Len,s calibration

[Ben]

Hello folks, For good reasons,I don,t think I am getting the best out of my lenses, so therefore I want to do a Micro adjust ,
Now,??? the different guides say this should be done at Máximum aperture, ie 2.8 f
A 70mm-200mm , the depth of field at the suggested distance of 5x the focal length would be minimal ,
So? how can one assess the fore and aft focus point, Not having tried yet, am I making a mountain out of a mole hill
Or put a 2x converter on and this must be more difficult to ascertain,
Any advice would be most welcome, regards Ben

[the black fox]

Re: Len,s calibration

Trust me Ben it's not as easy as it sounds ,you will at minimum need a proper 45degree slide adjuster ,,they can be either bought of downloaded from the net and printed out and assembled ,also you will need a sturdy tripod and head .cameras need to be in single shot with the lens wide open .and focussed dead on the zero marker and locked down solid ,I find around twenty feet is the right distance for discerning whether any adjustments are needed .done quite a few for friends ,the most recent being Steve Dawes from the forum .your a bit to far away to pop round and help though .

[Ben]

Re: Len,s calibration

Hi Jeff, thanks for your reply, I have decided to obtain the necessary to do it properly , and now I see I missed a 0, zero, off my post,
Your advice for 20 feet seems OK, as I have read for telephoto about that distance to 30 feet is fine,
There are many video and related articles of this and some are very confusing,
It,s a good place to pop around ,and at the moment the weather is about perfect, a balmy 25 cel,
Thanks again, Ben

[the black fox]

Re: Len,s calibration

The worst one I ever did was my old 70d ,as it had a will of its own and wouldn't retain the settings ,totally did my head in for six months ,even thought it was my lens playing up ,took testing the lens with several other cameras to pin down the fault to the camera .sold the Camera and the new 80D is perfect every time .

[Ben]

Re: Len,s calibration

Hi Jeff, I received at great cost??? but worth it a Spydercal, chart and immediately set to in refocusing my 7dmk 2 plus 70mm-200,f2.8 +2x converter, and found it was 10 points(bars), back focus , I had suspected from trial shots of subjects that this was the case , but how much, would have been a guess , and looking at some photo,s (birds) I could not ascertain if it was me or the focus,
Know I know, now all I have to do is check the rest of my gear,
If you want to borrow it, just pop over and use it,
regards Ben

[the black fox]

Re: Len,s calibration

Well done ,it's funny the one I did for Steve Dawes turned out to be the TC as well .

[Ben]

Re: Len,s calibration

Well done ,it's funny the one I did for Steve Dawes turned out to be the TC as well .

Hi, Jeff, after the first attempt, which was quite good, after a sleepiness night and a rethink, I set too calibrate the 70mm/200mm/f2.8 is first, Zero all, determining the correct setting and the Adding the 2x converter and calibrating that, which was only slight, a test shot this morning was EXCELLENT, and am most pleased,
Although in the past I had some fair results, there were a few inconsistency, hopefully it will only be ME in the future,
Now I will continue with the other lens,s
I can recommend anyone who thinks that they may have less than perfect results with there pictures to consider looking at there focus,
regards Ben

[the black fox]

Re: Len,s calibration

As long as it carries over into field work it can only be for the best