What Prime would you suggest?

ok, I'm sure this question has been asked a number of times, but I'm starting a new thread. I was having problems with my 85mm 1.8 on my 7D. I tried it on my daughter's camera canon T5 and on a canon 6D and it worked perfectly. I have a canon 7D and it just wont lock focus most of the time so this lens is not meant to be ...I bought it used. I love the look of the 135L lens so It was suggested the 85mm.

What are your suggestions for under $1000. I know most of you tried every lens on the market and you know which ones to keep away from and which ones you love. Any suggestions would be much appreciated. I would even buy a new canon 85mm 1.8 because when it did lock focus, it was beautiful.

if the 85 wasn't locking focus there was an issue with the lens, the camera or the operator.

Amazon..... (that is the prime I use)




That being said, I agree with Ed, there is something wrong that should be addressed. You don't want to use the 6D as it can focus in much lower light than the 7D and could give false impressions about any capability or lack of with the 7D, but I would run more tests side by side with the T5 perhaps? Same scene, etc...

Per your post it sounds like the problem is with the camera since the same lens focuses fine on two other bodies. Have you tried another lens on the 7D?

The issue is most likely with the camera body and/or the operator. If the lens operates appropriately on other camera bodies, then something is likely going on with your current camera body and it's settings and how your AF is setup, which is operator choices. I think we've been through all of your 85 & 7D MFA and AF issue threads and all. I know you've done some MFA with your 7D and the 85, but not really sure how accurate it was done.

Did you ever perform the dot tune MFA method?

Very best,

I agree that the problem is likely not the lens.

AFMA itself won't likely cause AF acquisition issues, it is a final step motor change at the end of the focusing function as a positional offset.

However, it is possible other AF changes or functions on the 7D might be causing issues perhaps, as you have pointed out. It might be best to do a complete factory reset on the 7D and start over?

cristphoto wrote in post #18536967
Per your post it sounds like the problem is with the camera since the same lens focuses fine on two other bodies. Have you tried another lens on the 7D?

I have a canon 70-200 f4 and Sigma 17-70 2.8 and they work great. I rarely if ever miss focus.

TeamSpeed wrote in post #18537187
AFMA itself won't likely cause AF acquisition issues, it is a final step motor change at the end of the focusing function as a positional offset.

However, it is possible other AF changes or functions on the 7D might be causing issues perhaps, as you have pointed out. It might be best to do a complete factory reset on the 7D and start over?

Good Idea

Got home last night, did a reset on my camera and took out the battery. Put the battery back in, tried the lens and it seems to be focusing perfectly and fast. I just played with it in the house (it is freezing out) so on the weekend, I'm going to try it outside. I hope this fixed the problem but now I'm stumped because my 2 other lenses were working perfectly...

It has been shown that sometimes a complete reset will fix random issues that pop up with AF. I don't believe we have ever figured it out, but that is the reason the suggestion to do a reset is given so many times. Just like Windows boxes, sometimes a reboot just fixes things inexplicably.

In other situations, even a reflash of the same firmware you have might fix issues. Again, this is inexplicable. My guess is that system level registry values and settings that the user cannot directly influence get corrupted, and a reset and/or firmware reflash resets all of that back, ie. there might be a memory leak in the Canon firmware code that corrupts AF tables, etc.

anitaw2 wrote in post #18537779
Got home last night, did a reset on my camera and took out the battery. Put the battery back in, tried the lens and it seems to be focusing perfectly and fast. I just played with it in the house (it is freezing out) so on the weekend, I'm going to try it outside. I hope this fixed the problem but now I'm stumped because my 2 other lenses were working perfectly...

Yes it is perplexing. Perhaps there was a micro-adjustment setting in the body for the suspect lens. But even that should just be a fine tuning adjustment at best - not enough to throw images out of focus. Glad to hear you have it solved.

Focus looks good to me. Looks like the reset worked.

Sometimes you can get some crud on the contacts, which causes problems. Taking the lens off and on will then wipe the crud off and everything works fine, leaving you scratching your head.