John P Mulgrew wrote:
I've seen posts about FoCal and might give it a try, thank you.
I also hesitated to purchase this program first, but IMO it is worth the initial cost especially if you have several Canon lenses. This program resulted in different MFA numbers which I got previously when I used the otherwise described ruler or screen methods. The FocalPro numbers turned out to be a lot more reliable and the method itself works quickly.
I wish Canon would automatically provide you with a such kind of calibration program when buying an expensive DSLR camera.
I will give it a try, 50L is the only lens I have issues with but if I can get that lens working properly then it will be worth it, just a shame that I need to adjust an expensive lens like this to get the damn thing to work.
Focal is a great program and judging by your comments that you can get it spot on in lv and MF then it's simply a af calibration issue not the lens itself. That being said all focal does it get your hit rate higher in af (you'll still have some misses especially at 1.2) the best way to improve results at large apertures is lv, MF, on a tripod, and if close to mfd a cable release as well. Additionally the 50L isn't exactly known for corner to corner sharpness nor is it known for great sharpness at smaller apertures (by about f2.8 its hard to see any difference between it and its two cheaper cousins).
Focal is a great program and judging by your comments that you can get it spot on in lv and MF then it's simply a af calibration issue not the lens itself. That being said all focal does it get your hit rate higher in af (you'll still have some misses especially at 1.2) the best way to improve results at large apertures is lv, MF, on a tripod, and if close to mfd a cable release as well. Additionally the 50L isn't exactly known for corner to corner sharpness nor is it known for great sharpness at smaller apertures (by about f2.8 its hard to see any difference between it and its two cheaper cousins).
robbymack wrote:
Additionally the 50L isn't exactly known for corner to corner sharpness nor is it known for great sharpness at smaller apertures (by about f2.8 its hard to see any difference between it and its two cheaper cousins).
Fast lens projects almost an "U" sharpe focal plane at large aperture so anything behind or in front of the curvy plan will be OOF; However, anything belongs to final "U" curvy focal plane will be pin sharp just like the center one. Here are some [email protected] border & center shapness samples:
Good samples above and a great demonstration of what it really means to bend light. As instructional as those are I don't think the average shooter is looking for only u shaped subject matter all the time for his/her 50L. It's good to know the (relative) limitations on the gear you have so expectations are set accordingly.
Absolutely send it to Canon. I had the same problem, even after MFA with FocalPro. When it came back from Canon, it was perfect.
Note that if you're trying to compare sharpness wide open with lenses like the 35L and 85L, you're going to be disappointed. The 50L isn't as sharp wide open.
Yeah I know it isn't as sharp wide open. I have the 35L as well and no issues with that. About how much is it to send it in and have canon calibrate it?
chrislambeth wrote:
Yeah I know it isn't as sharp wide open. I have the 35L as well and no issues with that. About how much is it to send it in and have canon calibrate it?
It's free if your camera body and lens are both under warranty. (Other than your cost to ship it in, of course.)
robbymack wrote:
Good samples above and a great demonstration of what it really means to bend light. As instructional as those are I don't think the average shooter is looking for only u shaped subject matter all the time for his/her 50L. It's good to know the (relative) limitations on the gear you have so expectations are set accordingly.
The final curvy focal plan sometime throw off the lesser AF firmware bodies since the border sensor reading was not strong enough compared to the center sensor. A better AF firmware body has more line of code to offset this differences from all AF sensors. A lesser AF bodies' sensor(s) calibration must be done to hande these cases.
badlydrawnboy wrote:
The 50L isn't as sharp wide open.
Don't trust 5D2 or lesser AF bodies. Use focusing screen to adjust the focal plan after AFed to get the best out of 50L. Here is a sample of 50L at 1.2 when i got it right...you can see...it is not the 50L optical sharpness issue but how we (AF) get the right 1/3 dof focal plan...look at the bamboo trees at the left corner for the "U" shape sharpness effects.
Another word, if you don't get sharp image from 50L then 99% of your body AF false but not 50L false. Lesser AF firmware bodies with off center AF sensor(s) expected to be choked when "U" light shape was bend to the max and 50L is one best light bender
Mine is sharp almost every shot just like 35L and 85L when used correctly. Use speedlight AF assisted (day and night) option to help AF sensor(s) and AF firmware while shooting 50L. Otherwise, install best focusing screen VF for any off center critical focus.
badlydrawnboy wrote:
It's free if your camera body and lens are both under warranty. (Other than your cost to ship it in, of course.)
+1, Chris. Send both cam and 50L lens in for AF calibration if needed
AF trouble shooting:
1. LV manual focus should be pin sharp if not then either the lens optical elements is off or the body EF mount position is off or image sensor position is off. Send both Cam and Lens in for calibration
2. Use AFMA process to AF to obtain LV best sharpness from step 1. If AFMA offset number is greater than +/-4 send the lens in for calibration. This step is very important to avoid final focal plane (1/3 dof ) issue while your subject distance or aperture changing.
3. VF should be in focus at AF confirmation beep while LV was in best focus; otherwise, MF focusing screen won’t help you. Send the body only to install focusing screen and VF calibration.
4. A healthy mechanical AF/MF system should have all of above three items. This step is required before any AF sensor(s) & lens firmware calibration.
mttran wrote:
+1, Chris. Send both cam and 50L lens in for AF calibration if needed
AF trouble shooting:
1. LV manual focus should be pin sharp if not then either the lens optical elements is off or the body EF mount position is off or image sensor position is off. Send both Cam and Lens in for calibration
2. Use AFMA process to AF to obtain LV best sharpness from step 1. If AFMA offset number is greater than +/-4 send the lens in for calibration. This step is very important to avoid final focal plane (1/3 dof ) issue while your subject distance or aperture changing.
3. VF should be in focus at AF confirmation beep while LV was in best focus; otherwise, MF focusing screen won’t help you. Send the body only to install focusing screen and VF calibration.
4. A healthy mechanical AF/MF system should have all of above three items. This step is required before any AF sensor(s) & lens firmware calibration. ...Show more →
Suppose all his other lenses are tack sharp with no OOF problems. Wouldn't that means it's a lens problem and not a camera problem?
Tom K. wrote:
Suppose all his other lenses are tack sharp with no OOF problems. Wouldn't that means it's a lens problem and not a camera problem?
Tom, AF firmware pre-set routines to be triggered to compensate any AF sensor(s) reading. AF sensor(s) see different projection signatures from different lenses at different aperture. I don't believe Canon passed all these AF calibration test to all available lenses before shipping them out.
Yes, it still be considered the lens firmware and/or body AF firmware issue and/or AF sensor(s) reading issue in this case.
chrislambeth wrote:
All other lenses are tack sharp. Even another 50L is. Mines not.
So your body works well with another 50L but not the one you have now? I would send only the lens in if the same lens does not work with another body; otherwise, sent both in.
chrislambeth wrote:
Yeah I know it isn't as sharp wide open. I have the 35L as well and no issues with that. About how much is it to send it in and have canon calibrate it?
I'm CPS Gold and ended up paying around $240 for the fix. Steep, but it went from being a barely used lens to my most used lens, so in the end it was worth it.
1. LV manual focus should be pin sharp if not then either the lens optical elements is off or the body EF mount position is off or image sensor position is off. Send both Cam and Lens in for calibration
2. Use AFMA process to AF to obtain LV best sharpness from step 1. If AFMA offset number is greater than +/-4 send the lens in for calibration. This step is very important to avoid final focal plane (1/3 dof ) issue while your subject distance or aperture changing.
3. VF should be in focus at AF confirmation beep while LV was in best focus; otherwise, MF focusing screen won’t help you. Send the body only to install focusing screen and VF calibration.
4. A healthy mechanical AF/MF system should have all of above three items. This step is required before any AF sensor(s) & lens firmware calibration.
but how to deal with backfocus at short distances?
is there a solution?
thnx
