Wednesday, March 21, 2007

Some Tips For Great Screen Shots

I have recently learned how to capture great screen shots from my HT and have decided to post a quick how to here. I am by no means an expert in photography, but would like to share these easy tips so hopefully you too can capture great images [and not just in the HT]. The real beauty of a digital camera is the ability to preview [and delete] all shots in the field so that you only take home the best photos. No more waiting and hoping!!!

I am using a Fujifilm Fine-Pix S5600, so the following is based on using that camera [and may apply to other Fujifilm models]. If your using a different brand, chances are that some of the features will still be labeled the same...

TIP: Always use a Tri-Pod

A tripod is essential for great screen shots as it completely removes the possible human error of hand shake from the shot. Combined with the self timer function, your shots will look like a professional took them as well as give you the opportunity to take several different shots from the same camera angle.

TIP: Use the Single Auto Focus or S-AF function.

When capturing a screen shot, I have found that best results come from centering the paused image in the frame, focusing that image and then capturing that image. Therefore a single focus is all that is required. To assist with this, the rear LCD display has a grid function [found by using "disp/back"] to help align the camera [now mounted to the tripod] to get great shots.

TIP: White Balance the camera for each shot.

This was the hardest part for me to grasp. Not the method, but the term - just what is white in the real world? In video [and other electronic imaging displays], equal amounts of Red Green and Blue equal grey. If that level of grey is 255, then the colour we see is absolute white. But in the real world we seldom see white in such a pure form. General lighting conditions will change our perception of colour. White balance helps restore the colour balance in the camera so that the captured images will appear more natural. Also in video, our test patterns are referenced from PC levels so we know that video white is 235 and that anything above is above video white, but there is no such levels in the real world.

When capturing different aspect ratios on the screen, the amount of light to the CCD will change. This can actually shift the final colour balance of the captured image even if that image is the same paused image. I recently discovered this when capturing screen shots for this site.

Both of the shots [above] are the same paused image. The first shot was captured using "auto" and the second shot was white balanced. Notice the colour of the second shot is much more natural, where the first shot looks as if viewing through a mild blue filter. All the screen shots above were captured from a 720 DLP projector and the first two shots used the AUSSIEMORPHIC LENS. The last shot was generated by my CIH system using a 480 LCD projector.

TIP: You may have to adjust the ISO.

A photo is an image of captured light and the technique applies to both film and digital cameras. ISO refers to the sensitivity of the photographic elements [film or CCD] that captures the image and will greatly effect the quality of the final shots. With film, you are limited to the one type [ISO value] of film stock loaded, but with digital, you can change the ISO value on the fly. I generally start at ISO 400 and change if need be.

Capturing those images.

I change the setting to from "auto" to "P" on the function dial. "P" stands for Program and this allows access to such features as white balance. I always use "custom" white balance which is as simple as scrolling across to the "custom" icon using the compass keys on the back of the camera. To set the white balance on this camera, you simply take a shot of something white. If there is sufficient light, the cameras displays "completed" and you lock that in using the enter key on the back.

The camera then adjusts the colour shift based on the lighting conditions to the levels based on the white balance. The interesting part here is that the white balance is taken from light reflected off the screen. The lights in the room are off, so this is quite reversed to normal white balancing.

Adjusting The Shutter Speed.

Depending on the how the image looks on the LCD display, you may need to adjust the ISO [found using the F key on the back of the camera] and even change both the appature and shutter speed settings which I am still working on perfecting. If you do change the shutter speed, you will have to use the timer.


With most of the screen shots I have captured, I have found that simply shifting the ISO to 800 helps if the "under" warning appears. It may add noise to the image as well as over saturate the whites [blooming or crushing]. However in the case of the shot above, I have actually brought ISO down to 200, and then decreased the shutter speed [using S on the top dial] from 0.6 seconds to 1.6 seconds. This means that the camera must be held perfectly still, so I've used the timer...