VPN...What Gives?

[benjikan]

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

[Didache]

I have also heard and read about this issue. However, like you, my understanding is that this effect only occurs when the absolute boundaries of ISO and exposure are being pushed, with huge areas of shadow. In other words, not something people are likely to see unless they do nightclub photography, etc. I have also read on a forum that this problem MIGHT be caused by the battery in the grip causing some kind of interference.

Mike

[danag42]

I've only seen the situation in extreme underexposed sections of an image. Since getting the new firmware, I haven't seen any. But I generally take well- lighted and well-exposed studio images.

[mutleybird]

I have also read on a forum that this problem MIGHT be caused by the battery in the grip causing some kind of interference.

Mike

This is horizontal whitish lines, not VPN. The nake forthat has become HPN, and some grips cause it. Seems to be something in the grip battery circuit.

The new 1.11 firmware doesn't have any effect at all on either issue.

Larry

[mutleybird]

I tend to believe that if ones exposure is correct within reason, that this issue does not crop up.

Ben

It does in its usual circumstances.

much more in High ISO like 1600.

Absolutely correct, perfect exposures with darker mid-shadow regions (concert photography is just one good example), artistically, puposely chosen low-key photography.

Even a bit in a shot I took yesterday at ISO 1600 in the out-of-focus blue hat area at the bottom of the frame.

http://mutley.hypermart.net/RedheadZombie.jpg

[Didache]

mutleybird .. absolutely right re the grip. My mistake - I had conflated two separate problems in my mind.

Cheers
Mike

[benjikan]

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".

I have laoded the image in my photo gallery.

[ken1953]

Ben, I think you need to wash your mirror and clean your shelf...haha
Ken

[benjikan]

Ben, I think you need to wash your mirror and clean your shelf...haha
Ken

Yeah pretty disgusting. I guess you can see that my girlfriend is on vacation and I am playing the slob mouse while the cat is away...I'll clean up today. Promise.

[Photo-John]

It does in its usual circumstances.

much more in High ISO like 1600.

Absolutely correct, perfect exposures with darker mid-shadow regions (concert photography is just one good example), artistically, puposely chosen low-key photography.

Even a bit in a shot I took yesterday at ISO 1600 in the out-of-focus blue hat area at the bottom of the frame.

http://mutley.hypermart.net/RedheadZombie.jpg

I don't see anything wrong with the image you linked to. What should I be looking for?

By the way, it would be wonderful if you would post a review for your camera. We need more reviews for the K10D, please!

[cyberlord]

I don't see anything wrong with the image you linked to. What should I be looking for?

If you look at out of focus hat in the foreground (lower left) you will see what appears to be vertical lines. I find on my photos that the noise (grain) from the OOF areas shows more than infocus areas and that's on the DL whether in shadow or highlight. Somehow it seems like how the digital is rendering the bokeh.

Just my observation on my photos for the last year.

[cyberlord]

Even a bit in a shot I took yesterday at ISO 1600 in the out-of-focus blue hat area at the bottom of the frame.

http://mutley.hypermart.net/RedheadZombie.jpg

Could you post a 100% crop of that area? I'd like to see how it looks at full resolution.

Thanks

[cyberlord]

Here is an example of my horizontal banding that I get on my DL. It doesn't bother me so I'm not worried about it.

http://gallery.photographyreview.com...&ppuser=247011

[mutleybird]

By the way, it would be wonderful if you would post a review for your camera. We need more reviews for the K10D, please!

I don't know what type of review you are looking for, but I have found my K10D to be a far more effective high quality image tool than the Canon 400D that I had for about a week. Once you get the settings tweaked correctly, even the jpegs have far better color accuracy.

The only instances of less noise on the Canon were found to be because Canon has more automatic in-camera noise reduction so blurs a bit more detail as well.

I still feel the K10D is the best of its type in image quality along with its better build and fit & finish, even though I wish Pentax would correct a few niggles with a firmware update.

1) I feel they should improve the jpg processing for a better tone curve closer to how well its RAW files can be interpreted by outside programs like ACR or Lightroom with an eye toward increasing Dynamic Range like the 22-bit processor advertises.

2) Add an edge sharpening algorithm as a menu option so those who need to save post processing time can choose this instead of the dark halo sharpening Pentax uses:

CUSTOM MENU>

.................SHARPENING>

......................1- DEFAULT
......................2- EDGE USM

3) Solve or minimize VPN so there is more usable Dynamic Range in the Shadows. The range is there (so far in RAW), but gets cut short if VPN begins to show. If the noise was patternless, it would be no problem.

4) When in Auto-ISO and HyperProgram, for example indoors, the range being 100-800, the K10D will start off at ISO 800, and as you slow up the shutter speed, the Auto ISO will lower the ISO until it reaches 100.

Then, you will not be able to choose faster shutter speeds because the ISO will be locked at 100. In other words, you can't reverse direction, expecting the ISO to go back towards 800.

One manager at Pentax was told about this, and just said this is how we "designed" it, so it will not be fixed. I think this should be fixed aka designed better.

4a) Also on tweaking Auto ISO, as per a suggestion by the indubitable Ken Rockwell:

"If using auto ISO in auto, Av, or program mode, the k10d should stay at your chosen lowest ISO value and allow you to set a shutter speed threshold at which the ISO will change to the next highest or lowest level needed to maintain proper exposure at a given aperture."

5) A menu option for Noise Reduction levels that can be user defeatable to preserve Pentax philosophy of no noise reduction (unlike Nikon where it can NEVER be turned completely off - even in RAW)

All of this is almost completely doable in a firmware update, and would make the K10D an even better tool than it already is, and would make a lot of common concerns into non-issues and get people off the fence in buying a K10D. Pentax even has mentioned they might use firmware to introduce 16 bit RAW files ( as originally intended) hopefully taking more advantage of the 22-bit PRIME processor.

Hopefully they realize the importance of doing this (and the maybe some of the other tweaks) for the current already sold K10D cameras that people invested $1000 in, rather than making the decision to focus on including these things in the K10D replacement scheduled to come out already in the fall.

Larry

[mutleybird]

Could you post a 100% crop of that area? I'd like to see how it looks at full resolution.

Thanks

There are much better examples as it is minimal here and just a shot I happened to have just done, but here it is with no processing at all.

http://mutley.hypermart.net/VPNcrop.jpg

Larry

[ken1953]

Hi Larry, nice review...what John was referring to is to please post a review in our "Reviews" section. You can link to it here or at the link at the top of each page, where it says "Write a Review"...under the Reviews Tab.
To make things a bit easier, you can copy and paste most of your review post here, over to the review section. The instructions are easy and the layout for posting is self explanatory.
As reviews moderator, I look forward to seeing many reviews from you. Also, if selected, you could win a nice prize in our Reviews Contest, so the more reviews you post of different equipment, the better chance you have of winning.
Thanx,