Best DIY focus trim method

[Dan Santoso]

Hallo All,

I need to calibrate my XF/3100 focus trim and there are many method in the internet.

Have anyone try the moire method describe here:
AF microadjustment for the 1Ds mark III, 1D Mk3, 5D Mk2, 7D, 1D X
autofocus - What is the best way to micro-adjust a camera body to a particular lens? - Photography Stack Exchange

I have tried a long time ago with dslr and I am not sure about with the XF.

Also in the web, many free pattern is available. Some method the pattern lay down in floor while the camera 45 degree down ( I have tried this and it was hard to make sure the pattern is square to the camera. left and right part of the pattern has slightly different focus point. Other has the pattern in 45 degree flat surface while the camera is straight on (lens align method).

Can someone please give some advise regarding best DIY focus trim?

Thanks,
Dan

 

[DrakeJ]

It's not a DIY tips per se, but I've had perfect results with the simple spyder lenscal.

 

[mjr]

I have a very good DIY system for focus trim, it's a 1m long piece of wood with around 10 2" screws sticking half way out down the length, one in the middle I popped some white paint on. Lean it at 45 degrees around 3m from the camera as I am generally shooting portraits with af and this is a reasonable working distance, then tether, tripod, af on the white screw and adjust from there so it hits it spot on. Costs nothing to make and works well although I'm sure there are far more professional ways of doing it!

Mat

 

[Bill Caulfeild-Browne]

I do it quite differently. I autofocus on an object at infinity at full aperture. I then take a shot, followed by one at +100 focus trim and another at -100 focus trim. I review these at 100% on my computer screen (not the back) and choose whether the "+"or the "-" is sharper.

Then, if the "+" is sharper I take a whole series at +25 point intervals, probably about 10 shots, so I have a range from zero trim to +250 trim. I choose the sharpest and then do a couple more shots at 10 points on either side. That's enough - I find the difference between, say, +150 and +155 impossible to discern. (After all, most MF lenses are f2.8 or 3.5 max aperture which gives some DOF, however shallow.)

I choose this method because most of my shooting is at least at 5 metres to infinity and I don't see any point in calibrating at close distances that I use infrequently.

In fact all my lenses need negative trim, generally around -150 points. The fact that they are all very close implies the trim is simply compensating for mirror and/or back alignment. I have recently been shooting bears, beavers and birds, all at full aperture and focus is right on in every case.

 

[MGrayson]

My method Focus is spot on (look at the tape measure).

Actually, like Bill, I focus on a building 1/2 mile away. Color Moiré on the vertical lines is a good sign. This is at 200%.

--Matt

Note - my camera doesn't have focus trim, so this is just a check. AF at infinity is not perfect on the Leica S, so I like to know exactly which part of the infinity sign is where infinity actually is. At portrait distances, it's perfect.

 

[Bill Caulfeild-Browne]

I presume you check focus before sampling the bottle?

 

[aztwang]

I have tried most the methods above and in real life ( I shoot portraiture) my results are not exactly accurate when I go live.......So instead I set my trim using a yard stick, 45 degrees at about 10 ft working distance, this gives me a starting point. Then I tether up in the studio and set up a test portrait session, shoot @ f5.6 with staggered eyes and my digital tech checks the eyes and we adjust accordingly. Once we nail it we double check wide open..Thats it. I find adjusting trim based on real working distances is much more imparitive with MFD than 35DSLR. I may be full of malarkey but it works for me...LOL

Cheers

Don

 

[MGrayson]

I presume you check focus before sampling the bottle?

Indeed, Bill. A drinking game where you take a shot whenever focus is off would not end well.

Don,

My wife was in a road race and I was at the finish line with an unfamiliar lens (Minolta 200/2.8 on Sony A7II). Fortunately, she was 20 minutes slower than the early finishers, so I had plenty of time to fine-tune the AF in practice (as opposed to test targets) before she came in view. You are absolutely right that getting AF right in use is the ONLY thing that matters. Fortunately for landscape shooters, stationary targets usually suffice.

Best,

Matt

 

[Dan Santoso]

In the end i just download pattern and it seems to work with the 45° angle. All of my lenses sit on +50 now.

Thanks all

 

[algrove]

Interesting thread and philosophies.

I have an XF which I have primarily to use for landscape. However, I trimmed all my lenses using LensAlign. Perhaps that was wrong. Sadly I am just back from a 3 week trip and if I I have any focus problems I must look to changing trimming from LensAlign to something different. That said I did not shoot any lenses wide open due to uncertainties in sharpness. I anticipate to print most of my selects up to 24x36 or 24x48.

 

[Wayne Fox]

when my new back showed up a few days ago I set the trim on all of my lenses using lens align. Last night I was out in the back yard experimenting with the focus stack feature, trying to figure out how to use AF reliably with that tool, and I noticed infinity was not sharp. I decided to reset the trim based on infinity, and found that even items closer focused just fine, but now infinity was also sharp. I'm going to test it on other glass this evening, but I think I'll probably stick with using infinity to set trim.

As an aside, interestingly enough using the focus trim (edit: I meant focus stack) tool and live view, infinity would be sharp at 80, and focus trim was sharp at -80. I don't know if that is a coincidence or if the focus trim number actually corresponds to the opposite of actual motor turn number in the focus stack tool for what the camera determines should have infinity sharp. I'll see how my other lenses turn out.

 

[algrove]

when my new back showed up a few days ago I set the trim on all of my lenses using lens align. Last night I was out in the back yard experimenting with the focus stack feature, trying to figure out how to use AF reliably with that tool, and I noticed infinity was not sharp. I decided to reset the trim based on infinity, and found that even items closer focused just fine, but now infinity was also sharp. I'm going to test it on other glass this evening, but I think I'll probably stick with using infinity to set trim.

As an aside, interestingly enough using the focus trim tool and live view, infinity would be sharp at 80, and focus trim was sharp at -80. I don't know if that is a coincidence or if the focus trim number actually corresponds to the opposite of actual motor turn number in the focus stack tool for what the camera determines should have infinity sharp. I'll see how my other lenses turn out.

Wayne
In the first paragraph you said you set ytim on ALL lenses using Lensalign. Then in the second paragraph you talked about focus trim and in the last sentence you said you will see how your other lenses turn out using the new trim method. What lens did you use in the last focus trim example you discuss? TIA.

 

[Wayne Fox]

Wayne
In the first paragraph you said you set ytim on ALL lenses using Lensalign. Then in the second paragraph you talked about focus trim and in the last sentence you said you will see how your other lenses turn out using the new trim method. What lens did you use in the last focus trim example you discuss? TIA.

I edited my post. A little confusing. The lens I was working with was the 40-80. If I focused with liveview in the focus stack tool infinity dialed in at 80. Setting trim using infinity ended up at - 80. Going to test to see if there is a relationship or if both being 80 was a coincidence.

 

[sc_john]

Question on setting focus trim...

Does the XF automatically remember focus trim setting for each lens. For example, if my 55 LS has a focus trim setting of +55 while my 80 80 LS has a focus trim of +100, will those settings be used by XF when I mount respective lens. Or, will I have to manually enter the focus trim when mounting each lens.

Thanks.

John

 

[mjr]

It remembers John, the new blue ring lenses contain a chip so that the body will remember per specific lens but for non blue ring it remembers for the focal length, only an issue if you have more than one of the same focal length that needs different trim, unlikely but possible I suppose.

Mat

 

[sc_john]

It remembers John...

Mat

Thanks, Mat! That's what I was hoping for.

John

 

[Bill Caulfeild-Browne]

I have LensAlign but to be quite honest I don't find it easy to use, nor consistent. I first used it for all my lenses and the results at infinity were unacceptable. Using my method described above, infinity is perfect - and so are close-ups. I don't understand why this should be - but I have a LensAlign kit I'll happily sell!

 

[Wayne Fox]

I have LensAlign but to be quite honest I don't find it easy to use, nor consistent. I first used it for all my lenses and the results at infinity were unacceptable.

I had the same results. LensAlign seems to work fine for Canons and Nikons, but for some reason with the XF infinity was horrible if I set focus trim with LensAlign. All my lens are now set at infinity.

And I also found the relationship between infinity in the focus stack tool and infinity in the focus trim setting doesn't necessarily correlate. Just a coincidence with my 40-80.

My method was pretty simple, manual focus using Live View at infinity, carefully note where the infinity mark aligned on the lens. Set trim and perform AF, if the lens wasn't in the same spot adjust the trim and repeat until the lens appear in the same location. Then fine tune with either live view or taking shots. Went pretty quickly.