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

For those who understand VPN to mean Virtual Private Networks, I think Ben probably means Vertical Pattern Noise.

G
Confusing acronyms consultant

Thanks for the clarification. I realized I didn't indicate the meaning of this acronym.

Ben

I think that I read somewhere that an "undocumented" fix in Firmware 1.11 was for VPN. I'm just having a "senior moment" as I cannot recall where I read that!

I thought it was supposed to have been fixed in 1.10? certainly haven't noticed any since applying that patch although I haven't really had to use 1600 ISO since then either (fencing season is over).

Still haven't been able to get the Virtual Private Networking to work though.

According to the re-review this week in amateur photographer, one of the things fixed with the new firmware update is vertical green lines that some people had reported. I don't know if that is VPN but there you go.

Carl

I took this shot handheld at 1600 iso specifically to highlight the fact that I have not experienced any VPN (Vertical Pattern Noise) I wanted extreme highlights next to extreme shadows to illustrate this point. Converted from RAW to JPEG Medium resolution for upload purposes using Native ACR color settings in Photoshop "ProPhoto RGB" as my color space. I see absolutely no banding what so ever and was quite impressed with how clean the image was at 1600 iso "Correctly Exposed".

Can be viewed here:
http://gallery.photographyreview.com/showphoto.php?photo=66395&size=big&...

Well after being scared about vertical pattern noise before buying a K10D I can confirm it does definitely exist. Here is the thing, I would have never really noticed it unless someone had mentioned it to me. Secondly, it is made worse by viewing an image zoomed out, once you zoom to 100% it blends much better. It also seems to blend fine when printing.

It is only apparent at ISO 1600 on my camera and really doesn't bother me because unless I make large changes to exposure, fill light, contrast and brightness it isn't visible on the final result. Plus, I hate shooting in ISO 1600 because it is so noisy. A fair bit of detail is lost, especially after NR (probably an understatement).

BTW I'm using firmware 1.20

BTW, Silkypix includes "Geometric Noise" reduction which cleans up any VPN that might be lurking. Pretty excellent NR in general too... once you get the hang of it
Matt

It is a little soft for my liking and I've already got Lightroom. Of course I could PP all ISO 1600 shots in Silkypix...

I currently have Pentax RAW Lab, Lightroom, Capture One LE (Two licences) so I have a lot of options.

Unfortunately my DVD drive is dead so I can't install Pentax RAW Lab.

Must do my "how to" sometime... had zero problems with softness (and I'm a demanding chap )
Matt

The conditions to make that happen much be rather difficult, or is it that some cameras suffer where some may not??
I have tried to reproduce the effect back to when I firs got the K10D, but cannot do so either.

Although if I take a long exposure with he lens cap on, there is a significant more buildup of noise on one side than the other. That is another issue yet still no significant banding effect.

It's possible to force the appearance of VPN.

A RAW shot taken with some shadows is needed. In your preferred editing software, increase the exposure until the banding effect appears.

As Ben said, if the exposure is right to start with, there is little or no problem.

I rached the same conclusion if you read above.

It can be made apparent by artefacting caused by a repeated vertical pattern in shadows.

Hmmm, just took several hundred shots over the course of an hour last night at gig for a friend's band. I used my 50mm 1.4 lens wide open at ISO 1600 and still barely had enough light to take a decent photo. Most photos ended up with a shutter speed between 1/30 and 1/10 second (SR - what a godsend!!). FYI, firmware is 1.20.

Anyway, ended up with lots of grain, but not one showed signs of banding. OK, maybe if you knew what you were looking for, you might notice a stray line in a few of the photos. But there is nothing like I've seen reported.



Guess I'm lucky.