Trouble with SpyderLensCAL (Page 2): For the wider lens settings (24mm) - did you change the distance to the target? It should be about 1/3 of the distance for 70mm. If the target is...

ChristianHJensen

abc1234 wrote:

I am going to try to answer all remaining question... (show quote)

For the wider lens settings (24mm) - did you change the distance to the target? It should be about 1/3 of the distance for 70mm. If the target is too far away you might have the focal point including the ruler and the background thus not a definite distance the AF is trying to focus on. Also - you need to have the light on the target (to make sure the af system has enough light) and some on the ruler to be able to ascertain the point of focus)

TriX Loc: Raleigh, NC

abc1234 wrote:

I am going to try to answer all remaining question... (show quote)

Good luck. I’ve found FoCal to be an excellent product - I hope you do as well. Since it plots resolution as a numerical value (vs correction), I’ve found it’s useful for evaluating the ultimate sharpness of a (new) lens as well by eliminating all the subjective variables. Values in the 1200- 1300 range indicate a sharp, high res, properly corrected lens, while values in the 1000-1100 range or lower are less desirable or require correction.

CO

TriX wrote:

Good luck. I’ve found FoCal to be an excellent product - I hope you do as well. Since it plots resolution as a numerical value (vs correction), I’ve found it’s useful for evaluating the ultimate sharpness of a (new) lens as well by eliminating all the subjective variables. Values in the 1200- 1300 range indicate a sharp, high res, properly corrected lens, while values in the 1000-1100 range or lower are less desirable or require correction.

I'm going to have to look into FoCal next. It's no doubt the most sophisticated system for AF fine tuning. I read somewhere that it will also find the aperture where the lens is its sharpest.