[wim]

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Pretend I know nothing about cameras.  Is it really that easy to change focus screens on the 6D, and the secret is to stick with Canon made screens?  That is VERY valuable information, and all of us Canon shooters are adding to our knowledge whether we thank BC or not!  My question:  Does this apply to the Canon 5D Mark II? 

 

I listen to you guy's arguments that demonstrated the superiority of the 6D over the 5D Mark II, but I was given a pristine 5D Mark II, and a 1.4x teleconverter, my Christmas gifts!  So, needless to say, I've gladly accepted it, and will finally experience the world of FF shooting!  I will attempt to look this up on the internet.  I just received the camera yesterday evening.  But, how great it would be if I could switch to the fast screen, with out having to be a camera tech. 

 

@ Wim, and Klaus (who made a reference in a different thread).  You have made comments that are thought provoking.  Being not at the level to really need to know how it's done, but still curious about MFA.  Wim, you mention that the lens is shimmed at the factory if necessary to adjust any back/front focusing inherent in the lens (paraphrasing of course). 

 

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Hi Arthur,

 

Just quoted the relevant parts.

 

Yes, replacing focusing screens with Canon alternatives is an option indeed.  I have the laser precision matte, which I ordered straight away with the order for my camera almost 7 years ago (5D II). I wanted it speciically for manually focusing my faster primes, plus my TS-Es and MP-E. I also had it on my 5D (mk I), and on the 1D Mk III .

 

Superiority of 6D is relative. It has slightly lower noise levels, but personally, I rarely shoot over 1600 iso, so it has never been a problem for me. The 6D is better in some ways, the 5D II in others. To really get a better camera in all aspects, you'd need to go to 5D III and up. However, 6D and 5D II are fine cameras with glorious image files regardless.

 

If this is your first FF camera, you may be totally surprised . In a positive way that is .

 

As to shims: what really happens is that camera mounts are shimmed, and focusing screens, or focusing screen holder systems, in such cases, are shimmed so that they concur with the standards set by the camera maker for accurate positioning of lenses and accurate focusing. They can be shimmed for exact distances and angles (the latter by using shims which are thinner on one end, and thicker at the other, in a gradual transition).

 

Lenses also are shimmed, again to make sure they are positioned correctly, for correct distance to manufacturer standard to the sensor, and for correct focusing distances.

 

These standards always have some leeway or standard deviation, and that may result in still not correctly focusing lenses (if the deviation is, f.e., both ways the same, the total may end up as being just too much for correct focus, or not at the sharpest point of focus). This is why there is MFA on many of the newer cameras, often on a per lens basis.

 

In addition, lenses are often also electronically adjustable,, which is generally something done at a service point, or even at the factory. This may be necessary of , f.e., a lens shows focus shift when changing from the widest aperture to a smaller one, like Canon did with my 50L and 85L II.

 

HTH, kind regards, Wim