EX-1 Backfocus Status

E

EX1USER

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I purchased a EX1 about a week ago. After noticing on a few paid shoots that some wide shots were looking soft I checked my backfocus on a Seimens star chart and low and behold my camera with the ND filters on, backfocuses extremely bad.

B&H said they don't know about the problem and Sony's support line isn't telling me much more than there is a memo.

Is the problem fixed with newer serial numbers? Should I swap out for a newer one, or send my unit in to get repaired?
 
The backfocus problem is a known issue on EX1s, and Sony has been trying to fix them with varying degrees of success and failure.

If you have the chance to swap for a new one you should, obviously.
 
Here's an article from Adam Wilt about the EX1 backfocus problem. Basically, he says that if the backfocus calibration was done without the ND filter, then it should work without the ND filter. Likewise, if the calibration was done with the ND filter, then you'll have no trouble if you use the ND filter all the time. But if you switch modes, that's when you'll have problems with backfocus.

http://provideocoalition.com/index.php/awilt/story/ex1_misfocusing_explained/

I don't think Sony has a solution yet, so there's really no use switching cameras. But keep an eye out before your warranty runs out.
 
I just had mine repaired by Sony - which meant a firmware upgrade (v1.05) had to be done by the factory. It fixed my problem.
 
I'm hoping a statement from Sony will be released to explain what software version v1.05 entails.

Adam Wilt mentions the BF calibration only seems to work at a set ND position, or off.

Apparently not all the EX1 cameras have this issue. My camera does not appear to have this issue, and yes I'm viewing the footage on a large screen, not the onboard LCD.

It makes me wonder if the new software is accommodating a great BF range that might be different from camera to camera.
 
Will someone explain or put a link in how I would go about testing this back focus problem?
 
kubalsky said:
There is also another thread here or somewhere where someone explains how to check if your camera has a problem. Ill post when I find it again.
Click to expand...


http://dvinfo.net/conf/showthread.php?t=117307

You really have to look at this carefully. My buddy tested it and thought his camera was fine then asked me to double check. it was off. The trick is when putting in the ND, focus on a distant object like trees or something, then when you go wide see if it gets sharper when you roll the focus back to 3' or so. Obviously it should not.

Lenny Levy
 
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ex 1 card failure

ex 1 card failure

i have purchased an ex1 and have known that there could be a back focus problem , regardless the camra feels too good to be true but my experience first up was that my card corrupted and i lost my days shoot . this is new camera , new card , i was deleting every bad take , last clip delete , loaded half card to mac before continuing on
and then all of a sudden message came up no ? media remove card , computer did not recognise card , abd i lost all days work apart from partial save we did to my mac , what happened , did partial save partition card , did delete last clip exceed clip limit for sxs card . whatever happened without warning i lost everything and my initial exitement with all the cool features was shattered , i have not been a fan of "little" camerasbut this one is one out of the bag / but hopefully this glitch will not repeat , did we have a systematic error in deleting last clip . as this error messageis said to occur if you exceed clip limit per card , although we deleted clip does the clip count still remain , what is the clip limit
 
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Fixed!

Fixed!

Today I fixed the backfocus problem for myself, just before I wanted to return my EX1 for another exchange.
I did the FB-adjustment procedure once again - but this time I used 12 backfocus charts side by side (actually 4 columns and 3 rows), which I attached to a white wall of my house.
I did the procedure for each ND - setting separately. Looks like only 1 backfocus chart was not enough to fix my problem. The camera was 3m away from the charts - aperture of course wide open.

Maybe this trick will work for others as well.
The sad thing is that Sony could not fix it in 3 repair attempts.
I hope it will stay like this now.

My camera has the new FW 1.05.

Maybe this technique will help others as well.

regards,
Gerald
 
Gerald Loidl said:
The sad thing is that Sony could not fix it in 3 repair attempts.
Click to expand...

Maybe because you have the secret sauce that enables what the designers intended:

Gerald Loidl said:
Looks like only 1 backfocus chart was not enough to fix my problem. The camera was 3m away from the charts - aperture of course wide open.
Click to expand...

Here's my results - mouse-over to flip images.

A seasoned DoP can judge the little tiny spot in the middle of the screen to be significant, but to a rather small, dumb computer, finding focus charts in its sensor read-out would be more by smell than by recognition. If you see what I mean.

The engineer, realising that this lens is pushing the envelope and really should have a FB adjustment, but needing to hide it from people who would white-set without anything white in front of them, would probably say 'look for areas of white and black close together' in the software. The camera is looking at a teeny A4 focus chart taped to the side of a brick wall painted a bland shade of Magnolia. Now, are the shadows between the bricks a focus chart? Or is the little squashed spider in the middle anything significant?

Lots of charts = pure genius. A virtual beer to you, dear chap!
 
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Will someone be so kind as to walk me through the steps . . . I am trying to calibrate my ex-1 to determine whether or not it has a back focus issue.

It just arrived so I am trying to test it for vignetting and back focus issues before my return deadline.

I am going to print out the 12 charts mentioned above

What are the best settings (iris and shutter) for testing and calibrating

Any caveats?

No firmware updates (unless the cameras are now shipping with the new firmware).

I am hoping that someone who has successfully dealt with this issue can share your experience.
 
o.k. try at your own risk. Thats how it worked for me for 2 cameras Sony could not fix - your experience could be different..

Camera was set to 1080 25p
PP1 with detail off
I used 12 focus charts (Siemens Star) - I think a few less would not make a difference... 4 columns 3 rows
Camera was 3 meters away from a white wall outside my house
Aperture always f1.9 fully open at stop (use shutter to adjust brightness)
Focus full manual
Zoom servo on
Macro set to off

Set to ND off - zoom in fully - use expanded focus and sharpen
Use the maintenance menu - choose backfocus adjustment (FB)

When finished - leave menu - do not turn the camera off
Turn on ND1 - adjust brightness with shutter
zoom in fully - use expanded focus and sharpen
Use the maintenance menu - choose backfocus adjustment (FB)

When finished - leave menu - do not turn the camera off
Turn on ND2 - adjust brightness with shutter
zoom in fully - use expanded focus and sharpen
Use the maintenance menu - choose backfocus adjustment (FB)

no need to turn off the camera in-between adjustments.

Good luck - its pretty easy to perform - I hope this will solve your backfocus problems as well.
 
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