Excessive GH1 FPN?

PJF said:
Are you saying you are concerned because you left the sensor physically exposed (body cap off) for 10 hours, or because you left the sensor exposed to light (lens cap off) for 10 hours? I presume it's the former.
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I'd like to know that, too. did you leave the gh1 without cap without lens? and was the room dark?
 
Try another 5 hours with the cap off. It might eliminate the issue completely. There's no reason why it will fry the camera, as long as the light is not mega-intense. I might do this myself - I get some banding in extremely low light and high iso.
 
PJF said:
Are you saying you are concerned because you left the sensor physically exposed (body cap off) for 10 hours, or because you left the sensor exposed to light (lens cap off) for 10 hours? I presume it's the former.

This test is very encouraging. It did cross my mind that burning a sensor in with light might be more productive than leaving it in the dark. It fitted in with user reports of GH1s improving with time.

I thank you for this test, and so do the family of silverfish who are enjoying their new home and currently tunneling a new access through that large flat plate with the pretty, multi-coloured surface.
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Indeed I was concerned leaving the sensor exposed I did it with no lense, pointing at a white sheet of card in a reasonably lit room over night. The risk is getting something on the sensor (bloody silverfish!) also leaving the gh1 on at 72 hours straight is pushing it (although day 2 started to get hot but day 3 was a lot cooler).
I decided to try it with cap off as I could see small areas of the band becoming more transparent but process was slowww so Id thought maybe more light would speed things along.

Problem with the test is I cant even guarantee it'll work for everybody (some have tried burn in and had nothing some others have tried it and had great results) and I cant really explain why one will and one wont.
Even doing this drastic bare sensor attempt didnt completely remove all of it.
But at least its shown a example of something happening.
 
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Ian-T said:
Well...I'll be a monkey's uncle..!! That's the first time I've seen a before and after and...YES....something definitely changed. There was a particular vertical band that I kept my eyes on till the end...and by the time 72hrs was notated it was barely there. I think leaving the cap off in the light actually did the trick.
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Yeah that vertical band was really bad...there was a smaller one on the left side also that started to go after 24hours which made me carry the test on.
Theres still a bit of right side of that band which is more noticable at 1600 iso but in comparison to the way it was...really noticable all over even at 400 iso...I can say its improved.
 
I think 10 hours will sort it good and proper, from your test. Hang it from a thread if you're worried about crawling insects getting on there, or cling film it (I think Americans call it saran wrap).
 
Well - i have always been super sceptical of this. But it doesn't pay to be too concrete in your thinking... and your test does seem to be reasonably well carried out.

I will eat my words and give it a go... though... why on earth would it work better with a lens removed than with it on? Is there a rational for that? Surely you could just do it with the kit lens on?
 
the doc said:
I will eat my words and give it a go... though... why on earth would it work better with a lens removed than with it on? Is there a rational for that? Surely you could just do it with the kit lens on?
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I suspect, it is UV light, that is the cause. It is filtered(to some extent) by the lens' optics. Pretty much every glass to some extent works as UV filter.
 
Am doubting the UV notion considering the arrangement mimirsan used.

Having the lens removed does ensure the whole sensor gets exposed and evenly so (assuming some effort is made to have a diffuse target, as mimirsan did).

I'll try this today or tomorrow with some thin paper taped over the orifice.
 
6 minutes ago my bare burn in test started.

I taped a saran wrap around the camera so that nothing can come onto the sensor.
The camera is looking towards a white piece of paper, distance ~15cm.
the room is lit by two little spots.
set the iso to 1600, its far overexposed (going out of the scale).

should i dim the light?
 
I find this whole "burn in" procedure one of the most bizarre things I've ever read...I think it's just typical internet forum induced paranoid. :D

If anyone needs their camera's sensor "burned in"...just send it to me. I'll take it out and actually shoot something with it! Both of my GH1 sensors are "well done" already.

For goodness sake...it's a camera...not a pair of Doc Martens! ;)

I'm not saying it won't work, just be sure to wrap some Reynold's Aluminum Foil around your head as well, to keep the government from beaming FPN directly onto your optic nerve.
 
I used to think that too, after letting the camera switched on for the whole night with lens cap on with no visible change.
but after the great results mirmirsan has posted after letting the sensor burn in with light for 10 hours, i think I'll give it a try. I have nothing to lose, you know?
i will post my results the other day.
 
Hi guys thanks for looking at the test!
Again though I must stress I cant guarantee what results you may have to be honest I was suprised myself with the result but some have tried all kinds of burn in tricks with no luck hence why I said its probably better to go out shooting as much as you can...Im in agreement with swyzlstyx to a certain extent....its a camera...a bloody good one.

Saying that it would be interesting if we see more results to bring a clear up doubt to the "burn in trick" otherwise Im in the minority few who "claim" its worked.
 
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@ faultiersid
Not sure ...I just thought "bugger it" due to impatience and took the cap off.... I had one overhead light on in a backroom and the white card was around 10cm away...the image on the lcd screen looked consistant edge to edge with no shadows etc.
 
I wonder it could be some noise reduction or pixel remapping routine that is slowly learning and kicking in. Though I have experienced burn in many times with electronics before, even measurable by oscilloscope
 
Dazza said:
I wonder it could be some noise reduction or pixel remapping routine that is slowly learning and kicking in.
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yeah, heard that before. but during the burn in, there is no fpn at the screen. either it's pure black (lens cap on) where (at least my) gh1 shows no stripes, or it's pure white.

i got fpn in bright-colored areas (white, grey) which are underexposed about 1.5-2 steps. at every iso, 100, 160, 320...
for me, iso 1600 looks often (almost always) better than 640 or 800 because the increasing exposure erases the vertical stripes.
noise is not such a big problem, even at 1600. (ymmv)


@mimirsan:

what did your friend say to the new burned in gh1 performance? I'm still interested if this can be more pushed by another 5-10 hours.
 
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I've started my "typical internet forum induced paranoid" and will let it run overnight and tomorrow-work-hours to see what happens. I'm a natural pessimist so have no great expectations; it either won't work or it'll work brilliantly but catch fire and burn my house down before I get the chance to see the best GH13 in the world, evah.
 
so, after 14 hours of burn in....


no change. not at all. pixelpeeper would say it's even worse than before, but mostly equal.


cam was set to mjpeg mode during burn in, if thats important to any1
 
I finally got my GH1 in my hands today. I haven't hacked it yet because I don't have a fast card, but even without it I wanted to see how "bad" the fpn is. I see very little to almost none at 800iso and at 1600iso if it is underexposed, then in certain areas - like in a recessed white wall, but not on the white wall in front. I don't think it is as bad as Matthew's GH1 which is the same serial.

Slight banding at 1600iso at lower right corner.
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So my questions - is this acceptable at 1600iso and to people who believe they have a "good enough" GH1 without excessive banding, what is the highest iso you use? Is it 1250iso, or is there anybody going into 1600iso?

I've seen this video where the shooter says he used 1600iso in some places, but not sure where and if the conditions were too perfect where banding wasn't going to rear it's ugly head.
 
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