1D4 and microadjustments

[Jay Gould]

Well, deposit paid and camera waiting for me in Oz!

Just reading through the 1D4 thread at NatureScapes which is mainly concerned - really really concerned - with microadjustments: http://www.naturescapes.net/phpBB3/v...?f=57&t=170702

Are those of you luckily using the 1D4 have front/back focusing issues as described?

If I wasn't a member here and reading about all of the happy 1D4 users, and I read the NS thread I am not sure I would buy the 1D4 until more time has lapsed.

Are many of you using the Lens Align or are you using an image that the upright and parallel to the focal plane as described by Chuck:

"Chuck Westfall, Canon Technical Services Advisor, does not recommend using targets that are angled to the sensor plane. He states in his writings, that angled targets will produce inaccurate results.

Do not attempt to autofocus on an angled chart, because doing so will degrade the consistency of the camera's focusing measurement. Keep in mind that the camera's AF sensor is comprised of multiple pairs of linear pixel arrays. If you attempt to autofocus on a single line in an angled focusing chart, only a few pixels from each active pixel array will "see" the target. Ideally, the contrast in the reference target should cover the entire area of the camera's center focusing point, and the reference target should be perfectly parallel to the camera's focal plane. - Chuck Westfall, December, 2008 The Digital Journalist"

I have just read this for the first time; it is going to cause me to put a post on the LensAlign forum to get some feedback.

I disposed of at least 80% of the images I shot in South America - I am wondering how many discards is due to a front or back focus issue with either my 7D or 5D2. Both cameras and all lenses will be put through microadjusting when I return to Oz in May.

Thanks in advance for your thoughts!

[Cliff Beittel]

. . . Are many of you using the Lens Align or are you using an image that the upright and parallel to the focal plane as described by Chuck [Westfall] . . .

Jay,

Note that the target on the LensAlign is upright and parallel to the focal plane; it is the ruler that isn't. While the upright target allows consistent focus, the slanted ruler allows you to see (though not as easily as you would think) the area of focus. In effect, you are seeing the DOF. The system works. I finally got around to running some thorough tests on my 1Ds mark III and 600f4L IS the other day at 24 feet (I was doing a short-range test because I wanted to photograph small songbirds from my enclosed porch during our two recent East Coast blizzards). I used the long ruler, which is far superior to the original (short) one. The LensAlign showed the 600 with a 25mm ext. tube was dead-on with no microadjustment. The 600 with a 25mm tube and a 1.4x teleconverter, on the other hand, needed a MA of +20 to be even approximately right. Now I know why the 1.4x was giving such dreadful results in past sessions without any MA.

[Doug Brown]

I've never had to perform a microadjustment on any lens-body combination. I have owned the 50D, 7D, Mark III, and Mark IV and have never had a problem with any of my lenses (knock on wood).

[Axel Hildebrandt]

I've never had to perform a microadjustment on any lens-body combination. I have owned the 50D, 7D, Mark III, and Mark IV and have never had a problem with any of my lenses (knock on wood).

Lucky you! I haven't found the need on the Mark IV, either (so far). On the Mark III, the 500 alone was spot on, with 1.4x TC attached, I had to go to +4. I have no clue why the same lens/TC combo does not require MA on the Mark IV.

[Rich Steel]

I use a lens align and find it to be good. My Mk 3 had a +11 adjustment with the 500mm. The MkIV has an adjustment of +7 both with and without the 1.4TC. The 7D runs in at +4. I have found MA does seem to make a difference and all cameras produce very sharp images with these adjustments.

Cheers

Rich

[LouBuonomo]

Jay,

What the rest of the guys said. I am one of the people that has been having trouble with the MK4 FFimg. It is back at Canon for them to diagnose some more. I used the lensAlign afte seeing awful results in the field with my 300 and 500...

I am encourage that many people are happy with this body and that canon can solve the issue. If not I will ask my dealer to replace it.. if that one is off I am going to give up and draw an escape plan.

[Peter Hawrylyshyn]

Jay-
Buried in the Canon WHite Paper on the Mk3 is an explanation of what the the AF micro-calibration scale actually means. "Each focus shift amount is calculated by multiplying the maximum apeture single-sided DOF by 1/8". For a 500mm f4 lens at 40', the single sided DOF is about 2" - so a correction of +10 would only move the focus plane about 2.5". For stationary birds with cameras mounted on a tripod, i can see this would perhaps make a slight difference, but for most BIF or other hand held situations - i suspect operator experience , camera settings and AF techniques may be more important factors contributing to soft images.

The LensAlign system will work very well, but it's very expensive for what it really is. One can easily create a comparable setup at home using downloadable test charts (Artie had one in his Mk 3 User Guide). Having learnt the hard way, it is important that the test pattern for focussing be upright and parallel to the focal plane of the camera, as Cliff pointed out.

There's also a lot of debate at which distance to perform the test. The article you quote by Chuck Westfall recommends 50 x focal length, LensAlign recommends 25 x focal length, others have recommend testing at the distance you'll most often be photographing at ( even if it's minimum focus distance for the lens). You may get different results if you test at different distances for the same lens. With zoom lenses , you'll very likely get different results at different focal lengths. So what correction factor do you ultimately use?

I did test the AF micro-calibration and so far haven't had any AF issues with my Mk 4

[Roger Clark]

I also have never had a need for micro adjustments on any camera/lens, including D60, 10D, 20D, 30D, 40D, 1DII, 5D2, many EOS film cameras, and many lenses including 100-400, 300 f/4 L IS, 300 f/2.8 L IS, 500 f/4 L IS, and shorter lenses. The 7D looks good too but only tested it on a 180 mm macro so far. Of course many of those cameras didn't have micro adjustments, so it is good I didn't need it.

Roger

[Roger Clark]

I moved the thread to photography gear as it is discussing photo gear and not post image acquisition processing.

Roger

[Ed Cordes]

Well, I have used the micro adjustment on the 1D4 and find some of my lenses needed calibration and some didn't. I used the Morie pattern method found on North Light. I then went back and checked the calibration at a different distance on a different day and found the adjustment was still valid. I am assuming that the need for micro adjustment is not a sign of an underlying issue? I guess if it weren't OK the feature wouldn't be offered.

[Lex Franks]

Hi Jay

From whom did you order your 1D4? i'm in Toowoomba and intend to order soon. I usually use Discount Digital

Cheers

Lex Franks