Opinion requested re micro adj required or not

Hi,

could I ask those with experience of microadjusting lenses to take a look at the shot below please and tell me whether you think my lens needs MA. I think it does but, first of all I've never done this before and secondly I've no benchmark to compare it with, hence I'd like opinion please, preferably from those who've done this procedure.
The shot is a JPEG, taken with a 1DmkIV plus 400mm f/5.6 lens. Taken from 20m away (50 x the focal length) 1/400 sec; ISO 200. The camera was tripod mounted and wired remote activated. AF using liveview at max mag was used. 3 shots were taken, all look the same. The only pp was minor sharpening. What you see is a 100% crop.
If you look at the yellow security info on the box, to me that's OOF hence I think the lens needs MA. That's just my opinion of course, would you agree or am I expecting too much?
Thanks for looking.

HTTP response: NOT FOUND | MIME changed to 'image/gif' | Redirected to error image by FLICKR

2slo wrote in post #14604699
AF using liveview at max mag was used.

You were in liveview and used AF. Did you use Live Mode or Quick Mode for the AF (see p.138 of the manual)? The former doesn't use the normal AF system, so MA would have no effect!

hollis_f wrote in post #14604841
You were in liveview and used AF. Did you use Live Mode or Quick Mode for the AF (see p.138 of the manual)? The former doesn't use the normal AF system, so MA would have no effect!

err, p 138 of the 1DIV manual I have covers manual focussing?
I enabled live view stills from the menu, camera in manual mode/jpeg/ settings as above and AFd at full mag then 100% crop of the resulting image. Any help?

EDIT: p136 covers quick mode in my manual. No, I didn't use that, just as detailed above. I used back button AF in conjunction with wired remote.

2slo wrote in post #14604873
err, p 138 of the 1DIV manual I have covers manual focussing?

Whoops! Dunno why I assumed it was a 7D. Silly me!

2slo wrote in post #14604873
EDIT: p136 covers quick mode in my manual. No, I didn't use that, just as detailed above. I used back button AF in conjunction with wired remote.

OK. There are two ways your 1D can focus in liveview (maybe three if it has face-recognition, but we'll ignore that). Live Mode is the default. That takes the data from the sensor and looks at the contrast, then it moves the lens a bit, checks the contrast again, moves the lens, checks, and round and round until there's no improvement in the contrast.

This method is slow, but accurate - because it is using the image produced by the sensor.

The other methos, Quick Mode, uses the AF system that is used most of the time (all of the time when not in liveview). In this mode some of the light is directed to a special AF sensor. This uses a complicated mechanism called Phase Detection which can tell just how far the lens has to move and in which direction to get spot-on focus. So it makes that measurement, tells the lens how far to move, waits for the lens to say 'OK, I'm there' and then tells the camera it's ready to go.

This method is very fast but it does rely on the camera being able to judge how far the lens must move and also on the lens moving the same distance as it's been told to move.

It's impossible to engineer such systems to be 100% accurate, so there is some leeway in how accurate the two systems are. Most of the time there's no real problem, but you can get some cases where a camera that's slightly front-focusing matches with a lens that's slightly front-focusing to get a system that's noticeably front focusing. That's where Micro Focus Adjust can help.

You can check your lenses using the different focusing modes in liveview. Take a couple of images using Live Mode (using contrast detection, which doesn't use the AF sensor) and a couple using Quick Mode (which does use the AF sensor). If the latter are not as sharp as the former then you may have a problem.

Thanks Frank, I will give that a try as soon as I get a chance.
Just based on the image above from the way I did it, do you think that's accepatably sharp for a 100% crop from 20m? Having read a bit on MA, the tethered method of MA using the EOS utility, set up with camera as described above seems worth a try. Easy to reset to default if it doesn't produce an improvement.

No, not acceptable and yes, you need to try MA'ing that lens. I'll give you an easier way to do it though - tape a $1 dollar bill to a flat wall, take camera and lens and setup roughly 20 ft. from the wall. Using LV, focus on the center of the bill. Now using LV again, move the focus point to the lower left corner of the bill where you should see some printed lines in the material. They should be absolutely sharp. If not, time to start adjusting until they are.

This is the method I use and never have to take a picture to do it and it has never let me down.

huntersdad wrote in post #14605159
No, not acceptable and yes, you need to try MA'ing that lens. I'll give you an easier way to do it though - tape a $1 dollar bill to a flat wall, take camera and lens and setup roughly 20 ft. from the wall. Using LV, focus on the center of the bill. Now using LV again, move the focus point to the lower left corner of the bill where you should see some printed lines in the material. They should be absolutely sharp. If not, time to start adjusting until they are.

This is the method I use and never have to take a picture to do it and it has never let me down.

Thanks for the reply and info, what you suggest is pretty much the same basic principle as the tethered method albiet simpler and easier to do.
I would say that 20ft sounds a bit too close for a 400mm lens though, most suggest 25 - 50x the focal length to adjust at distances appropriate to those the lens will be used at.

Just a guess, but did the lens have a filter? From the image it looks more as if there are optical reflections. I have had issues with filters in the past and they sure look like the photo you posted.

You might try doing this with a better subject. It looks like it was shot through glass and there was out of focus stuff in the foreground partially obscuring it. Not a good candidate for focus testing. You need a clean light path.

I done my 85mm & possibly the 50mm in camera!!

I used normal back button focus then flicked to live view, zoomed in & compared it by manually adjusting the focus of the lens. Depending which way brings the live view image into better focus, adjust the MA then try again.

Obviously tripod mounted, all in line etc

for a subject 60+ ft away and a 100% crop it looks good to me.
but I would use teamspeed's focus chart in his sig to check for issues

gjl711 wrote in post #14605330
Just a guess, but did the lens have a filter? From the image it looks more as if there are optical reflections. I have had issues with filters in the past and they sure look like the photo you posted.

Ditto. I got shots that looked like this with my 100-400L until I took the filter off. The lens performs much better without a filter and with a hood than it does the other way around.

Thanks Gents. No filter fitted. I'm currently trying a test chart on a wall at 20m. The results just look blurry whichever way I MA (tried in +/- 5 steps up to +/- 20). I'm going to try it at half the distance and see what smaller changes look like.

2slo wrote in post #14605435
Thanks Gents. No filter fitted. I'm currently trying a test chart on a wall at 20m. The results just look blurry whichever way I MA (tried in +/- 5 steps up to +/- 20). I'm going to try it at half the distance and see what smaller changes look like.

You might want to invest in FoCal, a bit of software that automates the MA process.

You must have been standing over my shoulder this morning Frank, just what I've been looking at
Having said that, doing adjustments at 10m using a test chart, I can see a definite improvement with a MA of +5 (on the camera screen anyway) so I'm setting it on that for now, more test pics to follow, if this is boring let me know and I'll cease immediately