Hi all,
What is lens calibration? How do we know if our lens need one? Thanks.
Hi all,
What is lens calibration? How do we know if our lens need one? Thanks.
Hi all,
What is lens calibration? How do we know if our lens need one? Thanks.
Occasionally a lens comes with a faulty internal control unit that causes mis focus.
However most people claiming they have a focus or soft focus issue do not. They use AF targets where AF does not work well and then blame the camera or lens instead of themselves. Not using cameras and lenses as the manufacturers intended on the basis of recent threads seems to outnumber camera faults by around 100 to 1.
If a lens is built of good components correctly assembled it works - apart from adjusting the infinity and minimum focus points it cannot be relcalibrated.
So what happens to all the lenses and camera bodies that go back for recalibration that in most cases probably is not needed? Generally it is cheaper for the manufacturer to check it out and maybe put a new part in than risk a law suite for telling the owner they ought to improve their photographic ability.
Occasionally a lens comes with a faulty internal control unit that causes mis focus.
However most people claiming they have a focus or soft focus issue do not. They use AF targets where AF does not work well and then blame the camera or lens instead of themselves. Not using cameras and lenses as the manufacturers intended on the basis of recent threads seems to outnumber camera faults by around 100 to 1.
If a lens is built of good components correctly assembled it works - apart from adjusting the infinity and minimum focus points it cannot be relcalibrated.
So what happens to all the lenses and camera bodies that go back for recalibration that in most cases probably is not needed? Generally it is cheaper for the manufacturer to check it out and maybe put a new part in than risk a law suite for telling the owner they ought to improve their photographic ability.
Just sent my lens for calibration to correct the back focus issue.
Came back a tad bit better but still a little back focus present. Read up a little and some website say the 24-70 has a little back focusing issue at 70mm.
Should i send it back to CSC for re-calibration since its still under the 3 months warranty?
Just sent my lens for calibration to correct the back focus issue.
Came back a tad bit better but still a little back focus present. Read up a little and some website say the 24-70 has a little back focusing issue at 70mm.
Should i send it back to CSC for re-calibration since its still under the 3 months warranty?
Might help. But what is your camera model anyway, some of the newer model could let you do some micro-adjustment to your lens too. So you can actually do your own lens calibration.
I think zoom lens is harder to calibrate? It might need certain adjustment at different range. Best to use manual focus.
I think zoom lens is harder to calibrate? It might need certain adjustment at different range. Best to use manual focus.
Hope you can explain, how using manual focus will improve the situation of AF accuracy. How do you determine if something is in focus or out of focus when doing manual focus?
Well... using manual focus could help if AF is not accurate... it would all be up to the photographer's own judgement then. Using the liveview, we could zoom in on the subject, then manually focus until the subject in question is sharp. This would be difficult I would admit, and need some time to get used to, but it can be done...
The above photos are taken using my 7D paired with my industar 50-2 50mm f3.5 lens (manual lens so there is no AF in this case)...
So when using manual focus, the only way to get accurate focus is to use Liveview. So what happens to times when one needs to capture moments, or shoot events or something that moves faster?
I never say the only way is to use liveview. But I find that liveview certainly help
And it is difficult, I admit for manual focusing... there are a couple of tricks that people had been using, one of them was to pre-focus on an area and if something walked into that area... 'click' and you got it. Use a deeper DOF for that...
In difficult lighting condition, you might want to use a flash.
I can see people using manual lens for birding, and before AF came into existence, people are using manual focus and still get good results. I believe that you can do it if you practiced enough.
(the undermentioned had been taken by my Sigma 28mm f2.8 Mini Wide II manual lens)
(here... I sneak up this aunty, who was too engross with her food, do some quick focusing and take the shot when I find the image relatively sharp in my viewfinder - using some more recognisable items like the wording on her chair as a focus point to check my focus, then use a deeper DOF and shoot, it was a hit or miss, because as soon as I took the shot, she noticed me and looked up at me crossly... hehehe)
I think zoom lens is harder to calibrate? It might need certain adjustment at different range. Best to use manual focus.