Rumors > Lenses

600mm F/4L IS AFMA settings

(1/8) > >>

East Wind Photography:
Can anyone provide guidance on their AFMA settings used with their 600 F/4L IS?  I primarily am using a 5DMIII now.

Also If you've used Focal to calibrate your AFMA settings, what target distance and size has worked best for you?  I have had issues getting the software to finish a test and my thoughts are perhaps I am out too far for the software to properly analyze the target.  Curious as to others experience.

neuroanatomist:
I test all lenses at both 25x and 50x the focal length, and I use the standard FoCal target.  So, for a 600mm lens that's 49 ft (15 m) and 98 ft (30 m).  Since I'm using a multiple of the focal length, the target size in the image is the same with any lens (e.g. 24mm at 3.9' is the same FoV as 600mm at 98'). 

I suspect your problem is either having too much vibration and/or not having enough light.  How stable is your setup and what was the EV reported for the test?

When I first started using FoCal, I ran tests on the main floor of my house (hardwood floors), and I had several failed tests.  I moved the setup to the basement (concrete slab) and had none.  Also, I use lots of light - I point three 150 W-equivalent gooseneck lamps at the target from a distance of 12-14", and my reported EVs are in the 11-12 range when I test indoors.  For my 600/4 II, I ran the test outdoors in direct sunlight, and still had the 3 150 W-equivalent lamps pointed at the target, so my EVs were in the 15-16 range.  That gave me shutter speeds of 1/1250 s with the f/5.6 combo with the 1.4xIII.  I still haven't done the 600 II with the 2xIII testing - I need to find a vacant football field for that...

wearle:
I just calibrated my 600mm f/4.0L IS II today using the latest, non-beta, version of FoCal.  I repeated each test twice and got the exact same results each time.  I used two 500-watt light bulbs indoors and got EV's between 11-12.  My ISOs varied between 200-400 with the 1DX as I was forcing a shutter speed no less that 250.  I'm not sure if this was necessary given it was mounted on a sturdy tripod.  I may at a future time try lower shutter speeds to keep with an ISO of 100.  Here are my results:

1DX

600mm   +6
840mm (with 1.4X II)   -1
1200mm (with 2.0X III)   -7

5D2

600mm   +6
840mm (with 1.4X II)   -2

I was really surprised with the consistency I got between the two cameras.  I'm positive it was just coincidence. ;)

Wade

rpt:
Neuro and wearle are on the money. The only thing I'd add is DO NOT USE FLUORESCENT LAMPS OR TUBES. Sorry for shouting it out but it has been one of the significant reasons my tests failed. Also never raise the central column of the tripod.

Best of luck :)
 

weekendshooter:

--- Quote from: rpt on November 20, 2012, 09:45:44 PM ---Neuro and wearle are on the money. The only thing I'd add is DO NOT USE FLUORESCENT LAMPS OR TUBES. Sorry for shouting it out but it has been one of the significant reasons my tests failed. Also never raise the central column of the tripod.

Best of luck :)

--- End quote ---

Every single light in my apartment is fluourescent... No wonder FoCal kept giving me inconsistent results. Good to know! I might pick up some cheap lights and then return them afterwards.

Navigation

[0] Message Index

[#] Next page

Go to full version