If I had existing AF fine tune values set on the camera, the tests were not as accurate, setting the AF tune values to -0- improved results with the camera bodies with ALL lenses.
I found the Focal software gave me more accurate results on the D8XX bodies if I made sure to lock in the AF on the target correctly with the AF correction set to -0- before I started the tests.Mixed results with Sigma Art lenses - most of them got a below average "fit" rating during calibration, two of the lenses (50mm and 85mm) both said they needed greater than -20 calibrations, but I found they were very accurate (focusing on an eyeball at f1.4) in the -18 to -20 correction range. Pretty good with all G lenses, make sure to calibrate zooms at the widest focal length. Pretty good with D lenses except for the 105mm and 135mm DC lenses, calibrate AF on those by hand if needed. Pretty good with all Sigma Art lenses, 24mm to 135mm tested. Solved the problem in the end, bought a sony a7r3!įorget about it with D lenses - use the target and your eyes to set the needed AF adjustment, the AF tests consistently failed with Focal using D lenses. It was just an example, I had other lenses with front or backficus issues. If you want to do it to just play around with it and do some experiment than I get it.we've all done something similar.
Just curious.If there was no identifiable problem then why try and test and adjust? Plus or minus 1-2 would likely be imperceptible unless very controlled and scientific environment and then not even sure. You are right of course, but it’s just my typo, it’s set at plus 16 which is where software wants it.my posting error How can a fine adjustment of -16 cause a back focus? Minus sixteen gets the sharpness to the near side. I have tested on real targets with a tripod at a variety of distances, and the -16 setting is clearly way out.Īny ideas? Does Focal work for other people? I am only testing the centre point at this time. in everyday use (albeit a new lens to me) there was no identifiable problem, and I was expecting at most a plus or minus 1 or 2 for real fine tuning. The test was run 3 times and gave completely consistent readings of -16 adjustment, however when that is dialled in, the lens is clearly backfocussing, probably by that amount ar thereabouts - i.e. Starting with my art 35mm, the focal setup is exactly as prescribed, very careful placement, lighting, distances etc.
I just bought Focal Pro to test and tune my sigma lenses. I also got tired of Focal and upgrades - I only use it with new cameras and new lenses, and it seems every time I needed it (ever couple years) I needed to get an upgrade. at the focal length and distance, as well as close and far and in and out to see how it varies, but give a lot of weight to the place you use it. I'm a big proponent of testing it where you use it, i.e. Some lenses (my 85/1.4 is awful) are significantly different for close and far. Some zooms are significantly different zoomed in and out. It's also worth saying that there is NO correct AF Fine tune for some lenses. I can SEE the DOF range move as I adjust, so I can tell (for example) if it's moving consistently, or not (some lenses just plain do not consistently focus, and you have to do a lot more tests to see where the average DOF area is). I can SEE the DOF range, not just that I have a soft image. Not because it is inherently better, but because it is more natural from a human standpoint. You can run a longer and more thorough test, and it may be worth trying.Īll that said, over time I have migrated to more slant-view approach as well (e.g. The issue is that lighting variations get mistaken for focus variations (shouldn't, but did at least at the time).Īnother issue is that over time they have gotten more aggressive at prediction. My best luck was with a couple droplights lighting the target indoors. if there are ever any cloud variations, will not work. Lighting is a big deal - you need good, contrasty lighting and a very stable target (I found this to be an issue when trying to test really long lenses outside). I used it some years ago and got quite good results on most lenses, and learned a lot about them.