FoCal...effective? Worth it?

Bakewell wrote in post #16424483
Maybe I'm being too picky but any of eight choices (out of twenty) isn't acceptable to me...

What, even if those choices are indistinguishable?

In effect you're saying, why even bother to MF in the first place since the margin for error is so great...eight points out of twenty(at least). I disagree and suggest that points to a deficiency in the software.

Bakewell wrote in post #16425929
In effect you're saying, why even bother to MF in the first place since the margin for error is so great...eight points out of twenty(at least). I disagree and suggest that points to a deficiency in the software.

Which might make sense, if it weren't for the fact that I get the exact same results when I test that particular lens manually.

But you're right on one point - for the vast majority of camera/lens combinations an MFA value of zero will give a result indistinguishable (without analysis by specialist software) from the values of 2 or 3 that most people seem to report.

Where MFA does come in handy is the odd lens that isn't quite right. My 100mm macro, for example, is the only lens I've tested that needs an MFA value outside the range -3 to +3 all the rest are perfectly good with an MFA setting of zero.

And that shouldn't be surprising to anybody who's spent more than 2 seconds thinking about it.

Bakewell wrote in post #16425929
In effect you're saying, why even bother to MF in the first place since the margin for error is so great...eight points out of twenty(at least). I disagree and suggest that points to a deficiency in the software.

Without knowing the lens and the aperture being tested you can't really come to any conclusion.

I've tested a few lenses and most of the time they've given the same results. Where the results have been different (and at times frustratingly so) I think it's been caused by lighting and temperature differences. It's definately best to avoid cloudy conditions and probably best to avoid direct sunlight (I've not really tested that yet)

My most frustrating early experience was with a 100mm macro and I just couldn't get a repeatable result...it turned out there was a dirty great fingerprint on the lens (I blame my kids).

Even after micro adjusting I often still do a quick and dirty dot tune check at location to make sure things are working as I expect they should.

Australuan temperature extremes do seem to have an impact on the MFA required.

hollis_f wrote in post #16426011
But you're right on one point - for the vast majority of camera/lens combinations an MFA value of zero will give a result indistinguishable (without analysis by specialist software) from the values of 2 or 3 that most people seem to report.

I tend to agree though with thin DOF shots a +/- 3 can make a difference.

The only lens I need to adjust is my 70-300L which is out by +6 and with my kenko 1.4x is out by -10. Those are amounts which can render a shot pretty much useless.

Given that +/- 2 or 3 usually provides sharp images you can probably get within those tolerences by using the dot tune method...and it's free.

I love FoCal, the software is very easy to use and very fast.

hollis_f wrote in post #16424369

Slightly off topic, but when I was running my 24-70 f2.8L mk1 and 70-200 f2.8L IS mk2 through the system the highest "Quality of Focus" values I were seeing were the high 700s to mid 800s.

Seeing this chart, and some others with values approaching 2000 are my Quality of Focus values off? I'm fairly sure I have the target set up with adaquete lighting (10-10.5EV), would that make a difference?

mccamli wrote in post #16426060
I tend to agree though with thin DOF shots a +/- 3 can make a difference.

Yes, I guess it could. However, I try to follow the instructions and use 30x to 50x the focal length. Doing so makes the DoF quite deep.

If their was so much latitude I question why Canon would offer 20 different adjustment points? I would six or so would suffice.

Bakewell wrote in post #16426288
If their was so much latitude I question why Canon would offer 20 different adjustment points? I would six or so would suffice.

They don't offer 20 adjustment points, they offer 41. Software solutions like FoCal can provide a much more accurate estimation of the correct MFA value when it has a lot more data points to work with. I guess the people that designed the algorithms, being engineer-types, decided to go all-out and have it slightly more accurate than is really necessary.

Anybody who looks at the graphs produced by FoCal pro - and understands maths/science - can easily tell when the software is producing sensible, reliable results.

hollis_f wrote in post #16426390
They don't offer 20 adjustment points, they offer 41. Software solutions like FoCal can provide a much more accurate estimation of the correct MFA value when it has a lot more data points to work with. I guess the people that designed the algorithms, being engineer-types, decided to go all-out and have it slightly more accurate than is really necessary.

Anybody who looks at the graphs produced by FoCal pro - and understands maths/science - can easily tell when the software is producing sensible, reliable results.

Of course you are correct about the 41, makes more sense than 20... I was thinking on each side of 0. And of course if I "understands maths/science" I would certainly see the error of my ways and appreciate this software. I stand corrected (sorry for the rather snide reply but your posts tend to be rather patronizing in general). If only I was a "retired spectroscopist".

BodyResults wrote in post #16423770
Are they still responding to support issues?

I have posted two and have not heard back after a 4-5 weeks. I own the pro version and have used it successfully on the 7D and 5D3 but am having some issues connecting to the 1Dx to get the process going.

They have not replied to my issue posted at least a month ago and three emails to follow-up. Very disappointing. Once I would highly recommend. Now not so sure, but it does do better than I can do manually.

~Bob

rebop wrote in post #16426878
They have not replied to my issue posted at least a month ago and three emails to follow-up. Very disappointing. Once I would highly recommend. Now not so sure, but it does do better than I can do manually.

~Bob

My guess it that they are struggling to survive. Version 2 is free to all current owners. A sure sign of problems. Their site has been rather static for months. There has just been too many problems concerning their software that they can't address. Even if you do understand charts and graphs...