[mechman]

I have to say that I agree with just about everything being said here. Screenies serve a purpose in my mind. And that purpose is to augment the data. Data being the RGB values, xyY values, Lab values, and the spectrum image. I think the data itself tells you most everything you need to know. The rub comes when there needs to be a comparison. I think since the dawn of Black Widow we've done a ton of comparisons to paints that were supposed to be as good or better. And those paints gave us data readings that were in line with Black Widow. However, when it came time to see how they performed, they failed in every occurrence to live up to their billing. That's where photos come in handy.

The problem in photos though, is that they can be doctored. We've seen this in the past over at avs. Especially when one's business relies upon them - again avs. If one's livelihood creates a motive for this or one's ego, then that should be taken into account. Enough of that though! Time for some comments.

Harpmaker wrote:

Unless you are total newcomer to DIY screens, and internet forums dealing with such, you have seen a number of examples of screenies. The things are all over the place as people try to show off their home theaters, home-made screens or newest projector. There is nothing wrong with this, it can be fun to see such images; but, what do they really tell us? Most of the time, not much.

I wouldn't say not much. But when compared to the data side, I'd agree. Photos are useful for comparisons and great ways of showing what you're trying to say, such as hot spotting. But photos are definitely not the be all end all!

Harpmaker wrote:

Most people just use the auto setting on their camera. That's a bad way to take screenies or reference photos, and will lead to great frustration if the person is trying to show anything like the image they are seeing on the screen with their naked eyes.

Auto is what I use on my camera as it has shown me that it's capable of taking the shot depending upon the image being displayed. One f-stop may not be the right f-stop for the next shot. And same goes for shutter speeds. Constantly battling with the camera ends up being a battle with time. On my old Olympus 4000 I used to do manual adjustments, but not on my E-500. But you have to try and display what's being seen and that's a difficult task in extremely low lighting situations.

Harpmaker wrote:

The first step is to use whatever mode your camera has that will allow the user to manually set the white balance. Go into that mode and then project a solid white image onto your screen. There is one on the Video Essentials DVD, and probably other video calibration DVD's as well. After you have this image on your screen, go through whatever procedure your camera uses to set this screen as the white reference. This is the only way to be sure your camera will produce photos close to what you see.

Another way to do it is to use a neutral gray reference card such as the WhiBal. You can peruse the ins and outs of using that here. The nice thing about it is that it's not exclusive to screen shots and can be used in all of your photographing exploits. I've found mine extremely handy and very accurate!

Harpmaker wrote:

Now we come to setting the exposure time for the photos. Many times the camera will automatically set the proper exposure for the shot, but many times it won't either. The only thing to do is to take multiple photos of the screen at different exposure times and later select the one that looks closest to the true screen image.

Even with white balance and exposure taken care of we still have a problem, one I haven't found a good solution to yet. I'm talking about color saturation. I have taken screenies of a movie that seem pretty good as far as proper colors and exposures are concerned, but dad-burn it, the things are over-saturated! I'll show what I mean by this in a moment. Sometimes a camera will let you compensate for this, but most won't. In my case, my camera will only let me choose to have a more saturated picture!

Now comes the two biggies; contrast and dynamic range. Very few camera's, at least in the "point and shoot" category (read that as the cameras most of us have ), will let you manually set contrast levels, and NO camera I know of can manually adjust dynamic range; you either have an adequate amount or you don't (most don't).

Contrast and dynamic range are related, but it will take someone smarter than me to explain it properly. My first set of photos will show you what I mean though. they're coming up shortly.

In the end, our digital cameras are designed to make the best "normal" photo of whatever the camera is seeing. This is at odds with what we are trying to do with screenies. We are trying to show what our screens really look like to our eyes, but the camera is trying to make each photo look like it was taken in a perfect textbook setting, such as outside on a clear day in the middle of the afternoon with the sun behind the camera. In short, the camera is trying to make each photo "perfect" and not real. Sorry, at the moment I can't explain it any better than that.

With regards to exposure, contrast, dynamic range, etc, you get what you pay for. There are many things at play with each component including firmware, optics and the image sensor. The key here is tinkering until you get it right, all the while doing what you can to get them as accurate as possible - ie color balancing.

And this is also why I really disregard pretty much any photo - for judgment's sake - unless they're comparison photos. Don't get me wrong I love the screen shots of people's finished products and all. But they really are not usually the full story.

wbassett wrote:

Another problem is compression. The camera does it... then usually you have to resize the image for forum use, and some online photo hosting sites even add more compression and some even change the file format.

Compression is a problem. Especially with the online hosting and what not. But most cameras will let you shoot in RAW mode, which is the uncompressed image. The caveat being that the files are extremely large. I shoot all of my photos in RAW, as it's much easier to color balance them post production in Adobe Bridge.

wbassett wrote:

Screenies fall more in the eye candy category than anything, but certain ones can be used to demonstrate performance conditions, such as with ambient light levels. Some people rely solely on screen shot images as proof of 'empirical' data. That's fine, but most of the time it tends to be subjective.

This is why I think it's good to be discussing this! They are subjective and they have been abused... a lot (I'd say mostly elsewhere)! But you have to cater to your 'market' - for lack of a better term.

wbassett wrote:

Also it is really impossible to compare one picture to another. The only time any 'comparison' can be done is within the same picture.

I'm not so certain on this. If the lighting, the image, the settings on the camera, etc. don't change... I'll say maybe!

wbassett wrote:

I also have seen a lot of 'comparisons' between white screens and gray screens and those really don't prove anything. Of course blacks will look better on the gray and whites will look better on the white screen. The only way to do a comparison is like harp demonstrated, and that is by using test screen panels that are all similar in shade so the projector can be calibrated to all the panels.

Comparisons of white to grays is something that should never be taken seriously. The whites on my FG screen and on all the Black Widow panels look just fine to me. Right up until I put up a piece of Designer White. :raped:

Apples to apples, oranges to oranges.

As far as what type of content to show, the movie shots are primarily just eye candy. Most everything that needs to be shown via photos is readily available on the DVE, AVIA, or some other calibration disk. I prefer the checkerboard pattern for blacks and whites. There are solid color patterns for colors or there are color bars. But most of this stuff is moot as if you follow the guidelines we're trying to set forth - calibrate pj to D65 and project onto a D65 neutral screen - you will get everything you're looking for with regards to accurate color reproduction, skin tones, etc. Then it just becomes a question of 'do you want a bit more pop'? But that's a whole other can of worms...