Focus Drift in Auto/Manual Focus Mode
 

Doing some rack focus things today. I usually use full Manual focus mode but I needed to use the macro mode, the closest thing was pretty close (it was a flower in a field of flowers).

I had the EX1 in the Auto-Manual Mode (focus ring pushed forward), which I've found is pretty smooth, almost as smooth as the manual mode.

Anyway, I focused into the distance, using the peaking to ensure I was actually focused out there, probably 150 feet away.

When I stopped turning the focus ring, I noticed that gradually the focus would shift back down to a middle distance, like maybe 50 feet. I could tell because the peaking shifted down to that point. Also the focus distance indicator bar was shifting.

OK, I thought, the auto focus switch is on, but it wasn't. I played around a bit more with it but didn't have time to completely figure out what was wrong.

From what I know though, if the Auto focus switch is off, there shouldn't be any auto focus going on or any drift. I don't think I had depressed the auto focus button at any time.

Any hints?

ive had this too - I found if I turned the steady shot stabalizer off it cured the problem - i figured it was some how interfering with the focus when on a tripod

Matt you are correct Image Stabilizer off when on tripod or your focus will shift I have notice this also. But use full manual when ever you can.

Isn't this the "focus assist" which helps you "in detail" for better manual focusing?
You can switch it off in menu. For me this works fine now...

I have always kept Focus Assist off so I don't know it issues.

Focus Assist is causing the problem.
It's one of the issues I explain in my new EX1 and EX3 field guide books.

Vortex Media's XDCAM Field Guides

Nice job Doug it looks like a must for everyone to have in the kit bag.

Just ordered one Doug, the DVD is great! The book will be nice as well.

Doug,

Looks very nice! Do you cover much under the Picture Profiles section? I'd love to learn more about this.

Paul, Jason, Ted,

Thanks for the feedback. I'm glad you like the idea of the Field Guides.
It's a project I've been thinking about since last summer, but just now had the time this winter to actually get it done. If I had known how much time and money it was going to take I'm not sure I would have done it, but it's hard to quit when you're half-way.

I do spend a few pages explaining my philosophy on what Pictures Profiles are intended for and how/when they should be used, but I do not get into the nitty gritty of explaing all the parameters. As I say in the book, I could spend 500 pages on Picture Profiles and it would be a waste of time. That is my opinion, and I know very well that not everyone would agree with that statement. That's fine. Everyone has a different take on Picture Profiles.

I do share my personal Picture Profile settings and then teach the step-by-step instructions for how to make the changes.

But, the bottom line is, if you are looking for a detailed explanation of gamma, knee, etc. this ain't it. I do provide a link where you can download a 75 page PDF file called "Sony Camera Technology Basics" and a lot of that information is in there if you like technical details.

Great idea Doug. I just ordered one.
I've watched your DVD several times, but my retention is not always what it should be. This will be great reinforcement as well as something to toss in the camera bag for on the spot questions.

I didn't know you had field guides available! I LOVE YOU MAN! I have your DVD and found it invaluable. I'll be ordering a field guide.