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Old December 14th, 2007, 11:44 AM   #1
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Vignette Problem DIY Fix using Back Focus Correction...?

I am working outside of the US right now and stopped by a Sony dealer as part of my worldwide search for extra EX1 batteries (I found them).

The dealer gave me an interesting tidbit of information that I thought I would share. I do not have my EX1 with me, so I can't try it myself, but I will upon my return.

That said, please try this at your own risk. It doesn't seem like something that could void a warranty or screw anything up too badly, but I really don't know.

The dealer said that if you adjust the backfocus of the camera, the vignetting problem goes away (this is the part I take with a grain of salt). I told him I did not know how to adjust the backfocus, and he gave me instructions to do so that he received from Sony. It involves going to the hidden maintenance menu - here are the instructions:

1) Press and hold the "CANCEL" "SEL/SET" and "MENU" buttons simultaneously. The back focus is the bottom item in the Maintenance menu.

2) Point the camera at a back focus chart with the camera about 12' away from the chart.

3) Zoom in and focus.

4) Select "Auto FB Adjust"

5) Select "Execute"

6) The camera will zoom in and out and do an Auto Back Focus correction.

(end of instructions)

I don't know which way the focus ring needs to be set (it may not matter) but it seems that zoom servo will need to be engaged in order for the camera to take control of the zoom.

Again, try at your own risk (other maintenance menu items may cause problems if you mess with them) but if you try it, tell us how it goes. I'll give it a go in a week or so when I am reunited with my camera.
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Old December 15th, 2007, 10:06 PM   #2
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OK Eric,

I bit the bullet and did the back focus correction.

It all went exactly as you had described.

Unfortunately it did not make any significant difference to the vignetting. There my be very slightly less, it is difficlut to tell exaclty but it is still there.

So Sony will need to come up with a different fix - or maybe thay can do this better than me.

Not good news.
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Old December 16th, 2007, 07:46 AM   #3
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Graeme,

Thanks for trying that. My skepticism was warranted. I'll still give it a go on Thursday when I have my camera again - maybe try some before and after pics just for the sake of science.

I am sure your backfocus is better for it nonetheless.
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Old December 16th, 2007, 10:06 AM   #4
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Graeme,
did you notice an improvement in backfocus?
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Old January 5th, 2008, 03:42 PM   #5
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I'm interested too: Greame, did you notice any improvement?
Has anyone else tried out this Back Focus Correction?
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Old January 5th, 2008, 03:44 PM   #6
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I just tried this and did notice an improvement in back focus.

Pretty painless process.

I have an (as yet) unrepaired vignetting camera and noticed something else, which I'll post in the vignetting thread - that the zoom does not track straight, making it obvious that the lens is mounted off-center.
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Old January 6th, 2008, 05:24 AM   #7
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Thanks, Eric!!

Eric, Thank you so much for your information. I fixed my backfocus problem with using your post and i'm quite happy.
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Old January 6th, 2008, 10:33 AM   #8
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when doing the adjustment, which position does the focus ring need to be in? Full Manual?< or does it matter ? >
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Old January 6th, 2008, 10:42 AM   #9
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I had mine in full manual when I did it and it worked fine.

It may well work either way - not sure.
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Old January 6th, 2008, 11:25 AM   #10
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Thanks Eric, I checked mine and its fine. Nice to know how to do if needed!
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Old January 6th, 2008, 11:40 AM   #11
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As a former facility engineer who had no problem doing the software maintenance routines and BetaSX and DigiBeta decks, I really wish Sony would make the service manuals available. BTW if you look at page 15 of the user manual it makes reference to the cover of the lens control clock and notes that it is "properly adjusted" at the factory. I have a hunch this is what they're accessing to fix the "properly adjusted" vignetting camera.

Some people are capable of doing service and some aren't. Some service only involves software routines and some involved hardware and test gear. Releasing the test procedures with a warning not to do this while the camera is under warranty might be good enough.

If "we" prefer Sony authorized service, we should at least have methods to check the work done.
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Old January 6th, 2008, 02:58 PM   #12
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Sorry guys,

I was late replying to this thread. Must have missed it over Xmas. I didn't see a back focus problem with the original camera that I tried it on - I was doing it to try and fix the vignetting issue - and you all know by now that it certainly didn't.
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Old March 17th, 2008, 01:47 PM   #13
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After having my cameras shipped back from a job I noticed a Back Focus problem. I went through the adjustment and it looks better then when it came new.

Thanks Eric
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Old March 17th, 2008, 04:29 PM   #14
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did not work for my backfocus problem.
It got better - but did not fix it completely.
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Old March 17th, 2008, 06:18 PM   #15
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Gerald that could also be the case with me it improved but not if it is perfect since I have not looked on a large monitor yet.
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