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03-30-2007, 12:00 AM   #1
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VPN...What Gives?

There have been many people on different forums expressing their concerns regarding VPN (Vertical Pattern Noise) in the Pentax K10D. Although I haven't experienced this anomaly, those who have done so feel that Pentax have not addressed these concerns. Can a Firmware Update resolve this issue? Is it exclusive to Pentax or does it come down to understanding the limits of the digital domain. I tend to believe that if ones exposure is correct within reason, that this issue does not crop up.

Ben


Last edited by benjikan; 03-30-2007 at 04:56 AM.
03-30-2007, 12:08 AM   #2
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Hi Ben,

There's not a big area of mid shadow in the below shot, but you can see the dark vertically streaked pattern in the noise in the out of focus blue hat at the bottom of the frame. I would consider this photo properly exposed. And, this is with a bit of NR - without it, it was worse. If the mid shadow region was bigger, and important to the photo, it would be more annoying.

I believe it can be fixed in firmware, but nobody knows anyone at Pentax that will cause Pentax to stop simply denying the issue, and eventually suggesting we buy the new K10D 2 coming out in summer/autumn that completely eliminates the problem. (Which I wouldn't be able to afford to do.)

Larry
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03-30-2007, 12:14 AM   #3
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Memo

I have specifically addressed this issue with Pentax, France and I am sure to receive a response to my query shortly.

Here is a copy of a memo I sent a couple of days ago.

Hello Amigo;

Will Pentax address the problem of VPN (Vertical Pattern Noise) in their next Firmware Update? Could you ask Hamburg if they are aware of this problem? I am sure they are as many people have voiced their concern. It generally occurs at higher iso use.

Best Wishes...

Benjamin Kanarek
03-30-2007, 12:23 AM   #4
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I cannot see any vertical streaking in the area you mention nor, indeed, anywhere else in the photo. If you say it is there then I'm sure it is but I cannot see it.

I use a monitor calibrated with a Colorvision Spyder. Perhaps it only shows up in the full size photo...?

03-30-2007, 02:24 AM   #5
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QuoteOriginally posted by benjikan Quote

Hello Amigo;

Will Pentax address the problem of VPN (Vertical Pattern Noise) in their next Firmware Update? Could you ask Hamburg if they are aware of this problem? I am sure they are as many people have voiced their concern. It generally occurs at higher iso use.

Best Wishes...

Benjamin Kanarek
That's a powerful email directly to the point. If they need samples of properly exposed shots showing it, that will be easy. - let me know.

Please tell us their response when it comes in.

Larry
03-30-2007, 02:30 AM   #6
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QuoteOriginally posted by chrisman Quote
I cannot see any vertical streaking in the area you mention nor, indeed, anywhere else in the photo. If you say it is there then I'm sure it is but I cannot see it.

I use a monitor calibrated with a Colorvision Spyder. Perhaps it only shows up in the full size photo...?
It's tough to verbalize, but you can see one dark vertical line/pattern starting at the left wisp of hair "touching" the hat, and another to the right, and also broken parts of "stripes" on either side.

It is minimized a bit due to a little NR (I tried not to get too smeary). I didn't intend to show this pic as it pushes the SR to my limits - 300mm f5.6 1/20 sec. ISO 1600

Larry
03-30-2007, 04:33 AM   #7
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Thanks for asking Pentax about it. I'm looking forward to hearing their reply.

I see it in a very small percentage of my pictures (< 1%), usually in high dynamic range scenes. It comes up in high iso night photos where there's a lot of dark areas, or when I expose for the highlights and try to boost the shadows later in post processing. I don't really find it a major problem for the type of shooting I currently do (I rarely use high iso), but I can see how it could be a major issue for some.

I don't know if they can fix it in firmware, but if they can, it would be nice to have the extra usable shadow detail. If Pentax needs more examples, I'm sure the users here could provide some.

Last edited by walter; 03-30-2007 at 04:52 AM.
03-30-2007, 05:02 AM   #8
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VPN

QuoteOriginally posted by walter Quote
Thanks for asking Pentax about it. I'm looking forward to hearing their reply.

I see it in a very small percentage of my pictures (< 1%), usually in high dynamic range scenes. It comes up in high iso night photos where there's a lot of dark areas, or when I expose for the highlights and try to boost the shadows later in post processing. I don't really find it a major problem for the type of shooting I currently do (I rarely use high iso), but I can see how it could be a major issue for some.

I don't know if they can fix it in firmware, but if they can, it would be nice to have the extra usable shadow detail. If Pentax needs more examples, I'm sure the users here could provide some.
As I expressed in my original post, I have not experienced this anomaly and if I did, I would be making a HUGE stink about it. However, I sent the above memo to Pentax for those who have expressed their concerns regarding this problem. This is the best I can do under the circumstances. I do know, that most large companies adjust their R&D based on feedback from actual users.

Best Wishes
Ben

03-30-2007, 05:24 AM   #9
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QuoteOriginally posted by benjikan Quote
As I expressed in my original post, I have not experienced this anomaly and if I did, I would be making a HUGE stink about it. However, I sent the above memo to Pentax for those who have expressed their concerns regarding this problem. This is the best I can do under the circumstances. I do know, that most large companies adjust their R&D based on feedback from actual users.

Best Wishes
Ben
The best (i.e. most constructive) post on this issue is here:
GordonBGood's VPN Thread

You undoubtedly have VPN on your camera as described above, but in proper lighting and without pushing the exposure, it is barely noticeable.

Unfortunately, some formerly well-respected contributors 'over there' have taken to shouting down any discussion about VPN, so I am doubtful that there has been much meaningful discussion about it lately.

Last edited by carpents; 03-30-2007 at 06:10 AM.
03-30-2007, 06:01 AM   #10
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QuoteOriginally posted by carpents Quote
The best (i.e. most contstructive) post on this issue is here:
GordonBGood's VPN Thread

, so I am doubtful that there has been much meaningful discussion about it lately.
I vote this phrase for the " understatement of the year" award
03-30-2007, 06:25 AM   #11
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This is about as bad as I've experienced VPN. In the shadows , upper left. Given the conditions, I think it is not bad at all. There is a bit of random noise in the tires, but I only see it at 100% crop.

Pentax K10D ,Pentax smc P-FA 77mm f/1.8 Limited 1/180s f/6.3 at 77.0mm iso800
03-30-2007, 06:34 AM   #12
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You can do the test:
Test: Are you VPN sensitive?: Pentax SLR Talk Forum: Digital Photography Review
03-30-2007, 07:09 AM   #13
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How much 'push' in photoshop (or other editor); how much personal experience with push/pull shooting/processing in general (including film)?
03-30-2007, 07:18 AM   #14
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See photo fragment:

Last edited by jfdavis58; 05-07-2007 at 10:18 AM.
03-30-2007, 08:11 AM   #15
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I have not experienced VPN but I am wondering if this is only in JPG. Does it only appear or get worst after processing into JPG, in camera or out?

I have doubts it shows up in RAW as it is a sensor dump. I might be wrong. If it is common in JPG transformation, in and out of camera, then it can be fixed to some extent. Noise at higher ISO causes strange patterns which JPG algorithm has a hard time handling. I would take the same image in RAW and process it to TIFF or other mode to see if the pattern still exists.
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