X-Rite ColorChecker Passport and PWP5

[doubtingtom]

I wil be purchasing X-Rite Mini-Colorchecker (Card only) ~$50.,or Passport (cards AND profile software) ~$100. for Custom WB and RAW PP of hiking image files from new Ricoh and Sigma compact cameras. When processing the colorchecker image, will PWP5/Color/MatchReference transformation accomplish the same thing aa the ColorChecker Passport profiling software ? If it does very similar functions, then there will be little point in the extra cost beyond the ColorChecker card itself. I have not used PWP Match Reference at all and will appreciate guidance. A major interest is the Sigma (DP!) X3F RAW files, and I do not believe Passport software would open them. If they were converted to DNG most of the RAW data might be sacrificed.

Regards,
Tom B

[doubtingtom]

Here are examples of the problem I'm trying to deal with. All taken on tripod, very comparable settings, all within a few minutes, and all using a separate gray card image for WB. All converted from RAW with only WB adjustment and saved as 16-bit TIF .... resized and saved as JPG. I expect Sigma's Foveon sensor to produce a distinct image, but the differences here are notable. Perhaps using a ColorChecker in future will still not yield major changes? After seeing Ricoh and Sigma results, I expected Nikon to be the 'unbiased' arbiter, but surprised when the image was so much like Ricoh (small Bayer sensor) versus Sigma (same size .. APS-C .. sensor).

Nikon D70 (NEF)


Sigma DP1 (X3F)


Ricoh GX200 (DNG)


Tom B

[ksinkel]

First the Sigma uses a very different sensor technlogy from the Ricoh and Nikon, so it is not surprsing that the last two cameras are more similar to each other than to the Sigma.

Even though you balanced your image using a gray card, the far away mountains still show a considerable blue cast (Nikon and Ricoh images). This is probably because the atmosphere itself is acting as a filter. It's effect becomes more pronounced with distance -- so your gray card is unaffected while the more distant areas are filtered. Try balancing your image by using say the white areas of the mountains as a refeerence. I believe you will filter out quite a bit of blue and thereby enhance the rust colored areas of the image. Also, try increasing saturation. I generally find a 30 - 40% increase is usual.

Kiril

[doubtingtom]

Thank-you for the explanation and ideas. Based on this analysis of the issues, are you also inferring that a ColorChecker in these images (or taken sequentially) will not add value in the context of 'correcting' or 'normalizing' this type of image .. when post-processing .. ?

Thank-you,
Tom B

[ksinkel]

Tom,

If you have a color checker (or can borrow one), I would certainly try it. However, for the fully calibrated approach to succeed, you have to take all significant factors into account. So in a situation like this landscape photograph, it may be more practical to use the color adjustment tools of Picture Window and adjust by eye.

Kiril

[doubtingtom]

I appreciate the support received and accept that the issues I posed are not easily solved in the context they were posted (ie. easy gray card, colorchecker, WB, 'fixes'). I am now left with reservations about acquiring and using either the X-Rite Mini ColorChecker card or Passport product .... specifically for landscape shooting. Surely there are some potential benefits, but I would enjoy from any comments from PWP users who feel these are truly helpful and who use them regularly. In the absence of 'enthusiastic' support, I will save the resources for other needs as they arise.

Thanks and regards,
Tom B

[jsachs]

When white balancing using a gray or white card, a lot depends on how the card is illuminated. If it is in full sunlight you will balance for daylight which is somewhat yellow; if it is in a shadow it will balance for skylight which is much more blue. The less direct the sunlight, the more skylight will be mixed in. In addition, balancing to pure white can remove the atmosphere of the image, especially at dawn and dusk.

[doubtingtom]

Jonathan, I do appreciate your comments and clarification. I will definitely do some very similar tests using a white card, although still facing the same size constraint (for hiking) and desiring one which I can 'protect' from damage. If there is an ideal 3" x 2" card ( or larger to be cut down ) ... that would work as well ... as long as the surface is a durable, matte finish to avoid the bright daylight conditions normally experienced here in southwest Utah.
I am still considering seriously the Lastolite LL LR1250 12" EzyBalance card (White_Gray) because of its ability to fold into a 5" size.
http://www.amazon.com/Lastolite-LL-LR12 ... 239&sr=8-2

Do items like the Prolite Full Color & White Balance Lens System with 110mm Disc offer credible improvement, or are they just gimmickry?
http://www.amazon.com/Prolite-Color-Whi ... 687&sr=1-1

I commit to no further 'pestering' on this issue, in terms of choosing products, but the Spring hiking season is very close here and some destinations are very special and rigorous to reach. Capturing the best possible image is so important ! PWP 5.0 is such a great tool for this goal, but the input is so vital.

Best regards,
Tom B

[jsachs]

Although some folks swear by them, I do not recommend white balance lens cap systems (Expodisc, etc.) - they just average all the light hitting the lens and use that as a white reference - a little like getting an ambient light reading from an exposure meter. The light hitting the camera lens may or may not be similar to the light hitting the subject. A white or gray card can be placed next to the subject or at least in the same light as the subject. In any case, the white balance from a card should be considered a starting point - you can always make adjustments to the white balance using the Color Balance or other transformations to get the desired artistic effect.

[doubtingtom]

Sincere thanks for adding your valued perspective. I'm feeling the larger (foldable) White card will be most helpful in landscape images like the one I posted in this Thread. Most of the scene is far from the lens and perhaps getting the card further away, and still a reasonable fraction of the total image, will be a positive step. Thank-you for your view of the ExpoDisc-and similar devices.

BTW, I'm feeling even more in need of this type of 'standard', having just done another DNG conversion of the same image file in a program called Raw Therapee. I used their Auto WB this time and .... for the first time ... produced a TIF which is very close to the Sigma image without additional processing. I did do a Color Balance in PWP 5. Compare to the Sigma file posted earlier. I hope I'm learning some of the key issues at this late date !




Regards,
Tom B