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Gear Talk => Lenses => Topic started by: dvky on March 04, 2013, 02:45:47 PM

Title: Camera & Lens Focus Calibration
Post by: dvky on March 04, 2013, 02:45:47 PM
Hello

I am sorry if this topic has been mentioned in another thread previously but I'd wanted to confirm this from photographers that actually use and take pictures daily professionally and print them as fine art for the final product.

How important and off or spot on are the camera and lenses focus that you buy?

For example, a canon 5d mk 3 w/ 70-200mm f/2.8 IS II, 50mm f/1.4, 85mm f/1.2, 24mm f/1.4

I am aware that there may be some difference depending on the lens and camera coming out straight from the factory
and may have some minor change during handling, etc

But my current boss insists that the camera and ALL the lenses must be focus calibrated to get that spot on autofocus.
And I have tried finding a store that would do that kind of pin focus service but haven't been quite successful.
Would CPS have that kind of service? or will there be another retailer that offers this ind of service?

I'm sure there are bound to be margin of error in spot on autofocus with different lenses due to various reasons but buying from B&H, Amazon, or Adorama, etc will have such problems?
Micro-adjustments seems to be general answer but I'd appreciate if someone would know of such service.

My boss gets his camera and lens focus service done in Korea but I'm currently trying to buy a 5d mk3 in NYC.
Since my need to purchase this camera is urgent I'd greatly appreciate for some helpful answers.

Thanks in advance to everyone.

Dave
Title: Re: Camera & Lens Focus Calibration
Post by: neuroanatomist on March 04, 2013, 04:06:03 PM
AF microadjustment is the DIY solution, but do it properly with software like Reikan FoCal or a commercial tool like LensAlign.

Yes, CPS will do it - in fact, that need (which far predates AFMA as a feature) is one of the reasons that CPS came into existence.
Title: Re: Camera & Lens Focus Calibration
Post by: Mt Spokane Photography on March 04, 2013, 04:38:33 PM
CPS or any of the very few Authorized Canon Service centers will do it.  Like Neuro said, Reikan Focal can be used  make adjustments at one focal distance for primes, and two focal lengths at one distance for zooms.
Canon may be able to adjust a lens at different distances and focal lengths depending on the lens.  However, you might have to pay for a super fine adjustment if the lens/camera combination already meets specifications.
Title: Re: Camera & Lens Focus Calibration
Post by: AKChui on March 04, 2013, 04:44:16 PM
I'm adjusting DIY (so results are approximate), and have found that my 5D3 and two 5D2s are all focusing in front by 1-2 inches for just about every Canon lens I own.  IMHO it is worth the effort, but for everyday users, any mis-focus is probably inconsequential.
Title: Re: Camera & Lens Focus Calibration
Post by: RGF on March 04, 2013, 06:26:07 PM
AF microadjustment is the DIY solution, but do it properly with software like Reikan FoCal or a commercial tool like LensAlign.

Yes, CPS will do it - in fact, that need (which far predates AFMA as a feature) is one of the reasons that CPS came into existence.

Has one use the Reikan FoCal?  How much time is required to calibarate each prime/body pair?  What about a zoom?  Can telephotos be calibrated (300+ mm or longer)?  Has one tried calibrating with converter on a telephoto?

If I lived closer to NJ I would drop all my stuff at Canon to have them check it out.
Title: Re: Camera & Lens Focus Calibration
Post by: neuroanatomist on March 04, 2013, 08:15:27 PM
FoCal takes me less than 10 minutes per test.  I run several tests per lens - distance of 25x and 50x the focal length, zooms tested at both ends and 1-3 intermediate focal lengths (more for higher zoom ratios).  I've done my 600/4 bare and with the 1.4xIII; I haven't done it with the 2xIII yet as I need to find a vacant football field...
Title: Re: Camera & Lens Focus Calibration
Post by: dvky on March 04, 2013, 10:10:14 PM
Thanks for the awesome and helpful feedback guys!
I guess i'll try the CPS silver membership and also try DIY with older body and lenses. :D
Title: Re: Camera & Lens Focus Calibration
Post by: RGF on March 04, 2013, 10:19:15 PM
FoCal takes me less than 10 minutes per test.  I run several tests per lens - distance of 25x and 50x the focal length, zooms tested at both ends and 1-3 intermediate focal lengths (more for higher zoom ratios).  I've done my 600/4 bare and with the 1.4xIII; I haven't done it with the 2xIII yet as I need to find a vacant football field...

600 mm plus 2x at 10x focal length is 12 meters or about 40 feet.  Perhaps a hallway in a house, definitely hard to find a room that big in my house
Title: Re: Camera & Lens Focus Calibration
Post by: neuroanatomist on March 04, 2013, 10:26:38 PM
FoCal takes me less than 10 minutes per test.  I run several tests per lens - distance of 25x and 50x the focal length, zooms tested at both ends and 1-3 intermediate focal lengths (more for higher zoom ratios).  I've done my 600/4 bare and with the 1.4xIII; I haven't done it with the 2xIII yet as I need to find a vacant football field...

600 mm plus 2x at 10x focal length is 12 meters or about 40 feet.  Perhaps a hallway in a house, definitely hard to find a room that big in my house

10x is generally too close, should be 25-50x.  I will test the 600+2x at 30 and 60 meters (100 and 200 ft).
Title: Re: Camera & Lens Focus Calibration
Post by: scottkinfw on March 04, 2013, 10:29:15 PM
each camera and each lens is not set to an exact point, but rather to exact tolerances.  As such, you may get a camera and lens combination that is perfect, but likely as not, not.  Think of it this way.  Say a the camera is within spec but at the low extreme, and the lens on the other hand is within spec but at the high end of the extreme.  Although both within spec, together, they will not produce an optimal pic. 
Even if you get good pics without calibrating, you may not be getting the best that your most excellent equipment can deliver.  That is why the AFMA is offered.

I lost confidence in Canon doing the calibration when I shipped my gear to them for calibration prior to a photo safari in August.  When I realized that the pics were at all focused well, I had to make adjustments in the field.  Much better and fortunately, did get some keepers.  Sadly, lost some great, never to capture again pics.
Title: Re: Camera & Lens Focus Calibration
Post by: East Wind Photography on March 04, 2013, 10:32:05 PM
You need big spaces for long teles.  Vibration will also skew your results.  The longer the focal length the harder it is to get FoCal to give you consistent results.  Ive given up testing any of my lenses longer than 300mm.  I calibrate them manually using a lensalign setup.

New stuff though has come out with the latest version so I might give it a try again when this snow gets out of here.

FoCal takes me less than 10 minutes per test.  I run several tests per lens - distance of 25x and 50x the focal length, zooms tested at both ends and 1-3 intermediate focal lengths (more for higher zoom ratios).  I've done my 600/4 bare and with the 1.4xIII; I haven't done it with the 2xIII yet as I need to find a vacant football field...

600 mm plus 2x at 10x focal length is 12 meters or about 40 feet.  Perhaps a hallway in a house, definitely hard to find a room that big in my house
Title: Re: Camera & Lens Focus Calibration
Post by: RGF on March 04, 2013, 10:32:34 PM
FoCal takes me less than 10 minutes per test.  I run several tests per lens - distance of 25x and 50x the focal length, zooms tested at both ends and 1-3 intermediate focal lengths (more for higher zoom ratios).  I've done my 600/4 bare and with the 1.4xIII; I haven't done it with the 2xIII yet as I need to find a vacant football field...

600 mm plus 2x at 10x focal length is 12 meters or about 40 feet.  Perhaps a hallway in a house, definitely hard to find a room that big in my house

10x is generally too close, should be 25-50x.  I will test the 600+2x at 30 and 60 meters (100 and 200 ft).

My error.   25-50x would be about half a football field.  You were not kidding about the distance required.   Garbage on the alley to house is only about 100 feet.  Need a bigger yard
Title: Re: Camera & Lens Focus Calibration
Post by: RGF on March 04, 2013, 10:35:26 PM
You need big spaces for long teles.  Vibration will also skew your results.  The longer the focal length the harder it is to get FoCal to give you consistent results.  Ive given up testing any of my lenses longer than 300mm.  I calibrate them manually using a lensalign setup.

New stuff though has come out with the latest version so I might give it a try again when this snow gets out of here.

FoCal takes me less than 10 minutes per test.  I run several tests per lens - distance of 25x and 50x the focal length, zooms tested at both ends and 1-3 intermediate focal lengths (more for higher zoom ratios).  I've done my 600/4 bare and with the 1.4xIII; I haven't done it with the 2xIII yet as I need to find a vacant football field...

600 mm plus 2x at 10x focal length is 12 meters or about 40 feet.  Perhaps a hallway in a house, definitely hard to find a room that big in my house

Other the difficulty of supertelephotos, is it worth the investment.    I am trying to get off the accessory (and bag) of the month club.   Need more than 12 steps to get off those habits
Title: Re: Camera & Lens Focus Calibration
Post by: Mt Spokane Photography on March 04, 2013, 10:37:33 PM
The latest version (1.8) of Reikan Focal has a Turbocal setting that will AFMA a Canon lens in 20-30 seconds.  However, some cameras like the 5D MK III are semi-automatic and will take a little longer.
 
http://www.photographytips.com/page.cfm/33 (http://www.photographytips.com/page.cfm/33)
 
I've read that the 1D MK III is not recognized, so there will be a fix to 1.8.
 
 
Title: Re: Camera & Lens Focus Calibration
Post by: woollybear on March 07, 2013, 06:57:07 AM
FoCal takes me less than 10 minutes per test.  I run several tests per lens - distance of 25x and 50x the focal length, zooms tested at both ends and 1-3 intermediate focal lengths (more for higher zoom ratios).  I've done my 600/4 bare and with the 1.4xIII; I haven't done it with the 2xIII yet as I need to find a vacant football field...

Do I understand you correctly...zooms...short end tested at 25x and 50x, long end tested at 25x and 50x, and intermediates tested at 25x and 50x...

So a 70-200 would involve 6-10 tests with distances ranging from 1.75m to 10m?

And the results (5diii) would be an average (mean or median?) for the low end and an average for the high end?

And if you'll indulge me one more question...you run a complete, separate series of tests when using a TC?
Title: Re: Camera & Lens Focus Calibration
Post by: surfnron on March 07, 2013, 08:00:20 AM
Over on FM, a member has come up with a dead simple way to calibrate lenses quickly. Basically you focus on your target and turn off autofucus. Then in the MA menu, you check the focus by half pressing the shutter, (or back button),and adjusting the ma setting until the focus light blinks. Do this for + and -. Your sharpest focus will be in the middle. Here is a link:

http://www.fredmiranda.com/forum/topic/1187247 (http://www.fredmiranda.com/forum/topic/1187247)

This is my first post here - hope the link works... :)

Ron
Title: Re: Camera & Lens Focus Calibration
Post by: Plainsman on March 07, 2013, 08:05:41 AM
No lens can maintain optimum sharpness right through from close range say 10m to infinity - in practice anything beyond a few hundred metres.

So ideally you need to do your AFMA for your normal approx favourite photographing distance.

Long lenses are birders lenses designed for optimum performance at relatively close range rather than infinity.

Interesting to read Thom Hogan's reviews on long Nikons and his comment that they loose some sharpness at long distance. Same probably applies to Canon.
Title: Re: Camera & Lens Focus Calibration
Post by: neuroanatomist on March 07, 2013, 08:23:33 AM
Do I understand you correctly...zooms...short end tested at 25x and 50x, long end tested at 25x and 50x, and intermediates tested at 25x and 50x...

So a 70-200 would involve 6-10 tests with distances ranging from 1.75m to 10m?

And the results (5diii) would be an average (mean or median?) for the low end and an average for the high end?

And if you'll indulge me one more question...you run a complete, separate series of tests when using a TC?

Correct.  The number of intermediate focal lengths I test depends on the zoom range, e.g. for a 2-3x zoom like the 16-35mm or 70-200mm, I test just one intermediate focal length; for a ~4x zoom like the 24-105mm or 100-400mm, I test two, etc.  So for the 70-200, that's a total of 6 tests - 70mm, 135mm, and 200mm each at 25x and 50x the focal length.

The newer AFMA bodies (including the 5DIII) can store separate values for the wide and tele ends of zoom lenses.  I use the two distances and the intermediate focal lengths to help guide the choice - the values I enter are a compromise between the distance(s) at which I usually shoot with that lens, the effect of focal length on DoF, etc.  For example, with my 100-400L at 50x focal length, the FoCal-reported AFMAs at 100,200,300,400mm were 0,0,0,1 and at 25x focal length they were -3,0,-1,2.  The values I selected were W=-1 and T=1. 

The camera does a simple linear regression between the W and T values to apply AFMA at intermediate focal lengths.

Yes, with a teleconverter I do a complete separate set of measurements (6 for the 70-200/2.8 with the 1.4x and 6 more with the 2x).