Check your microadjust - It makes a BIG difference

[etherial]

Hi Etherial,

I also have the 70-200 f/2.8 MK1 and I am interested in doing this 45 degree test. I understand everything that has been said for directions except consistency through all zoom ranges. How do I test consistency for all zoom ranges?

I am interested to see the results!

Thanks,
Taylor

Hi Taylor, you can just do the tests at a few points through the range. I did three points, 70mm, 130mm and 200mm. I found that after my lens came back from canon I got the same result at each focal length. If they are slightly different you can bias your adjustment based on what focal length you use most. Or send you lens away for calibration.

[joele]

I don't know how good the 45 degree test is, as the af point isn't exactly a tiny centred point within the small box within the viewfinder, shooting at a flat target for adjustments is better... try the method below.

http://www.birdphotographers.net/for...ustment-tricks

[AdamJL]

You can do the 45 degree test the same way I did it. Set the test paper up at 45 degrees and then have the camera set up accross the room pointing at it. Just put the test page on something rigid and stand it at 45 degrees on something like a chair. Set you camera up on a tripod, and away you go.

Hi etherial. I hope you realise just how big that slider will have to be!

The centre focus point when you stand far away (and you really should be doing all Micro Adjusts at the distance you'd normally use the lens) with a 500mm lens would nearly cover half an A4 page, possibly more.

[etherial]

I don't know how good the 45 degree test is, as the af point isn't exactly a tiny centred point within the small box within the viewfinder, shooting at a flat target for adjustments is better... try the method below.

http://www.birdphotographers.net/for...ustment-tricks

Yes I read that thread a few times and used that method the first time. I found though that it doesn't give you a reference on which way to adjust. For me the 45 degree method was easier as it gives you instant feedback of how far out and what direction to adjust.

There are a heap of methods out there, it's a matter of finding one that works for you.

Mic

[etherial]

Hi etherial. I hope you realise just how big that slider will have to be!

The centre focus point when you stand far away (and you really should be doing all Micro Adjusts at the distance you'd normally use the lens) with a 500mm lens would nearly cover half an A4 page, possibly more.

Hi Adam, I'm not sure what you mean by "slider". Anyway Canon recommend 50x the focal length as the test distance, so for your 500mm that would be 25m.

[etherial]

For the techo nuts out there...here is another method. I tried this too early on but found I couldn't get repeatable results. As I said before, find a method that suits you.

http://www.northlight-images.co.uk/a...djustment.html

[TassieSnapper]

Im interested in reading your test document, the thing about pet ownership and the like. Can you please post a shot of the whole page?

[etherial]

Im interested in reading your test document, the thing about pet ownership and the like. Can you please post a shot of the whole page?

Serious?

[TassieSnapper]

Serious?

[AdamJL]

Hi Adam, I'm not sure what you mean by "slider". Anyway Canon recommend 50x the focal length as the test distance, so for your 500mm that would be 25m.

Hi etherial

Apologies, by slider I meant the old 45-degree ruler thing that's commonly used. But in any case, whatever is the target, believe me, it's completely impractical to MA a 500mm lens this way. The target has to be very big so the focus doesn't cover it (and at 50m, it has to be huge).

[arthurking83]

I agree with Adam, and recently basically explained the same thing to another member.

The problem with these 45° A4 paper tests is that you are really really really close to the subject, which is not always the case in your real photos.
Getting too close can magnify a problem to the point where if you adjust for back-front focusing issues up close it may work against you at normal operating distances due to the naturally deeper DOF(at the same lens settings).

lenses(like the Nikon 80-200/2.8 in my case) CAN have different focusing characteristics at different focus distances.
Note! I did say CAN. My Tammy 28-75/2.8 is consistent in it's backfocus issue at all focus distances, where the Nikon was OK close up, but backfocused at standard portrait distances(say 5-10meters away!.. damned annoying to say the least).

I don't check using the 45° test.
The battery test is better, or the wall mounted test chart at a reasonable (if you have liveview) as another alternative.

[etherial]

Just to be clear, I don't advocate doing it the way it is pictured in the other thread as it seems way to close. I still kept to Canon's recommended minimum of 50x the focal length so when doing the 200mm I was going through two rooms of the house . (My wife thinks I'm nuts by the way!)