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-   -   PMW-350K Back Focus Problem Solved (https://www.dvinfo.net/forum/sony-xdcam-ex-pro-handhelds/503850-pmw-350k-back-focus-problem-solved.html)

Patrick McLoad December 25th, 2011 10:51 AM

PMW-350K Back Focus Problem Solved
 
Just a heads up to all of you with a Sony PMW-350K and similar cameras. I was having a problem with the back focus completing its electronic setting (end result showed "NG: Timed Out"), and, the auto-iris was sluggish. I sent the camera to Sony Service Center in New Jersey and in short, the problem was because in the OPERATION menu, I had "CLIP HIGH LIGHT" turn ON. Going through the back focus procedure will NOT over-ride this setting!

So if you ever have this problem, be certain the the above setting is turned OFF....and keep it turned off!!

Patrick McLoad

Luc De Wandel December 25th, 2011 04:40 PM

Re: PMW-350K Back Focus Problem Solved
 
Very useful information for all those who use the kit lens. Thanks.

For those like me, who didn't want the kit lens because of its electronic, awkward manual focusing, it's a confirmation that adjusting the flange back setting can best be done manually on a 'normal' lens. It's a simple procedure that - as far as I'm concerned - doesn't ask for automation.

Patrick McLoad December 25th, 2011 05:05 PM

Re: PMW-350K Back Focus Problem Solved
 
I agree with that assesment of the kit lens, but Sony made it impossible (cost wise) to buy the body only. I had always used Canon lenses, and always had access to manual adjustment of the back focus, which is extremely needed when slapping on a wide-angle adapter. You can't do that with this electronic lens. Someone told me that Fuji was gonna make a kit for manual adjustment for this kit lens, but I'm not holding my breath.

But the auto-focus is nice for run 'n gun shooting.

Patrick

Mike Marriage December 26th, 2011 05:41 AM

Re: PMW-350K Back Focus Problem Solved
 
Luc, remember that the kit lens focuses in a different way to conventional ENG zooms. As I understand it it uses elements towards the rear of the lens, moved by servos. The focus is calculated in camera and I presume that the back focus process is actually a calibration process for these calculations rather than moving an element into a fixed position. (Feel free to correct me if I'm wrong).

The up side of this design is an exceptional optical performance for the price point and no breathing.

Luc De Wandel December 26th, 2011 08:14 AM

Re: PMW-350K Back Focus Problem Solved
 
No, I think you're completely right, and I've seen results of the kit lens that prove it's good quality-price relationship. Very sharp indeed and no breathing. But I'm so unconfortable with the 'feel' of the focusing ring on lenses like these, that I would never use one, even with all it's advantages. I'm quite sure it works well on auto focus, but then again I hate autofocus for a videocamera...

Mike Marriage December 26th, 2011 08:49 AM

Re: PMW-350K Back Focus Problem Solved
 
I also dislike most servo focus but it is pretty good on the 350K kit lens. The build and feel of the lens isn't quite as nice as high end ENG lenses but it is perfectly functional. In everyday use it feels like a mechanical connection, with end stops, focus scales and nice resistance. There is also no noticeable lag unless you do a crash zoom which requires 1 frame to catch up. However the zoom itself is so jarring that focus lag isn't really noticeable unless you frame-by-frame the footage.

I've never used the autofocus so can't comment on that however it's very handy to be able to switch to macro mode by simply clicking the focus ring forward, disengaging the focus marks.

Jim Forrest December 29th, 2011 10:19 AM

Re: PMW-350K Back Focus Problem Solved
 
@Mike

Enjoyed your 'Camera Movement' article.

Mike Marriage December 29th, 2011 12:13 PM

Re: PMW-350K Back Focus Problem Solved
 
Quote:

Originally Posted by Jim Forrest (Post 1706280)
@Mike

Enjoyed your 'Camera Movement' article.

Thanks Jim, haha, forgot that was on my site, glad it was of interest!

Andy Taplin January 1st, 2012 09:17 AM

Re: PMW-350K Back Focus Problem Solved
 
Thanks for the tip Patrick

I had real problems with my first Fuji kit lens getting the BF to function - could be I had the clip highlight on, can't be sure now. And then I had the whole lens go down (no focus control) on a shoot in Paris - very embarrassing!

Sony at first said there was nothing wrong with it as the fault was annoyingly intermittent. Eventually I got a new one from Sony, but only after getting my excellent dealer Prokit in the UK involved who confirmed the fault.

My assessment of the kit lens is that it is very sharp (especially edge to edge) at a bargain price and of course suits the camera perfectly - but there is a big question mark in my mind over long-term reliability. I've had no further problems a year down the road but we'll have to see.

Jim Nogueira October 21st, 2015 09:11 AM

Re: PMW-350K Back Focus Problem Solved
 
I know that this is an old topic, but this may be helpful to someone. I was getting frustrated trying to do a flange adjustment on my PMW-300 (and getting the "NG" message) when it occurred to me to try it with the UV lens protector removed. Problem solved.


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