Canon EOS 5D

Introduction

After two years and two months of using Canon EOS 20D I decided to go full frame. I kind of have been waiting full frame camera with sensor with dust cleaning system, but since it seems Canon isn't updating (on spring 2007 Canon released Canon EOS 1D mk III but no replacement to 5D neither Canon 1Ds Mk II). Canon may hold the updating since it has market covered - no-one else won't deliver full frame cameras (2007/July).

I did leave Canon EOS 20D to my backup camera. However I don't know much I have usage for it. On some rare times I would like to have two camera bodies to avoid lens changes.

Ergonomics

After 20D the moving to 5D was not a big deal. All the functions were more or less the same. Camera feels very good on hand.

There are few thing I don't like in the camera on usage point of view:
- the mirror lock-up function still has to be activated from the custom functions. You can program this to customer settings in the dial where you have M, Av, Tv etc. - I did this, now when I turn the knob to "C" I get mirror lock-up, timer and "M"-mode and if I need to photograph something else I just switch to Av. However why the hell Canon has added button for direct printing but there is no mirror lock-up button (it would be nice to be able to switch print button's function to mirror lock-up via custom function)

Viewfinder & Manual Focusing

The viewfinder is bigger and brighter than in 20D. I don't know is this the reason but I have found out that with 5D I can keep my other eye open while with other eye I focus and compose. For reason or another I could not do that with 20D.

Typically I take my photos so that the main target is not in the center of the screen, more likely close to 1/3 from corners of the picture. Also I typically use quite shallow depth of field.

However Canon has put the focus points to diamond shape in middle of the viewfinder (see picture on right - click picture for larger version). Also the the outer focus points are not cross-type neither they are very accurate. Also when using shallow depth of field it's not good idea to focus&recompose, so using center focus point is out of the question on most of the cases. Due to reasons above I can't use autofocus very often and therefore I manually focus my photos quite often.

Viewfinder screen Ee-A

This is the standard viewfinder screen which comes with the camera. The viewfinder is very bright and if you don't have to manual focus I think it's excellent. However the standard viewfinder screen is a joke for manual focusing. Luckily Canon made the focusing screen changeable by user like in 1D series and manual focusing problems can be avoided easily by changing lens.

Viewfinder screen Ee-S

Canon is making also making special focus screen for manual focusing lenses which aperture is faster than f/2.8. It has "steeper parabola" and should make image to pop into focus. However I didn't find it so great. Of course it's better than the original focusing screen, but I didn't found the image to "pop" into focus. Actually I had to check my old Pentax ME and Pentax 50/1.7 and to my supprice I found that 1) Pentax viewfinder image is bigger 2) Pentax viewfinder image is brigter 3) Pentax is easier to manual focus (if image is in focus or out of focus it appear better from Pentax viewfinder).

I asked this from the gurus on Fred Miranda forum and the explanation was that on autofocus camera lose 40% of the light due to half-silvered mirror, since the autofocus sensors behind the mirror need the light as well. On manual focus cameras the mirror is 100% reflective and due to that there is so much more light that the focusing screen were made much coarser and this is the reason why manual focus cameras are so much better on manual focusing.

With slower lenses (e.g. Canon EF 17-40 f/4 L USM the viewfinder get pretty dark and goes worse when using polarizer. I'm comfortable focusing manually f/2 and faster lenses with polarizer, but f/2.8 lenses get too dark to focus with polarizer. Luckily I don't have many that slow lenses, and for example Contax Distagon T* 28mm f/2.8 I will anyhow focus on most typical situation using hyperfocal method.

I later may consider alternative option for focusing screen (e.g. Brightscreen), but at the moment have to survive what I have. Also before going to alternative screens I will try the Bill Maxwell Hi-Lux threatment (unofficial homepage: link).

Image Quality: ISO performance

In addition to lower noise on higher ISOs 5D also offers more exact way of setting the ISO speeds. They can be set 1/3 stop steps, when in 20D they had to be set by 1 stop steps.

Image Quality: Colors & Contrast

For reason or another I have found out that 5D photos seem to require less digital darkroom work than images from 20D. I don't know is this due to less strong antialias filter or what, but this happens with same lenses. For some part this is definitely caused because with full frame sensor the image doesn't have to be magnified as much as with 1.6x crop.

Image Quality: Lens performance

Bigger sensor has positive and negative effects. Positive effect is of course that the image doesn't have to be enlarged so much and even lesser quality lenses appear better due to that. Negative effects are caused because camera is no longer using just the "sweet spot" of the lens in middle, instead sensor also get picture from the outer zones of image circle lens is projecting. Typically this is more problem with wider lenses. Long tele lenses have so big image circle that there usually are problems.

Personally I'm not so worried about the drawbacks since I have tried to get best quality lenses for focal lengths which I'm using. And I also don't use zoom lenses, which typically are lesser quality than primes.

Less enlargement required

To get same size print less enlargement is required than from cropped camera. In practice this that lens doesn't have to deliver as many lines/mm as it does in cropped camera to get same end result.

Corner performance

Vignetting

At full aperture most of the lens have some vignetting. This usually goes away when you close the aperture couple stops. With the zoom lenses and lower quality primes this is bigger problem.

There have been also discussion about vignetting caused by extension tubes - I have not yet found this as a problem but I will report here if I see this phenomenon.

Distortion

I found out my Canon EF 17-40 f/4 L USM to have much worse distortion at full frame than it does have on 1.6x crop

Dust?

Add chapter here when sensor needs to be cleaned first time.

Conclusion

Pros

• Full Frame: Smaller magnification (less pixels/mm needed for same size picture)
• Full Frame: Bigger pixels than 12Mpix cropped camera has ==> less noise and diffraction problems
• Full Frame: Better control of depth of field
• Good performance at higher ISO values
• Less need for digital darkroom work

Cons

• Fulll Frame: Corner Performance
• Fulll Frame: Vignetting
• Fulll Frame: Distortion
• Viewfinder & viewfinder screens for manual focusing are not as good as in real manual focus cameras, however positioning of autofocus sensors forces to use manual focus most of the time