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Auto Lighting Optimizer - Changes shutter speed in manual?


Hi, I have a question regarding ALO. I recently enabled it on my 1DX and have since noticed my shutter speed will automatically change slightly once in awhile (while shooting in manual with auto ISO.) For example: I set my shutter speed to1/60 and it will occassionally drop to 1/50 and then jump back to 1/60. I've checked the instructions but couldn't find anything regarding this. It only happens with ALO enabled.




Are you sure it's not your safety shift feature that is doing it and ALO is just by coincidence? I'd suggest disabling all safety shift and try again to eliminate this possibility.


By the way, you do know that ALO is applicable to jpeg and not to RAW unless you are using DPP?

Diverhank's photos on Flickr

Thanks for the reply. It's not being caused from safety shift as I'm not maxing out the ISO. Does safety shift not only apply to Tv and Av mode?

I do know it just applies to JPEG. I generally just shoot RAW, but I wanted to test out ALO. That's when I noticed the changing shutter speed. It's really not a problem to me as I won't really be using ALO, but I'm rather curious if this is normal or not.'re right no safety shift in M bad...

I have no clue...I don't use ALO.  I don't have the 1DX but on my 5DIII in M mode, I could've sworn I've seen the shutter speed flutter a few times...that's why I was so sure it was the safety shift feature...I only confirmed today that there's not supposed to be a safety shift in M.


I'll have to watch for this might be something else because I don't use ALO.

Diverhank's photos on Flickr