Lens align pro or Spyder lenscal

[Dylan777]

I'm thinking about Reikan FocCal Pro, do they provide setup distance for each lens?

You choose the distance. Canon recommends 50x the focal length, LensAlign recommends 25x the focal length (i.e. about 16' and 8' for every 100mm of focal length, respectively).

Personally, I test all lenses at both 25x and 50x the focal length (and multiple focal lengths for zooms, wide, tele and 1-3 in between), then look at the overall results to decide the AFMA value(s). It's going to be a compromise, more data drives a better decision. I take into account the subject distances with the lens (close for the 85L, far for the 100-400, etc.), the usual DoF (weight close distance more with wide lenses). It means lots of testing, which is why the automation is great.

Neuro,
To make sure I understand you correctly(50X):

1. 50mm f1.4 ==> 50 x 50mm = 2500mm(8.2 ft) distance from chart to camera

2. 16x35 ==> wide end: 50 x 16mm = 800mm( 2.6ft) distance from chart to camera
==> zoom end: 50 x 35mm= 1750mm(5.7ft) distance from chart to camera

am I on the right track?

 

[Loswr]

@ Dylan777 - absolutely correct.

 

[DynaMike]

Everyone is leaving good info here! I use the lens align. It works, but is kind of a pain in the ass to align. Setting up a 400mm on a 7D at 50x length involves a lot of walking back and forth from target to camera making small adjustments and checking. Takes a while to set up in those situations, and then there's going through the images and deciding what's correct. Gets time consuming, so as soon as the Mac version of FoCal is released; I'm on it! Sounds like a better/ easier system to me.

 

[Loswr]

It works, but is kind of a pain in the ass to align. Setting up a 400mm on a 7D at 50x length involves a lot of walking back and forth from target to camera making small adjustments and checking.

There's still tweaking to align to the FoCal target, but the advantage is the target is flat (e.g., taped to a wall), and you're aligning the camera based on input from the computer via tethering. No more walking back and forth!

 

[Dylan777]

@ Dylan777 - absolutely correct.

Thanks Neuro

 

[nismohks]

lots of great info here!

would the Plus version allow for multiple focal length testing for each lens?

Im just deciding between the Plus and Pro, but decided that i dont really need any of the benefits afforded by the Pro. The most important thing for me is that as long as i can test the AFMA at multiple focal ranges of each lens (as mentioned by several users above) then that would be the choice for me.

 

[Loswr]

You set the focal length for zooms, and you pick the distance.

 

[kaihp]

No more walking back and forth!

I still have to walk/move between the tripod and the laptop screen when aligning the target. I'm colorblind and the on-screen markers are nigh impossible for me to see even 3' away. I've fed back to FoCal to add more color/saturation/contrast to make the markers more visible from the distance. Also bigger AFMA numbers for when using the semi-manual mode with the 5D3 (and 1Dx).

What kind of peak QoF figure do you guys get, and how narrow is the peak around the max QoF?
My peaks are quite flat and with my5D3 and the 70-200/2.8L IS Mk I I get around 1000 @ 6meters and 1300 @ 2meters.

 

[Phenix205]

I would recommend FoCal Pro. I've been getting inconsistent results for some of the older lenses such as 28-70 and 50 1.4. Following Neuro's recommendations, I've been testing all lenses at 25x and 50x focal length. In real life shooting, it may not make too much difference if you are within +/- 10.

 

[Loswr]

I've been testing all lenses at 25x and 50x focal length. In real life shooting, it may not make too much difference if you are within +/- 10.

If you mean within +/- 10x of focal length distance, probably true.

If you mean within +/- 10 AFMA units, I'd expect that to make a difference in many situations, either shooting wide open or with close subjects. One unit is 1/8 the depth of focus at max aperture, so a 10-unit difference is substantial. A 1-2 unit difference can be noticeable with an f/1.2 or f/1.4 prime, on average, but any given shot will vary a little too, probably in a similar range. A 3-4 unit difference with an f/4 or f/5.6 lens is probably not too noticeable.

 

[kaihp]

If you mean within +/- 10 AFMA units, I'd expect that to make a difference in many situations, either shooting wide open or with close subjects.

Shooting at f/2.8 on 2 meters distance, being 5 AFMA units just spoils the image because the focus is not where you want it like the attached a 50% crop where focus is not on the eye, but on the body of the duck.

 

[hoghavemercy]

I've been testing all lenses at 25x and 50x focal length. In real life shooting, it may not make too much difference if you are within +/- 10.

If you mean within +/- 10x of focal length distance, probably true.

If you mean within +/- 10 AFMA units, I'd expect that to make a difference in many situations, either shooting wide open or with close subjects. One unit is 1/8 the depth of focus at max aperture, so a 10-unit difference is substantial. A 1-2 unit difference can be noticeable with an f/1.2 or f/1.4 prime, on average, but any given shot will vary a little too, probably in a similar range. A 3-4 unit difference with an f/4 or f/5.6 lens is probably not too noticeable.

why would it compute on a suggested number when other AFMA scored higher, eg AFMA=3 1645 AfMA=4 1605 AFMA=5 1637 and it picks 4 about 6 to 8 ft from the chart it's pretty accurate but just concern if that's a problem, on the 5DIII it's manual only just wondering if there's a patch or an update.

 

[Loswr]

why would it compute on a suggested number when other AFMA scored higher, eg AFMA=3 1645 AfMA=4 1605 AFMA=5 1637 and it picks 4 about 6 to 8 ft from the chart it's pretty accurate but just concern if that's a problem, on the 5DIII it's manual only just wondering if there's a patch or an update.

Because its fitting a curve based on multiple measurements over a wider range, which is a better approach than using the single highest measurement. There is variability in the AF system, slight differences each time you refocus on the same point. The curve fitting helps pick the best value despite that variability.

 

[hoghavemercy]

why would it compute on a suggested number when other AFMA scored higher, eg AFMA=3 1645 AfMA=4 1605 AFMA=5 1637 and it picks 4 about 6 to 8 ft from the chart it's pretty accurate but just concern if that's a problem, on the 5DIII it's manual only just wondering if there's a patch or an update.

Because its fitting a curve based on multiple measurements over a wider range, which is a better approach than using the single highest measurement. There is variability in the AF system, slight differences each time you refocus on the same point. The curve fitting helps pick the best value despite that variability.

Thanks for that. I'm learning something new everyday.

 

[Andy Jazz]

Just a quick question. When I have calibrated the centre af point on my 1dx should all the Af points be correct?As they all forward focus.

 

[Loswr]

Just a quick question. When I have calibrated the centre af point on my 1dx should all the Af points be correct?As they all forward focus.

In theory, yes. But FoCal can actually test them all to confirm...