Crop vs Fullframe
Tento článek je bohužel dostupný jen v angličtině
I have recently switched from Canon 7D to Canon 5D Mark II (i.e. 1.6x crop to fullframe) and I would like to share my experience, together with some practical tips and issues.
If you are thinking about a similar change, you probably know a lot of technical details, so I won’t bother you with these things.
The 5D2 body is virtually the same size and weight as the 7D, but with the 7D you can use smaller and lighter EF-S lenses. During my transition I acquired some pro-lenses, so the complete 5D2-package is noticeably heavier, but the lenses are much better, so I can accept that.
The viewfinder is clearly larger, but the green numbers around (time, aperture, sensitivity etc.) are smaller and a bit harder to read. The 5D also doesn’t have projected grid-lines into the viewfinder. You may buy optional grid-screen, but in 7D I had a completely different screen with split-prism (from Katz Eye) and I am planning to use a similar screen in 5D2, which means I either won’t have the grid, or will have to pay the extra price for a screen with the grid engraved. (I am sure that the projected grid will be in 5D Mark III though.)
The illuminated focusing points are very easy to see on 5D2 even in bright light, but this is not true on 7D. Probably due to new design of the screen (with projected points and grid), the light is much dimmer and you basically cannot see blinking focus confirmation in sunny environments.
Replacing the focusing screen is hard on 7D, but very simple on 5D2. It can be done on both, but you need much more skill on 7D. If you are wondering why would anyone do that then there are some custom screens which feature split-screen focusing and much better display of large apertures. Look for Katz Eye and other manufacturers. I have replaced my screens on 40D, 7D and 5D2 and doing it on 7D was somewhat hazardous.
There is a different shutter sound, probably only slightly louder on 5D2, but not much.
The button layout is very similar, there are only minor differences. The 7D is more configurable and has better movie/live view switch, but nothing really ground breaking.
Not a 5D2 thing, but a side note: The pro (L-grade) lenses have reversed positions of zoom and focus rings in comparison with the lower grade zooms, which takes some time getting used to. The zoom ring is closer to the body, which is a good idea especially in the case of 70-200/2.8, i.e. a very heavy and long lens, where the palm is resting in the position of the zoom ring and the other ring is inconveniently far for simple use. The AF on 5D2 is O.K. though, so using it is usually unnecessary.
Less noise in high ISO photos is a nice feature to have. The photos from 5D2 are cleaner than from 7D, but not in a revolutionary way, it’s just a step above. The good thing is the availability of ISO 50. If you are using external flashes with the limitation of X-sync speed, you have to either use small aperture and/or stack filters in front of you lens (which will get you pretty dark viewfinder). With such a low ISO, you can avoid some of these complications. Unfortunately, some tests show that there is some reduction in dynamic range :(
Of course, with the same aperture the depth of field is much thinner on 5D2. This was my #1 reason to buy it! However, be aware of the consequences. In order to take the same photograph, you would need different focal length (i.e. 50 mm on Canon crop cameras equals 50 * 1.6 = 80 mm on fullframe) and also smaller aperture: 50 mm / F4.0 on crop is approximately 80 mm / F6.4 on fullframe. Generally, this means difference about 1.35 F-stop, so in another words on 5D2 you need about 2.5-times more light to achieve the same depth of field, meaning you might need either more powerful lights (in studio) or better tripod (outside). Also lenses with Image Stabilization are more useful on fullframe. Alternatively you can, of course, increase the ISO, but this will probably get you on about the same level with noise as on 7D. In such a situation, there is no gain, but fortunately also no loss.
The colors seems to be a bit more saturated on 5D2 using the same lens, but the same effect can be achieved with 7D by adding +5 points to saturation slider in Lightroom. Not sure if it will make any real difference.
I have to say that user interface and image processing of both cameras feel fast enough for me.
I feared that the autofocus in 5D2 is obsolete, but so far in studio and exterior work it seems fine and the center focusing point is about as good as on 7D in terms of both speed and ability to focus in darkness. The outer focus points are not that good on 5D2. The 7D is able to focus with the farthest point as well as with its center point, while similar point on 5D2 looses its abilities in dark. I wasn’t able to test quickly moving vehicles, but generally I don’t do such photography anyway, so I don’t miss the advanced focusing features on 7D. The 7D with the plethora of points is also hard/awkward to use – on 5D2 (and also previously on my 40D) with 9 focusing points, you have a custom function to turn the mini-joystick to the focus point selector. One click to the each direction selects the desired point… easy and very fast way, which can be done blind-folded or in moments, when you do not have the camera near your eyes. On 7D one needs so many clicks to select the single point, that I usually ended up using the center point only.
On 5D2 there is a longer mirror blackout (the time when the camera is actually taking the picture, the mirror is up and the photographer sees black viewfinder; 7D: 100 ms; 5D2: 145 ms) and a lower frame rate (7D: 8 fps; 5D2: 3.9 fps). I don’t shoot sports, so the frame rate is not a crucial factor, but it can be also useful when shooting multiple consecutive frames with different exposure for later merging or HDR experiments.
Also, the 7D has X-sync speed of 1/250 s and in my strobist experiments it can pretty reliably sync any flash from 1/200 s and most of them even of full 1/250 s. The 5D2 has X-sync speed of 1/200 s and is reliable only to 1/160 s with external strobes/flashes. When using 1/200 s you might see a dark edge in you picture. This speed limitation might pose a problem is bright environments, meaning you will need more powerful strobes to overpower the ambient light.
I am happy to have the 5D Mark II, although the 7D is also very very fine camera. Both have their strong points: 5D2 can achieve smaller depth of field and have better low-light capabilities; 7D contains much more advanced AF module and can use smaller lenses, meaning it is easier to travel with.
Both cameras can take stunning pictures, but it is crucial to remember that it is only a tool and not a decisive factor when taking pictures. Much more important are the light, environment, models and the ideas. Camera can only help you enhance these things or make your shooting easier. Enjoy it!