Comparison images Alpha 350 versus Canon 7D

[Javelin]

I bought a douglas grey card and must say I really like it. It was cheaper and made so much better than what the local camera shops sell. it's bigger too which helps ad i'v had really good luck with it.

http://www.photo-software.com/greycard.htm

[David Kilpatrick]

Well, I can't knock the Douglas Grey Card since we designed it - Ian Gee (the folding concept for contrast measurement), Douglas West (wanted a new grey card, used to make plain ordinary ones), me (realised that a vinyl ring-binder maker could manufacture this), Douglas again (sourced loads of samples of vinyl materials), Shirley (tested all the materials in the colour science lab at Heriot Watt University).

Paterson Photographic financed the production and it was called the Paterson Grey Card, Geoffrey Crawley (as a consultant to Paterson) approve of the technical stuff behind it. Then Paterson went broke owing us lots of money, as always, and owing Douglas. So the card became his card instead. I believe it's now being marketed by Paterson again after a gap of some years.

David

[ECam]

Hello David, I will be very interested in your assessment of this "white balance lens cap". I will keep checking for your posts on the subject. Thanks.

Edward

[Vidgamer]

Hi David, didn't realize that you were shooting in studio with a flash.

The white balance lens cap I was talking about is brand named "Mennon". The web site is http://www.mennon-usa.com.

Sorry to get off topic (discussion of the difference between the Sony A350 and the Canon 7D), but I was looking for a discussion of white balance calibration and the devices used to set custom white balance in a DSLR. I could not find one on this site and it appeared that the tonal differences of the two cameras might be a white balance issue, had they not been shot with a flash.

I purchased a Sony A350 recently (my first DIGITAL slr) and have been researching the subject of white balance, having learned how much proper white balance can influence a photo. I have been experimenting with different light sources, attempting to adjust the custom WB for each shot and ...

Yeah, if you do jpeg, wb becomes important. I still use auto most of the time unless indoors (with lighting).

I got the Mennon cap, but I have some reservations. First of all, it gives a cooler color cast than when I use my grey card. My friend's expensive Expodisc works much better in mixed lighting too. Here's a case where it may be better to pay more.

[UrsaMajor]

Yeah, if you do jpeg, wb becomes important. I still use auto most of the time unless indoors (with lighting).

Personally, I use a white balance card even for RAW images. I find that it gives me a "standard" starting point and reduces the post-processing work involved in getting to the final image. Obviously, there are occasions - photos taken at sunset, for example - where I actually want "off-color" images, but having a known starting point can often be a big help in getting to the end result.

I got the Mennon cap, but I have some reservations. First of all, it gives a cooler color cast than when I use my grey card. My friend's expensive Expodisc works much better in mixed lighting too. Here's a case where it may be better to pay more.

FWIW, from the investigation that I have done, it appears that the classic "grey card" was not intended to provide an accurate white balance. They were designed to provide accurate exposure for Black & White film and will also provide correct exposure for color film and for digital cameras. However, as far as I can determine, the correct exposure does not guarantee correct white balance unless the card is also designed for that purpose - and most are not.

Personally, I have a couple of cards that I use to set the white balance - one that is about 10x15cm, and one that is about the size of a business card that I have attached to a lanyard around my neck. I use the camera's meter to set the exposure on an initial shot and then adjust the exposure if necessary, based upon the histogram and a judgment factor that compares the image with the histogram to see if there are unimportant parts of the image that seem to be affecting the histogram.

With best wishes,
- Tom -

[David Kilpatrick]

The Douglas (or Paterson) Grey Card provides an accurate WB from grey. Shirley selected the material used based on equi-energy spectrum flat response (that means - no peaks or colour bias). The Kodak Grey Card was the reason we did the research for the Douglas card - it is actually quite strongly magenta, not neutral grey at all.

David

[UrsaMajor]

The Douglas (or Paterson) Grey Card provides an accurate WB from grey. Shirley selected the material used based on equi-energy spectrum flat response (that means - no peaks or colour bias). The Kodak Grey Card was the reason we did the research for the Douglas card - it is actually quite strongly magenta, not neutral grey at all.

That's what I found when I was looking into the subject after I bought my Minolta A2 in 2004 and first encountered the White Balance issue as related to digital cameras. After investigating what seemed to be available at that time, I ended up purchasing a WhiBal brand card, partially because of the convenience of being able to carry a business-card sized card on a neck lanyard. However, the manufacturer specifically said that it was guaranteed to provide accurate color balance, but that it was not intended to provide 18 percent reflectively for exposure control - essentially the exact opposite to the Kodak Grey Card.

With best wishes,
- Tom -

[Vidgamer]

I got the Mennon cap, but I have some reservations. First of all, it gives a cooler color cast than when I use my grey card. My friend's expensive Expodisc works much better in mixed lighting too. Here's a case where it may be better to pay more.

FWIW, from the investigation that I have done, it appears that the classic "grey card" was not intended to provide an accurate white balance. They were designed to provide accurate exposure for Black & White film and will also provide correct exposure for color film and for digital cameras. However, as far as I can determine, the correct exposure does not guarantee correct white balance unless the card is also designed for that purpose - and most are not.

And yet, I prefer the results (over the cap). Perhaps it helps that it's not a Kodak card.

I agree that it would be desireable to have something calibrated. A cap would be more convenient than a card, I would think.
[/quote]
Personally, I have a couple of cards that I use to set the white balance - one that is about 10x15cm, and one that is about the size of a business card that I have attached to a lanyard around my neck. I use the camera's meter to set the exposure on an initial shot and then adjust the exposure if necessary, based upon the histogram and a judgment factor that compares the image with the histogram to see if there are unimportant parts of the image that seem to be affecting the histogram.

With best wishes,
- Tom -
[/quote]