small to imperceptible. At higher ISO levels, 1600 and above, it starts to become more noticeable.

The other difference is that the sensor size affects the depth of field, and a larger sensor will allow for a shallower DoF with a given aperture lens. The situation and photographer's goals dictates whether this is good or bad: sometimes deeper DoF is good, other times shallower DoF is good.

amehta Loc: Boston

I would say bigger pixels capture more light than smaller ones.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

rcl285 - every camera has its purpose - there are many different sized sensors, starting with your phone, and ending with digital backs for 4x5 view cameras that exceed 200 megapixels. Generally speaking smaller sensors are more portable, offer great depth of field (great for lanscapes, not so good if you are trying to use shallow DOF to isolate your subjects), and generally low price. As you increase in sensor size, pixels "generally" get bigger, and as amehta pointed out, bigger pixels mean more light sensitivity. Which usually means better quality images at high ISO in low light. The question of one size being inferior to another all depends on how the image will be used.

Cellphone cameras are excellent for grab shots for posting online or sending in an email, and maybe making a 5x7 or slightly bigger. The cropped sensor camera can make an image up to 16x20 with excellent quality, and the full-frame camera can do 24x36 or bigger with great quality. This is the oversimplified answer - there is much, much more to this, including the pixel dimensions, print size, camera performance, portability, lens quality, etc etc. but each selection is a combination of trade offs. There is no one perfect camera for all situations for all users.

LFingar Loc: Claverack, NY

One of the most noticable differences between a cropped sensor and a full frame is your field of view. The cropped sensor in your T4i has a ratio of 1.6:1, same as my 70D, compared to a ratio of 1:1 for a full frame. You will see references to focal length differences between the two. For example, as you increase the focal length of a zoom your field of view decreases. With my EF70-300mm zoom the field of view is actually equivalent to 112-480mm on a full frame. Actual focal length times 1.6. This applies to all lenses, not just zooms. In short, you are getting a smaller picture area. There have been several good charts and illustrations posted showing the differences. The search function would probably bring them up for you.

Cdouthitt Loc: Traverse City, MI

I'll take my omd and arsenal of small lenses any day over ff.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Nice camera, the OMD. I love a lot about it except for the sensor size. How do images printed to 40"x60" look? It's the main reason I shoot a D800 FF. No comparison on large printed images. Great travel and amateur sports camera, though.

Onembz

I can't answer your tech question, but, would like to know how to get a great kid like that

Cdouthitt Loc: Traverse City, MI

I don't shoot 40 x 60, probably never will...not a pro (why ruin a hobby I love). 30" x 40" is as large as I usually go with my HP 5500uv printer...it's rather forgiving. I have done a 30" x 10' wide print from a 4/3 sensor, but it was a 5 shot pano. I also had two of my photos used on a billboard, but that's a totally different process and viewing distance.

D800 is nice, but the price of the body and lenses put it out of reach of most people, including myself, whom has a decent budget each year for camera equipment set aside. That and for hiking...uh, no thanks. It reminds me of hauling around that darned M240 Golf when I was in the Marines. I just went on a 6 mile hike with my gear, and didn't wince a bit with the EM1, 3 batteries, my 7-14, 20mm, 45mm, and flash packed into my tamarac sling bag.

Just a few of the results:
http://www.uglyhedgehog.com/t-186094-1.html

Morning Star Loc: West coast, North of the 49th N.

Who would ever want a 40x60inch print?
At 122 ppi from the D800, you'd better keep your distance from that print, or you can count the pixels.
Sensor size is NOT the be-all and end-all, like a crop-sensor you have to learn to use it. I have seen more bad photos from FF cameras than I care to think about.

I'm sorry, Gene, but your statement comes across as coming from someone who likes the latest, newest, bestest, most expensive toys, and I bet you've never even had an OM-D E-M1 in your hands, much less taken it out to take photos with.
Oh, I absolutely agree, it is a great travel camera. It also is a great camera to take portraits, or photos of professional show-jumping (Ian Millar, Beeze Madden level). I don't know how the camera would know the difference between amateur sports and professional sports.
One thing I do know for certain, and from personal experience: the micro 4/3 camera, with a 4/3 14-54mm II lens will give me tack-sharp handheld photos, at a resolution of 240ppi and a print size of 19 x 14 1/2 inches - and even that is larger than I ever want it!

Sorry, Gene, but belittling a camera, ANY camera, is not the way to make friends and influence people.

bkyser Loc: Fly over country in Indiana

I've had my photos from a D-200 cropped censor 10.1 mp put on the side of a bus. Unless you need photos larger than that, then I wouldn't worry about it. I shoot weddings all the time with a crop sensor camera. Do many large prints, and never had complaints. Remember, you don't stand 5" away from a large print, more like 5' (plus)

I have nothing against full frame, I just don't believe that there is enough extra benifit to spend the $$ for my use.

wingclui44 Loc: CT USA

I would like to address something that I hope that's correct!The DoF won't be different between two cameras with FX and DX sensor, if you shoot the same object with the same lens at the same aperture and at the same distance. The only difference is the size of the object on both final image. The one on the DX sensor will be smaller, but the DOF will be the same.
If you crop the image from the FX to the same size of the DX, they all be the same.
In this case, the distance is the factor, you need to get closer to the object with the FX camera to get the same size of the object as taken with the DX.
Since DoF is affected by three factors: Focal length of the lens; Aperture and Distance. Longer focal lens gives less Dof, closer the camera to the object, less Dof, and of course wider aperture gets less Dof.

GoofyNewfie Loc: Kansas City

With a full frame equivalent focal length lens, at the same aperture and distance you get the same angle of view, but the crop sensor camera will have 1.5 (Nikon), 1.6 (Canon) or 2x(m4/3) more depth of field at the same aperture.

I like being able to isolate a subject using shallow depth of field, so my preference is to use a full-frame camera. If budget allowed, I would really like a medium-format camera. It would allow an even greater separation.

Crwiwy Loc: Devon UK

You will get many differing answers on this one - especially from the 'pixel peepers' - but the main fact is what you do with the camera and what pictures you take.

There have been many competitions won with a cropped sensor pictures against much more expensive 'superior' full frame cameras.

Probably one of the main differences that you will notice is that a lens has an effective greater focal length with a crop sensor. For example - a 270mm lens on a crop sensor (Canon) will give the same magnification as a 420mm lens on a full frame camera.