Are full frame DSLRs still much better in 2012 in terms of image quality?I've seen some comparison images that look about the same and some where the 5D2 seems very slightly better. Snapshot says the 5D2 is 20% better in IQ... is that for real?
It depends upon how you define "much better" and what your priorities are with respect to "image quality", which in turn probably depends upon your intended output more than anything else. Morro Bay harbor Pigeon Point Lighthouse
Unless you are printing large - really large - you won't see very much difference in "fine detail, resolution and sharpness". If all you ever print is 5x7s, 8x10s, 11x14s, 13x19s or your most common use of your images is posting them online, you will hardly see any difference at all. Once you get to 16x20 to around 18x24 prints it will be easier to optimize images coming from a FF camera. By the time you get to 20x30 prints and larger, the FF camera will start to pull ahead more clearly.
I've used the following two images several times here on POTN to illustrate this... Which was taken with 5DII and which was take with 50D? Can you tell?
These two images were shot with the same lens (Canon EF 20mm f2.8) and even the same filter on the lens (B+W Kaesemann C-Pol). I know it's hard to tell at Internet resolutions even tho I've provided some tighter details from each image.... You'll just have to take my word for it that it's almost equally hard to tell which camera was used for which when both are printed 16x20" on smooth matte paper with a high quality printer. And, this is comparing 21MP 5DII and 15MP 50D! (The 18MP cameras' images might
be a little easier to detect, depending upon post processing.... they use a stronger AA filter, so require more sharpening... and they tend to be a bit more saturated. Post processing can wipe out a lot of the differences, though.)
The 5D2 seems to have about 1 stop of lower noise. However, assuming I want to maintain the same DoF, I'd need to use an aperture 1 stop smaller and bump the ISO up. That seems to negate some of the low noise advantage. (I know I could also lower the shutter speed, but that's usually not an option in the low light venues I shoot) The 5D3 is maybe 2 stops better. Is that worth $3500?
We all have different opinions about noise and what's usable for each of our purposes, so noise handling by different models is somewhat subjective. I feel my 7Ds are usable to about ISO 3200. They use essentially the same sensor as your T3i, so you are seeing about the same high ISO performance as me. 5DII I use to ISO 6400 without much concern. Like most people, I don't have 5DIII to compare, have only been able to download and check out some sample images from the camera so far... That leads me to believe that the new sensor/processor might make usable ISO 25600 images... But I'm not banking on this until I get a chance to test the camera myself and see how it works within my workflow. Most of the samples I've seen have been JPEGs, so I have to assume were either converted in-camera or might have been converted in post with Canon DPP that's probably better "tuned" for the new model than third party softwares I use. The s'ware I use will probably be updated, too, over the next few months, as it's tweaked to better handle new models. And there will undoubtedly be "profiles" for new camera models, created by users, that will be helpful either used directly or as a guide to create my own profiles. I will not be upsetting my workflow by adopting a new camera early... But I will give it serious consideration in the future.
My crop sensor seems to provide slightly more detail at tele lengths.
Most people feel this way... that the crop cameras "put more pixels on target" and offer a slight advantage with longer lenses. While the 18MP APS-C cameras have a crop factor of 1.6X, their sensors are 2.2X as dense with pixel sites per millimeter, compared to the 5DII. There's relatively little change in resolution with the 5DIII (and an actual drop in resolution with the 1DX, compared to 5DII and 1DsIII).
FF can shoot wider at the same focal lengths, but there are UWA lenses for APS-C like my 10-20mm so I don't see that as a big advantage anymore.
Yes, FF do "leave wide lenses wide"... But crop sensor cameras have the "free telephoto effect" with longer lenses. These are way overly simplistic statements, but hold some truth out in the field. What you can bank on... in order to compose images the same way from the same working distances, your lens kit for FF will generally tend to be bigger, heavier and more expensive. At the wide end, the lens needs to offer up a larger image circle, so might need to be a little bigger and heavier for FF. The biggest difference is at the telephoto end... In order to equal my 300/4 IS on crop camera, which I typically use handheld, for use on FF camera I need to break out the 500/4 IS and a tripod to support it... a whole lot bigger, heavier and more expensive!
With a crop camera, I'm using the best part of the lens. On FF, the edges will suffer from light falloff, CA, softness, etc.
This is true... so long are you are using FF-capable lenses on crop cameras. But if using crop lenses, it's not. I think you'll see what I mean mostly at the wide angle end of the range of focal lengths (most crop-specific lenses are concentrated around the wider end anyway). A 12mm lens is harder to correct than a 20mm lens. The crop lens has to be wider to offer the same angle of view on crop, so it naturally has more inherent wide angle distortion effects. And it will be harder to eliminate CA, softening, etc. from the wider lens.
On the other hand, a crop camera can use all the lenses Canon offers... while a FF camera can only use the EF lenses.
Snapsort reports that a 5D2 has 0.4 stops better dynamic range. Improved DR would be great, but 0.4 stops seems like a pretty small difference. It's only listed as 0.2 stops better than the 7D.
I do believe it's true, that the FF camera offers slightly more dynamic range. You see it in slightly more detail retained in both shadow and highlight areas. It's not a whole lot though, a relatively subtle difference.
Some say that FF has better color depth. I haven't seen any truer colors in comparison shots. Is this a big deal? Does anyone have examples?
I don't know that color depth is any greater. I think the 18MP cameras have more inherent color saturation, but that's pretty easily equalized in post production.
The 21MP FF camera does seem to offer slightly smoother gradations. This can make for a little nicer bokeh out of the same lens.
Another response cites "more depth of field" with FF... which isn't true. In fact, DOF is a factor of lens aperture vs distance to the subject and is not effected by the sensor format at all. What is different is that using the same lens on both, you'll need to move closer to get the same framng with the FF camera, so DOF will appear to be shallower.
Also, because it's sensor is so much less crowded, on a FF camera the lens aperture can be stopped down farther before diffraction starts to take effect. It varies by output size, but the Diffraction Limited Aperture for an 8x10 print out of an 18MP crop Canon is f7.1, while for the 21MP 5DII it's f10. If using the FF camera in order to be able to make larger prints, you offset this gain. (The DLAs cited are the f-stops where diffraction first appears.... It's generally possible to use somwhat smaller apertures before it starts to become very noticeable. For example, I use f8 without any concern on my 7Ds, and don't worry very much about f11, but think twice about using f16 or smaller. On 5DII I'll use f8 and f16 without much concern.... at f22 I'd be a little more worried.)
What is the difference between a pentamirror and pentaprism? I find it very hard to manually focus my T3i. It's near impossible using the viewfinder and it's slow and inaccurate with live view. I'm thinking a larger/better viewfinder would help, right?
In general a pentaprism offers a bigger, brighter viewfinder than a pentamirror. It's not a huge difference, but you can see it if you compare the cameras side by side. You should go to a store that has the different models and see for yourself. Keep in mind that the 7D and the 5DIII (plus the 1DX and probably other future Canon models) have what Canon calls the "Intelligent Viewfinder".... a transmissive LCD that allows the camera to vary the AF point display according to the mode in use and to offer "grid on demand" in the viewfinder. This slightly dims the viewfinder, probalby offsetting any gain from using a true pentaprism. (And when the camera is turned off or in sleep mode, makes the viewfinder even darker. Be sure to power up any cameras you compare, that use this type of focusing screen.)
A downside to the "Intelligent Viewfinder" is that it makes it less practical to install and use specialized focus screens. For example, you can quite easily fit an "S" type Canon screen to 5DII, 50D, 60D and some other models to help with manual focus. There are also third party screens. These cameras are designed for the screen to be easily user interchangeable... simply unclip the frame holding the screen, use a pair of plastic tweezers to remove the old screen and put in the new one, then clip the frame closed.
The cameras with the active matrix viewfinders are not designed for easily changed focus screens. Canon doesn't offer any at all. There are some third party screens available (katzeyeoptics.com and others). But they are considerably more expensive than the Canon screens and a bit more involved to install. Not all users feel comfortable making the swap themselves, working in there around the very delicate mirror and such. Also, the third party screens tend to make Spot Metering inaccurate, on models that have that feature.
A true pentaprism also makes for a slightly larger and heavier camera. Most models have 96% to 98% coverage, however 7D and new 5DIII both have 100% viewfinders, which adds even a bit more size and/or weight.
Is it a bad idea to buy a 7D now since it might be replaced soon? What option would you choose or would you recommend something else?
Who knows if and when Canon will replace the 7D, or what the replacement will offer. Anyone who knows anything will have signed a binding non-disclosure agreement and won't be talking. The rest of us are just guessing and speculating. All in all, it's sort of silly anyway. If the 7D does what you need a camera to do... It will still do that even after a 7D Mark II or whatever is offered. All DSLRs depreciate pretty radically anyway.
One major reason in the past to use 7D (or 60D or 50D, etc.) alongside a 5DII was the FF camera's somewhat lower specification AF system. The FF camera struggles a bit with moving subjects, though it's just fine for most stationary subjects... can be used with sports/action, but will have more misses than the crop cameras. With the new 5DIII, the game changes. The new camera appears to have a much improved AF system that should expand its capabilities nicely. We'll have to wait and see for certain, but the 5DIII's AF improvements appear very promising. There still are some reasons (see above) though, to continue using crop cameras for sports/action.
Because they all use essentially the same sensor and deliver very similar image quality, it's a bit harder to choose among the four 18MP cameras Canon currently offers: T2i/550D, T3i/600D, 60D and 7D. Compared to your present camera.... You'd be giving up the articulated LCD, unless you go with a 60D. If you do a lot of manual focusing, that might be quite useful with Live View.
Your present camera uses more plastic in it's construction, has a 9-point AF system with one cross type point at the center, has a 75,000 click rated shutter, offers up to 1/4000 shutter speed and 1/200 flash sync. To keep them compact, the Rebel/xxxD series use a lot of dual purpose controls and use the single LCD monitor on the rear for all purposes. All the larger xxD and xD models tend to have more direct controls, that many users find faster to use or easier to use while keeping one's eye to the viewfinder, and have a secondary LCD on top showing most camera settings. Some prefer the larger cameras, others prefer the smaller ones. Your camera uses LP-E8 batteries, I believe, which as smaller than and provide a bit fewer shots per charge than the LP-E6 batteries used in all the models listed below (except 50D, which uses BP511A).
They 60D uses plastics too (plastics are not necessarily "bad"... used right they might be as durable or more durable than metal, in some appliactions), but over a metal chassis, has a 9-point AF system with all cross type, has a 100,000 click rated shutter, offers 1/8000 shutter and 1/250 sync. 60D also has sort of a hybrid control layout. 60D shares SD memory cards with your T3i. All the following models use CF memory cards.
The 7D is magnesium clad body over a metal chassis, has a 19-point AF system, all cross type. It also has a discrete processor handling AF functions, and two other processors used for image handling... similar to 1D series cameras. Primarily I find this makes for better tracking of moving subjects (though the 50D and 60D are both pretty good at AI Servo shooting too, better than T3i or 5DII). It's got a 150,000 click rated shutter, 1/8000 and 1/250 same as 60D. It expands upon the traditional xxD camera control layout, with many assignable or customizable. A key additional feature many people note is Micro Adjust, which the 60D doesn't have (but the 50D does).
The 5DII is similar built to 7D (and 50D) but without a built in flash (besides not having an anemic flash in the worst possible place for redeye and ugly shadows, this also means no built-in wireless flash control or focus assist,). It's got a 9-point AF system (actually has 6 add'l "hidden" points for center point expansion, only work in AI Servo though). Only the center point on 5DII is cross type. It's got a 150K click rated shutter, up to 1/8000, but scaled back to a 1/200 flash sync.
5DIII is largely on paper right now... But appears similar build to 5DII, also lacks a built-in flash, has same 150K shutter durability rating, 1/8000, and 1/200 sync. The new 61-point AF system (as many as 41 of them cross type) sounds pretty amazing and makes it a whole new camera in many respects. The 6 frames per second shooting is impressive too, for a full frame camera with a single processor. Canon claims the 5DIII's Digic 5+ processor is 17x faster than the Digic 4 that's in 5DII, 60D, 7D (two of em), and your T3i. They claimed the Digic 4 was 6x faster than the Digic 3 it replaced (which was used in 40D, 5D Classic, among others). Dual memory slots might be handy.... one CF and the other SD type. 5DIII follows the 7D's lead with control layout and "intelligent viewfinder", plus appears to have some new tricks of its own (I love the secondary "joystick" on the vertical grip... and the locking mode dial. But am reserving judgment on the "rate" button and other new things).
Have fun deciding... and shopping!