gray balance before taking photos and GTI N8

[mechman]

JimP wrote:

Hi boys..............can a pro photographer join into the discussion?

To tell you the truth Jim, you the kinda person we've been looking and waiting for! Thanks for joining in! Now I've got read all these posts and get caught up. I'm sure I'll have a couple questions when I'm done!

[mechman]

JimP wrote:

Then you have the flip side of this where you record the scene as neutral as possible or what I do, which is to shoot the scene using the camera raw format and then in photoshop CS2 use the tool in raw converter to white balance the scene. For this to work, you need a known neutral color in the scene such as either a known white or know neutral gray.

This is exactly what I intend to do. Which is why I purchased the Whibal card.

JimP wrote:

From there, for my use, I usually look at the scene and ask myself if the picture looks too warm or cool relative to a reference "shirley" (which is a reference image of various typical scenes and what they look like). As another poster mentioned, mixed lighting will be a problem and you often have to make judgement calls as to which color balance is more attractive.

"Eyeballing it" is what I've been doing so far. But it's tough. Mainly because it's a projected image with varying degrees of ambient light. I take some in darkness and then ramp up the ambient various stages until it's full ambient light.

JimP wrote:

As to photographing an interior scene with consumer grade cameras, the best advice I could give you is to avoid auto white balance and set the camera as follows. If its a room lit with light bulbs, use the tungsten setting on the camera. If your photographing a projected image on the screen in a totally dark room, use the white balance setting for either a heavy overcast day or a clear day under a tree. These setting are usually pretty close to 6500K. Most digital cameras have one or the other.

I have an Olympus E-500. I have used both auto and incandescent(tungsten). They usually end up close to identical - white balance wise.

JimP wrote:

Any questions?

Oh good golly yes! First the question, how do I white balance screen shots using the whibal card? Now a couple screen shots to help with my questions:

Full ambient light shot:



Medium to low ambient light shot:



Dark shot:



What would be the correct procedure for white balancing using the neutral gray card in these shots? Would it be best to set the card down in front of the screen using the ambient light? Or would it be best to take a shot with a white light projected onto the screen and the card on the screen? Of course doing this with each stage of ambient light. Thanks again for piping in Jim! It is appreciated!

[mechman]

wbassett wrote:

This thread is getting to be very interesting.


Interesting because elsewhere when I had a very similar thread going about camera setup and how to take accurate pictures of screen shots, the resident heavy that shows the most of these type of pictures only recommended auto everything.

It is getting good isn't it? I always knew it didn't get enough 'airtime' elsewhere. And now that we have a pro joining it... well I'm happy. I'll leave it at that!

Bill you know as well as I that when that 'resident heavy' talked, we all donned the mudders! Those would be knee boots for working in the muck folks. That guy threw alot of garbage around... still does.

wbassett wrote:

I have a Fuji S3100, not the best camera out there by no means, but also not the worse. I guess for a consumer and taking typical pictures that people shoot, it's a good camera. I have been able to get screen shots that look okay, but none look as good as it does in person, or as good as other people's screenies.

My interest is to learn how to take the best (most accurate) pictures of a screen without any software manipulation. Some people have pulled their images into Photoshop and cleaned them up there, but that leads to a lot of debate on photo manipulation and making the picture look better than it does. Everyone does agree that screenies are eye candy and not an ideal way for people to be judging screen performance, but since the people viewing various screen methods can literally live a thousand miles apart, sometimes a picture is their only 'reference'. (which is why I also like screen specs and data on them)

I'm looking forward to seeing more in this thread and what ideas and tips come up!

Your pics have always looked good to me. And I can say that I've never cleaned up any of my shots. I have varied shutter and aperture settings. ISO is always at 100. Shutter and aperture values are something that I'm going to try and include. Hopefully I'll remember that! When kenyee brought up white balancing elsewhere it was kind of eerie for me. I was actually thinking about it quite a bit but never thought to ask. I'm happy we found a forum with some help available!

[mechman]

JimP wrote:

Fluorescents are a special problem in that they have a discontinuous light distribution and come in many flavors. With that said, there is a specialized flourescent bulb that I use to use to judge color balance in prints from my color darkroom that were suppose to be much more accurate (not the double peak in the reds) and aimed at something like 5200 kelvin.

So I might be of some good to this thread, tell me exactly what you're trying to do and I'll see if I can help.

It sounds like you're trying to photograph on screen images in a dark room and the home theater room with just ambient lighting without a projected image on the screen. Am I close?

You've nailed it on the head! See my post above for questions about how I should accomplish this. And thanks a million again!

[mechman]

kenyee wrote:

It would be interesting if you could measure a whibal card though ;-) So now I'm wondering if I can take the whibal card, go to Home Depot or Sherwin Williams and ask them to mix up a can of paint that matches it...

I'd say give it a shot. What do you have to lose, you only have to buy a quart of it. Heck I may do this myself.

[mechman]

JimP wrote:

ken,

You're right on about the whibal card provided the card is illuminated with the exact same light as the screen...up to a point. Some materials reflect light differently, but what you're doing is as close as you can reasonable get it.

If I'm understanding what you're saying, I should project a white light with the projector onto the screen and place the whibal card there, right? And then take my successive shots using that first image as my reference? And I would think I would do that with each change in ambient light, right?

JimP wrote:

As for photographing a projected image with ambient lighting, tell me if we're talking daylight screaming through windows or room lighting at night and which kind of bulbs.

Maybe if you can provide a link I can tell better what we're talking about.

I posted some pics a ways back. But it can be either or both for most folks. If I'm watching early in the day, I have some filtered outside light coming in. At night there's usually incandescents lit up.

[wbassett]

mechman wrote:

What would be the correct procedure for white balancing using the neutral gray card in these shots? Would it be best to set the card down in front of the screen using the ambient light? Or would it be best to take a shot with a white light projected onto the screen and the card on the screen? Of course doing this with each stage of ambient light. Thanks again for piping in Jim! It is appreciated!

Jim mech nailed it as far as some of the things I want to figure out too!

[wbassett]

mechman wrote:

Your pics have always looked good to me. And I can say that I've never cleaned up any of my shots. I have varied shutter and aperture settings. ISO is always at 100. Shutter and aperture values are something that I'm going to try and include. Hopefully I'll remember that! When kenyee brought up white balancing elsewhere it was kind of eerie for me. I was actually thinking about it quite a bit but never thought to ask. I'm happy we found a forum with some help available!

They look okay I think, but not as good as what I see on the screen. And then there was the time that while set to 'auto' my camera introduced color shift and people were all over the screen shots saying it was a crappy application.

That's basically my background and interst in this Jim... to be able to take pictures that are accurate to what I see on the screen.

Thanks for jumping in here and lending a hand.

[mechman]

Alright I've done a bit of testing and I've found out that using the whibal card off of the screen to attempt white balancing doesn't work. As I was setting up the shot and looking at it I realized how ridiculous it was. With the image on the screen being as bright as it was, the whibal card was in darkness - even in medium ambient light. The resulting "balanced" pictures, after adjustment in photoshop, took on an extreme blue push. Unfortunately I cannot post the result. Being disgusted with myself for even thinking of it as a possibility, I discarded the images - quicker than the recycle bin could save them!

I then set up the whibal on the screen and looked for what to use to project my white light on the screen. The few that know me here know I've always got a hockey game saved. So ice it is! I took two shots each of low - no ambient light, medium ambient light, and high ambient light. I then took shots of Bugs! A Rainforest Adventure. As soon as I'm done with the conversions I'll post them.

But first a quick question for anyone here (and reading this for that matter). My thought process has me thinking that the ice shots I took, of each ambient light value, could be white balancing reference shots for good. Meaning I shouldn't have to retake them every time I take new shots, I could use the ones I took today. I'd appreciate anyone's input on this. Does it sound valid? I do know that tonight I will take 6 more reference shots when there's no daylight coming in. What do you think?

[JimP]

O.K., anyone live in or around Montgomery or Wetumpka where I can come over and do some live testing? or I guess I can pull out my projector. Forgot I had one.

I want to answer everybody's question which in part will require some research into each camera that's mentioned. I've got something I want to try first.

Be back in a few minutes.

[mechman]

Nope. I'm way north of you! I have to do a little more reading on the whibal card and how to do batch processing of white balances. Right now it seems extremely tedious to me and I know that there's got to be a better way. I'm off to soccer and T-ball with the kids for the evening. I'll be back later. Hopefully I can figure this all out shortly.

Jim,

From what I can tell, you have to set the white balance from the projected image. And I figured I'd have to use a white image. Do you think I can save these white balance figures and use them 'easily' for subsequent shots under the same lighting environments in the future? Let me know what you think...

[JimP]

mechman,

Using your E-500, use this one touch white balance procedure on page 90 of this pdf from Olympus.
http://www.olympusamerica.com/files/...d%20Manual.pdf

You will want to do this with each room lighting situation with your white card and a clear white projection from your projector. White snow is typically a little blue, so that would likely scew your color balance. Be sure to fill the camera viewfinder. One thing to think about is that your projected image should be based on 6500k, where your incandesent lights are somewhere between 2800 and 3400K. What they are likely doing is affecting your projected shadows more than the highlights. Color balancing for these type things generally presumes that everything is shifted an equal amount which isn't your case.

Using the white card rather than the screen to perform the white balance procedure above will shift your color if the two are different. You might do as well using the white card when you are comparing screens to more accurately contrast the differences in the screens. Otherwise, if you are just wanting to show an image off of your screen (provided its different than the white card) make the white balance measurement off of the screen.

What kind of bulbs are those in the ceiling?

[JimP]

kenyee,

Is this the manual white balance you're referring to in your earlier post? http://www.fujifilm.com/products/dig...es/fxf30_e.pdf page 70 under "Custom White Balance".

[JimP]

wbasset

Unfortunately, your S3100 doesn't have a custom white balance function.

The closest white balance setting is going to be Daylight, which is probably 5200K. You'll still be 1600K off provided your projector is putting out 6500K.

Page 42 under "white balance" http://www.fujifilmusa.com/JSP/fuji/...100_Manual.pdf

[mechman]

JimP wrote:

mechman,

Using your E-500, use this one touch white balance procedure on page 90 of this pdf from Olympus.
http://www.olympusamerica.com/files/...d%20Manual.pdf

You will want to do this with each room lighting situation with your white card and a clear white projection from your projector. White snow is typically a little blue, so that would likely scew your color balance. Be sure to fill the camera viewfinder. One thing to think about is that your projected image should be based on 6500k, where your incandesent lights are somewhere between 2800 and 3400K. What they are likely doing is affecting your projected shadows more than the highlights. Color balancing for these type things generally presumes that everything is shifted an equal amount which isn't your case.

Using the white card rather than the screen to perform the white balance procedure above will shift your color if the two are different. You might do as well using the white card when you are comparing screens to more accurately contrast the differences in the screens. Otherwise, if you are just wanting to show an image off of your screen (provided its different than the white card) make the white balance measurement off of the screen.

What kind of bulbs are those in the ceiling?

They're incandescents. I've done white balancing as per the manual with a sheet of paper. The results were that bluish picture above. This pic is from white balancing using the white ice in the screen. You can see the whibal card on the bottom. But this in and of itself is ticking me off, I never realized how much you lose going to jpeg. But that might have to be a whole different thread some other time.



So when I hold the whibal card and white balance the camera using it, do I use the ambient light or should I project a white light? Thanks for the help Jim and you can call me mech (like mechanic), that's what my friends call me.

[JimP]

mech,

Start with taking a reading (whether its off of the white card or the screen) with projector only if you are in a totally dark room. With combination lighting, take a reading off of the screen with both the projector and incandesent lighting on.

When you did the custom white balance shot that came out blue, did you have a white light from the projector or was it with room lighting. I would speculate that it was with room lighting. That would explain the strong blue shift with the projected image.

[mechman]

Room lighting. I read somewhere it may have been because the sheet of paper I used may have been bleached. Do incandescents always give out a blue push?

[JimP]

mech,

Also, open your aperature about 1 f/stop.

[mechman]

Well I've got the pocket whibal so I can't really use it as a manual white balance card. Can't get the white on it to fill the lense. I have DirecTV though and their new 'theme has a lot of white in it. I used that. Between that and bumping the f/stop up one it seems to have worked. The nice part is I can save the image on the camera as a jpeg after the manual white balancing and it looks a lot better than the one I converted earlier in Photoshop.

Here's the earlier on top and the new on the bottom.





The original RAW file for these two pictures seem identical in color, brightness, etc. It's amazing how much was lost converting it in Photoshop as opposed to the camera saving it as a jpeg.

[wbassett]

JimP wrote:

wbasset

Unfortunately, your S3100 doesn't have a custom white balance function.

The closest white balance setting is going to be Daylight, which is probably 5200K. You'll still be 1600K off provided your projector is putting out 6500K.

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