Pansonic Customer Service - A Camera Odyssey

I repeat, it's a lens shading issue.

The method by which images are produced--the interaction between objects in real space, the illumination, and the camera--frequently leads to situations where the image exhibits significant shading across the field-of-view. In some cases the image might be bright in the center and decrease in brightness as one goes to the edge of the field-of-view. In other cases the image might be darker on the left side and lighter on the right side. The shading might be caused by non-uniform illumination, non-uniform camera sensitivity, or even dirt and dust on glass (lens) surfaces. In general this shading effect is undesirable. Eliminating it is frequently necessary for subsequent processing and especially when image analysis or image understanding is the final goal.
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-- http://www.ph.tn.tudelft.nl/Courses/FIP/noframes/fip-Shading-2.html

Perhaps more appropriately, here's a doc from P&S Technik:
http://www.pstechnik.de/en/downloads/54_PRO35_Adjustment of the color shading.pdf
Color shading is a gradual shift of color from top to bottom in the video image due to a mismatch of the lens system and the electronic adjustment of the camera. Typically a green tinge is clearly visible near the lower edge and a red tinge near the top edge.​
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First question would be -- is there *anything* in front of your lens -- any filters, etc? If so, get rid of 'em. Second, is your lens spotless & sparkly clean? If not, get it so. Then try your shot again.

If you're still receiving an uneven cast, try white balancing and black balancing -- not that I expect it to help, but hey, it's free and quick.

If nothing else works, make sure you tell the engineer that the lens shading is off, and it's off on all three cameras in different ways, and show him the pics. Also, specify clearly what focal length you were using. And try it at different focal lengths -- I'd be somewhat surprised if you got the exact same shading characteristics at full telephoto and also at full wide angle...
 
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Luis, whereas your footage from your HVX is totally unacceptable, I also would like to point out that the examples you used (especially of the man in the white outfit) actually look really nice; as if you used some color in your lighting. Had you not mentioned that it was as a result of a faulty camera, I might of commended you on creative use of color.

Makes me want to check my HVX though, as this is worrisome...
 
Barry -

As usual it seems that you are spot on.
I should have mentioned all the excruciating details with the pics:

1) I took all filters (including UV filters) off the cameras.

2) I cleaned each lens before shooting

3) The stills you are seeing are at full wide. When at full telephoto I could only see a slight bit of color cast on my camera (because I was looking for it), and there was no apparent cast on the other two cameras.


EDITED TO ADD:
Also - All 3 cameras were white and black balanced at the same time under the same conditions.
 
vidled said:
Luis, whereas your footage from your HVX is totally unacceptable, I also would like to point out that the examples you used (especially of the man in the white outfit) actually look really nice; as if you used some color in your lighting. Had you not mentioned that it was as a result of a faulty camera, I might of commended you on creative use of color.

Makes me want to check my HVX though, as this is worrisome...
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Funny.
:)
Wish I could take credit for it.
 
Barry_Green said:
I repeat, it's a lens shading issue.
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Barry - is "Lens Shading" the same thing as "White Shading?"

The engineers originally told me that it sounded like a 'white shading' issue, but then ran their tests and came back telling me that they couldn't see any red cast on the footage they shot, so the camera was "fine" according them.

Just wondering if they were talking about the same thing you are.
 
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Yes it'd be white shading, and if they couldn't see it, they need to look again. Have you sent them the photos you shared with us, and they claim they're still not seeing it?
 
Thanks for the clarification - just wanted to make sure we were talking about the same thing.



I emailed them the first images before shipping the camera to them (sample with the chef in front of the backdrop).

Then, when I shipped the camera I included a DVD with stills, video clips, as well as screen captures showing the frames in FCP with the RGB Parade scopes (like the ones I posted).

They told me that they can clearly see the problem in the images I sent them, but they cannot get the camera to recreate the issue - so they see no problem with my camera, and concluded that it must have been a lighting and/or reflection issue. Their suggestion was that I use a matte box. Of course - that MIGHT (emphasize MIGHT) have made sense if we were only talking about 1 location - but I have examples from multiple locations with different lighting setups, etc - and they all exhibit the same red cast.

I emailed them the 3 way camera comparisson this morning, and I'm waiting to hear back from them. Called and left a voicemail letting them know I've emailed them samples - we'll see what they say.

As always - I'll keep you posted.
 
If you start a petition to replace your camera. I would like to be the first to sign. I have been following this thread and I hope it will end soon.
 
mcll said:
I just did a shoot on white and also found a color cast gradient that did not make
sense. Initially,I thought it was because of my white balance. But I was really careful
to make sure that I did it correctly. the light source was consistent (daylight) After reading this thread I now realize the problem is inherent in the camera somewhere.
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mcll - it just occurred to me that your samples could possibly be useful, even if it's just a single camera test - if you shoot your white backdrop and then flip the camera upside down (as ScrollLock suggested earlier) and shoot it again - then grab stills from each and post them for us to see.

In that scenario - even if your lighting was uneven or your color temps were mixed, the colors should stay with the backdrop...but if its the camera then they will follow the camera.

In fact - while we're at it - it would be great if everyone who can would try that test out and post your results here.

I shot at full wide, and exposed the image just below the 80% zebras (opening up the iris as much as I could before the zebras showed up.

Just make sure you do as Barry suggested:

1) Remove all filters from the lens
2) Clean your lens
3) White balance and Black balance the camera

Shoot at full wide and expose for 80% zebras.



I'm curious to see what we get.
(then again, everyones scene settings are going to be different....)
 
UPDATE -

Just spoke to the engineer at Panasonic.

He could clearly see that I had examples of 3 cameras that were all getting different color casts. I mentioned to him that the people I've spoken to (both on and off the board, including an engineer) have all told me that it seems to be a lens shading issue.

He explained the way they tested the camera for lens shading, and how they calibrated it - and that's when I thought to ask him (thanks to the comments made here) what focal length they do the tests at. He told me the camera was fully zoomed in when they tested it.

So - there's the culprit right there.

I explained to him that when I'm fully zoomed in the cast is virtually gone (on my camera its still slight, on the other two it is gone).

I further insisted with him that this was not a lighting issue - and that it was a constant occurance (he apparently thought this only was happeneing in certain lighting situations).

Long story short - he is passing my email and my pictures on to someone else that he feels may be able to offer some insight (I'm not going to post his name here, but apparently he's higher up). It seemed that it might be out of his element - which I don't fully understand as from what everyone has said, and everything I've read, it seems to be a clear cut problem with the lens shading on all 3 cameras (including the one Panasonic sent me as a loaner).

I will keep you updated as soon as I hear anything - I don't expect to hear anything else today.


By the way, if anyone in Austin is willing to lend their HVX for a test - I would love nothing more than to line up as many HVX's as possible and test them against eachother. I have 3 at the moment - I would love to set up 5 or 6 side by side and see what I get.

Of course, I don't know how much more evidence I need - but I'm starting to really wonder if this is a weird coincidence that I got 3 cameras with lens shading issues - or is this a pervasive problem with the HVX?
 
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Oh, I see where this is going. You get 10 or 12 people to send you HVX's, then you pick the one that has the cleanest white image. A little sanding on the serial number label, a little magic marker, and now "your" camera is fixed...Uh huh...
;)
 
danv said:
Oh, I see where this is going. You get 10 or 12 people to send you HVX's, then you pick the one that has the cleanest white image. A little sanding on the serial number label, a little magic marker, and now "your" camera is fixed...Uh huh...
;)
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I would never do that.

So...if anyone is interested in lending me their HVX, let me give you the P.O. BOX to ship it to....

:thumbsup:

Seriously - I would love to get a few more cameras in the mix if anyone is up for it.
 
I'd gladly join up with you if I were in town ...

This is definately an interesting / frustrating issue. Fix It In Post (Jerry) had my camera this weekend, and he tested it out, and it shows the same problems. I'll see if he has a pic or two he can share.

This is not good ......
 
Ryan E. Walters said:
I'd gladly join up with you if I were in town ...

This is definately an interesting / frustrating issue. Fix It In Post (Jerry) had my camera this weekend, and he tested it out, and it shows the same problems. I'll see if he has a pic or two he can share.

This is not good ......
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Wow.
Yeah, if you get some frame grabs of that, please post them in this thread.
 
Well, I didn't have time to do a detailed and highly controlled test, but here's the setup.

I threw a white sheet over a clothesline in the shade in the back yard. Evenly lit to 80% zebras. f5.6, the first in camera ND stage (didn't have time to control the light enough to not use the filter). White balance set to the 5600k preset.

Images can be found here: http://www.etchantdigital.com/pics/hvxtest

In the folder are the original .tif grabs (both wide and telephoto (telephoto is out of focus), flipped, and normal). JPG versions of all of the above, along with levels and saturation adjustment to bring out the problems. I've also included a PSD with all the layers in it, and adjustment layers with the filters I used for before and after comparison.

Hopefully Ryan will have time to do something more controlled than my on-the-run rudimentary testing.
 
Jerry - thanks for posting those.
Not sure what to make of those - as it seems like it was shot in less than ideal conditions -
The weird thing is, the cast that I"m seeing on that footage seems to be bluish.
All I've seen so far is red/green casting.
 
Definitely shot in less than ideal conditions. I just ran out and did it really quick because I was curious. I went back to some footage that I shot with the same camera using a Redrock M2 several weeks ago (shooting charts and such), in a much more controlled setup. The colour shifts were still evident, but not so extreme. Probably due in part to the longer focal length used to focus on the ground glass.
 
UPDATE -

WELL this is fascinating.
I apologize in advance if this is hard to read, but I'm refraining from using any Panasonic employees names.



So I get an email today from the engineer I spoke to yesterday - he tells me that since he may not be the expert on this topic he would like to refer me to the service engineer who could be of some help. The service engineer he mentioned is actually the FIRST engineer I spoke to, and the one who referred me to the guy who just sent this email. Bizarre.

But wait, it gets better.
The engineer he's referring me to is not the same guy he menitoned yesterday.
But he does tell me that he forwarded my email to the guy he mentioned yesterday and he did get a response from him. Of course, he then fails to mention what that response was. Incredibly efficient communication going on here.

But wait, the best is yet to come.
He closes the email by saying he's going to contact the service engineer and have him contact me... and the last line of the email is:

"One more thing [Service Engineer] is going on vacation starting tomorrow."


Of course - perfect timing.

So I've emailed them back - copied everyone of import on the email and asked that the service engineer call me today before leaving the office.

I've also asked him to forward me the response from the other engineer he contacted.


By the way - I should also mention that this guy I talked to yesterday - who was thrown my way as the real 'go to' guy to fix this problem - did not understand the term 'focal length' and also thought that maybe two 1K lights were not enough to light a white backdrop for the HVX to get a decent image. When I assurred him that two 1Ks is much more than adequate he told me that he didn't really know much about lights.

Now, I'm not here to slam anyone - but I do think these details are worth mentioning.
I mean - how can he be unfamiliar with 'focal length'?
Everytime I mentioned the term he 'corrected' me and said, "but you're talking about the zoom, right? Not the focus."


If anything I have been much too patient and much too nice with everyone involved.
If this service enginner doesn't call me today it looks like I'll simply find some other way to get this camera in working order, though I'm not sure if this is the sort of thing that can be fixed elsewhere.

I've dropped a line to Spec Comm to see if its something they can look at and fix in house - or if they would have to ship it to Panasonic.

Then again, at this point, seeing as I have 3 cameras here with different color casts on all of them - I'm not just wondering WHEN I can get my camera fixed - but IF I can get it fixed to my satisfaction. I can't help but feel that 3 cameras with the same issue in varying degree is a pretty big coincidence.


I'll keep you posted as soon as I hear back.


EDITED TO ADD:

I just remembered that I had the service engineers number from the first time I talked to him.
I just called him, he didn't answer - I left a voice mail telling him to call me back before the end of the day seeing as he was leaving tomrrow.
We'll see.
 
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UPDATE -

I was called by the first engineer within minutes of replying to his email.
Apparently the Service Engineer is gone for two weeks, and is already out the door.
Nothing much we can do about that - bad timing.

So - I asked him who else there was to talk to and he gave me the number to the Engineer he mentioned yesterday.
Apparently this is an engineer who mainly deals with the 'higher end' cameras (Varicam, etc).

I've since called and left him a voicemail - we'll see how this turns out.

In the meantime I suppose I should get back to work.
Though everytime I come across a shot where the red cast is apparent - it's like a knife in my eye.
:thumbsup:
(using a thumbsup in a vain effort to not tear out what is left of my hair)
 
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How close are the serial numbers of the 3 cameras you have? It's possible to get a bad run of components that affect a large number of units, and hopefully not an engineering design flaw.
 
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