I see there is a thread related to FoCal which was sort of taken over by people who use FocusTune. However, after reading the whole thread I'm not 100% sure about which one is better/more useful. Also I do not have LensAlign, so I would have to use both with a printed target.
I would appreciate if people could share their opinions on each or both. Is possible - list pros and cons you have experienced. Would you buy it again?
Thanks to everyone who's willing to share the experience.
#1. "RE: FoCal or FocusTune?" In response to Reply # 0
I can't speak for FocusTune as I don't have it but I have FoCal (Pro) and find it useful albeit a bit too tedious in use. How much practical benefit one have over a simpler system like Lens Align, etc, I have doubts about. AF fine tuning is a moving target where varying focus distance yields different AF fine tuning needs. Nothing is perfect I guess.
#3. "RE: FoCal or FocusTune?" In response to Reply # 2
To check for left-middle-right AF discreprencies FoCal is a good tool. My experience is that several runs of the same test need to be done in order to get a good feel/measurement of the actual performance. Another, very important issue is to make sure the focus chart is well and stably lit. For the multipoint thest, I've made my own simple focus charts that are at least as good as FoCal's own (see below). The one weakness with the multifocus target from FoCal is the repeated pattern (like an QR code image) which the outer vertical sensitive sensors don't like very much. To check for AF accuracy a simpler tool is just as good IMO. I always do AF tune at a few, typical working distances for individual lenses. Then I compromise to achieve a "good enough" adjustment and save that in the camera's AF fine tuning menu.
#8. "RE: FoCal or FocusTune?" In response to Reply # 5
>...what method would you use to get the camera sensor exactly >parallel to a flat focus chart?
An alternative method is to fix a piece of flat mirror glass temporarily over the centre of the chart. Looking through the viewfinder (or using live view), align the camera so that the reflection of the lens is exactly centred in the frame. Then remove the mirror.
#10. "RE: FoCal or FocusTune?" In response to Reply # 0 Sun 18-Nov-12 12:36 AM by klrbee25
I've been using FoCal and it does what it's advertised to do. However, this lens fine tuning has so many variables and factors that it's really not very realistic. For example, if you need a perfect target that's perfectly illuminated to get accurate, repeatable results...what do you think your AF system is doing during 'real world' shooting? It's probably all over the map.
So I've resorted to using FoCal to get a very general idea of how my camera and lenses are performing (discovering sharpest apertures, best AF points in the camera, etc). However, unless things are dramatically skewed, I now keep AF fine tune off.
#11. "RE: FoCal or FocusTune?" In response to Reply # 10
I have purchased and used both products. I didn't have the lensalign fixture so I used a printed target. I lit the target with two 500watt soft boxs. I calibrated two cameras D800E and a D700 with 11 lenses on the same tripod using the same light source. I found both software packages will do the job. But there were some differences,
1. Semi automatic ( still have to change the AFA numbers by manually) 2. Nice print out with the graphs and data points. 3. Automatic defocus between shots.
1. No mirror lockup 2, Needed a lot of light 3. Inconsistant results, difficult to get repeatable results, not always reliable.
1. Consistant results, repeatable across the graph, few outliers. 2. Nice print out with the graphs and data points. 3. Mirror lockup is available ( I believe this is the main reason for the consistant results) 4. Don't need the computer tethered to the camera, can shoot the data points and then load to the computer.
1. No auto focus detune between data points, must be done manually 2. AFA must be changed manually.
I didn't test FocusTune with the LensAlign fixture, I don't have the fixture. From reading other reviews it works better with the fixture. I have to say I was impressed with the results from FocusTunes, especially the repeatibility. It gives you confidence in the results, which is why I looked for another solution after buying FoCus. I couldnt get the software to give me results that I could repeat. FocusTune is not perfect, its harder to use , you have to do more of the work but in the end its worth it to get results you can feel confident in. And finally its cheaper !
I have no connection with or even know the two folks that produce these two pieces of software other than I paid them both for thier products.
#12. "RE: FoCal or FocusTune?" In response to Reply # 11
Thanks for sharing! A little too late for me - I purchased FoCal using that discount price I mentioned above. Well, I will test my camera using it and then see if I want/need to pay for FocusTune. It's a bummer to hear that FoCal needs a lot of light and doesn't support mirror lock up.
My main reason for purchasing is to continue dealing with my D800 focus issue.
#14. "RE: FoCal or FocusTune?" In response to Reply # 11 Tue 20-Nov-12 12:11 PM by richardd300
<<I didn't test FocusTune with the LensAlign fixture, I don't have the fixture. From reading other reviews it works better with the fixture>>
I didn't use FocusTune standing alone, but with Lens Align. I used high wattage lighting Mup, remote release and everything locked down for stability even then I had to repeat many tests to achieve better repeatability, but even now I am extremely suspicious of some results.
As I have posted on other forums and I'm sure folks are getting pretty sick of me saying it, but my issue is with both FocusTune and LensAlign and any other test method with zoom lenses. However, I repeat my concerns here for completeness!
"No one has really persuaded me that zoom lens errors can be coped with by any angled tests unless either a permanent focal length is used, or perhaps a decided average of staged tests across the full focal length will make an overall improvement".
I really do think that the whole issue of AF-Fine tune needs it's own forum so all collective posts can reside in a single reference
#17. "RE: FoCal or FocusTune?" In response to Reply # 14
Richard, I saw all of your posts and read online about AF fine tune for zoom lenses. Yes, unfortunately, it is a compromise. I have hard time understanding how one can select a single focal length for a zoom based on their uses, but at least testing you can see how the lens behaves and whether it is within reasonable margins. Also you can adjust it to give you better results that it provides now, which also would be a good thing. Not ideal, but better than with no adjustments in case when a lens needs a lot of AF fine tuning.
Btw, what kind of lighting did you use when testing?
#18. "RE: FoCal or FocusTune?" In response to Reply # 17 Tue 20-Nov-12 04:31 PM by richardd300
I used a 300 watt halogen floodlight which nearly blinded me. I had used LED lights but the light I felt was not as good
I do agree that with considerable effort a zoom can be treated to a "compromise setting" by e.g. checking my 24-70mm at 24, 40, 55 and 70mm and then calculating an average setting. However, I am not sure where the fine tune setting should be decided on. I tested at 24, 45 and 70mm and got all + fine tune requirements +15 (24mm), +5 (45mm) and +10 (70mm). So I knew the lens was front focusing. So I ran a test at 45mm from 0 - +10, the result was +5. In the end I decided on an average of +7 as a half way house.
I re-ran the test throughout the same focal values, but instead at the closest FocusTune distance, 50% of maximum (because the distance tool told me to use the long ruler, which I didn't have). The results were not even comparable to the first results with +20, +15, +18!!!! At that point I must admit I gave up for now and returned the AF-fine tune to zero
#19. "RE: FoCal or FocusTune?" In response to Reply # 18
San Diego (Bonita), US
>I do agree that with considerable effort a zoom can be treated >to a "compromise setting" by e.g. checking my >24-70mm at 24, 40, 55 and 70mm and then calculating an average >setting. However, I am not sure where the fine tune setting >should be decided on. I tested at 24, 45 and 70mm and got all >+ fine tune requirements +15 (24mm), +5 (45mm) and +10 (70mm). >So I knew the lens was front focusing. So I ran a test at 45mm >from 0 - +10, the result was +5. In the end I decided on an >average of +7 as a half way house. > >I re-ran the test throughout the same focal values, but >instead at the closest FocusTune distance, 50% of maximum >(because the distance tool told me to use the long ruler, >which I didn't have). The results were not even comparable to >the first results with +20, +15, +18!!!! At that point I must >admit I gave up for now and returned the AF-fine tune to zero >
I know it's been a while, but I decided after too many out of focus shots on my last outing that I need to calibrate my lenses, hence dredging up this old thread! Thank you so much for your experimentation and analysis. I think I'm probably going to go with FocusTune thanks to the price and consistent results. The graphs sure are pretty!
I don't know about your repeat test's odd results... maybe you really need the long ruler or some functional equivalent. But as to the question of where to adjust the fine tune for zooms, I read one post (preview.com, I think) that made a lot of sense: adjust it to the correction for the longest focal length, where the relative DOF is shallowest.
Or.... always use live view & contrast detect AF and forget about calibration!