Originally posted by DimC I agree it's kinda sad there is not video about fixing the infinity on this lens. Im very bad at fixing things like that, I'd prefer to see to tutorial first
Im planning on doing nightscape photography around may6th and I'm very happy to try this Irix then.
At first I thought my infinity lock was out, but after trying different shots I think it's correct, how would you test Infinity focus btw ?
In practical terms I think you can set the focus ring at the infinity click stop then check the focus of some distant high contrast object with the live view screen with full magnification. Here are some numbers for the 15mm lens ...
Assuming a
Circle of Confusion of 0.02mm
At F/2.4 the hyperfocal distance is 15.6 feet :: Objects from 7.79 feet to infinity will be in acceptable focus
At f/4.0 the hyperfocal distance is 9.2 feet :: Objects from 4.64 feet to infinity will be in acceptable focus
At f/5.6 the hyperfocal distance is 6.57 feet :: Objects from 3.29 feet to infinity will be in acceptable focus
At f/8.0 the hyperfocal distance is 4.66 feet :: Objects from 2.33 feet to infinity will be in acceptable focus
At f/11.0 the hyperfocal distance is 3.32 feet :: Objects from 1.66 feet to infinity will be in acceptable focus
At f/16.0 the hyperfocal distance is 2.36 feet :: Objects from 1.18 feet to infinity will be in acceptable focus
If you assume a different circle of confusion you need to recalculate the numbers. You can do it here ...
DOFMaster
Cheers,
Rick
---------- Post added 04-08-18 at 08:37 AM ----------
In the IRIX 15mm User Manual they say ...
To calibrate the focus ring:
1. Remove the calibration window cover by unscrewing the T6 Torx screw and sliding the cover outward.
2. Set the focusing ring at the infinity position and rotate the focus lock ring to the locked position. The internal calibration ring and flat head locking screw should be visible.
3. Using a flat head screwdriver, loosen the screw on the calibration ring. Be careful not to allow the screws to fall into the lens housing. A screwdriver with a magnetic tip is recommended.
4. Using your camera’s Live View and LCD zoom, rotate the calibration ring to focus carefully on a distant subject (
farther away than 50m/164ft).
5. Lock the calibration ring by re-tightening the screw and replace the calibration window cover.