Feature: Casio EX/F1 Image Quality Tests - first round of tests
Idea:The EX-F1 features for action picture taking are top rate, but how good are the images ?
A first review of the Casio EX-F1 reveals that its ability to take action shots in a number of modes are unique in the digital camera field:
1)60 6Mpixel stills at up to 60fps or 30fps or ... 2fps
2)6Mpixel still with shot triggered by motion sensor over an area of the screen set by the user
3)6Mpixel 3 bracketed images set for user chosen focus, exposure or white balance variations
4)Preshoot at up to 60fps second by half depressing the shutter release then on full release these "pre- exposed" still frames are saved so user is less likely to miss the optimum picture taking moment
5)continuous HD(1920 x 1080) movies at 60fps
6)512 × 384 movies at 300 fps
7)432 × 192 movies at 600 fps
8)336 × 96 movies at 1200 fps
These dynamic still and movie taking capabilities wrapped into one camera are simply not matched by any other digital SLR or video camera on the market. And to get the very fast video capabilities users will have to spend over $5-10000 or more (but also get larger video sizes).

The technical prowess of the Casio EX-F1 is very exciting (see more of technical review here)as it marries video and still camera capabilities for $1000 that are stunning. So what about the resulting images - both still and video, do they come up to snuff ? That is what this review is all about.

Still Image Quality

The tests used here are very similar to what was done for the Sony Alpha 350. Images are taken in the various Casio modes of operation and then no post processing is done on the JPEG images other than to crop the image so a relevant slice can fit on the page. Since the maximum still image size for the EX-F1 is 2816 x 2112, the long slices seen to the left and below are 350 x 2112.

The image to the left is an example of a simple still shot taken at f8.0, 1/50 sec using ISO 200. The autofocus was center weighted and the white balance was adjusted for cloudy Weather. The 35mm equivalent telephoto setting was 75mm. Image stabilization was on and Aperture priority was the exposure mode. Given the shading of the shop the colors came out very pleasing. Note that the whites are not bleached out and the shaded hues are not completely lost.

Subsequent processing of the image later (not this slice), was able to brighten the midtones easily for a more pleasing color gamut. In sum, I could live with exposure and color rendition, especially given the fast rate of snapping (I was out to test the Casio under quick snapshot conditions as well as tripod shots).

Likewise the autofocus performed reasonably well given the handheld shot, windy day, and relatively low f-stop setting. This image quality is certainly well matched for the website work that is one of my primary usages - see the final image at 600 x 480 on my www.pixoftoronto.com website.

This image would also easily do justice to an 8x10 inch print; however sizes beyond that would probably require a fair bit of addition photo finishing work on the image sharpness and the mid and shadow tones.

In general, at 6Mpixels, the Casio EX-F1 is really geared towards the point and shoot marketplace on the still image side. For example, the Sony A350 which has just been reviewed here, offers 14.5Mpixels with its still images and at $900 with a 18-70mm Sony telephoto lens is geared more to the fine art print side of the still image market.

But for fine art images there are a whole set of new SLR cameras coming to market that ar 10Mpixel or greater, have either image stabilization built into the camera body or advanced noise reduction and/or better highlight sensitivity. And these are mid-range in prices. A review of these SLR cameras will be available here for the interested reader.

A Bracketed Image

The next two images were taken down at the Toronto HarbourFront's Spring Circus Show at the Music Theatre. The first image below at the left is a auto-bracketed shot - 1 of 3 images taken at 2 stops difference in exposure. The chosen shot below is taken using f4.5 and 1/320 second at ISO 200. Again autofocus is used with spot metering and the white balance is set for Casio's Shade selection. The telephoto lens setting is at 250mm (35mm equivalent) and the base exposure is chosen by the camera using the Auto setting.

This is a monopod shot and it appears to have made a notable difference - the focus and sharpness of the image is pretty good given the 250mm zoom. Also because spot metering was used I was afraid the white shirt would either gray out or bleach out depending on where the final Auto meter reading was taken. But the Casio delivered a good sampling of white and off-white tones in the base shot - so in effect, the bracketing really was not required.

Finally the the hues, and particularly the skin tones, turned out remarkably true - a situation complicated by the cool, shady day. Again this shot is more than equal to the requirements for use on any one of my Web blog websites. See PixofToronto.com for examples.

A 10fps Still Shot

The second shot was taken using the EX-F1's vaunted fast exposure capabilities. I had set

Bracket shot

Rapid Burst mode shot

the camera for burst mode of 10fps - frames per second. This means a total of 6 seconds of shooting for 60 images in total. One of the disadvantages of burst mode is that it takes about 3-5 seconds for all the images to be saved away depending on what size of image one is taking. I was at the maximum 6Mpixel size. And as I suspected, there was some loss in image quality when using burst mode.

First, the image was taken using f3.2 and 1/1250 of a second using ISO 400 and Auto exposure mode. The white balance was again at the Shade setting and Image stabilization was on. And the sharpness and focus are reasonably good, although the man's foot is clearly blurred. However of even more concern is the fact the blue background is notably mottled and the gal's skin tones are seeping into the edges and onto the gray background.

Unfortunately users cannot take camera raw images when using burst mode. So it appears the two corrections are to take images in a brighter setting (this works pretty well) or to downsize the image and use the smaller still image sizes such as 2304 x 1728 or 2048 x 1536. The lower of the two actually worked reasonably well in the same theatre setting.

Again, with post processing and photofinishing the image on the right could be used for website work while the image on the left is almost ready to go as is. This means that pictures taken in EX-F1's burst mode require more photographic care and adjustment when employed beyond snapshot size or for website usage.

Video Images

I have had some problems using Casio movies with my video software mainstays - Adobe Photoshop CS3 and Adobe Premiere Elements. On video clips of more than 20MB in size I have had both programs crash. I have learned to do two things:
1)only run one or two programs when processing Casio movies;
2)use short clips, especially with HD size movies.
Now this is processing on Windows XP using 1.8GHz dual core Intel processor with 1GB of memory on Windows XP SP2. I have not yet tried the Casio supplied movie software - that will be at the core of further tests.

In the meantime I can report that the frames from videos taken at 720 x 480 30fps and 640 x 480 at 60fps are reasonably high quality. Take the shot below which used 640 x 480:

Again this image has no post processing done to it - its a straight clip from the video.The individual frame quality is very good. Compare the blue background above versus the burst mode shot at the upper right. The edges are soft and their is some bleeding of the skin tone edges into the background. But at 60fps, I am pleased with hues, sharpness and focus - at least as good as I got with 4 year old Panasonic and 6 year old Sony video cameras at the same resolution.

However, more video testing needs to be done. Especially, the HD and fast 300fps and 600fps modes. This will be the priority in Casio EX-F1: Image Quality II.

Summary

I can tell you I was quite pleased with the image quality results for the Casio EX-F1. The still images are nicely color balanced, true to the important skin tones, and the White balance corrections work well. For continuous shooting(burst mode), the focus is either marginally off or soft - but that may be a function of handheld operations at the shooting margins. Also bleeding/leeching of color occurred where dynamic action should be stopped. But downsizing and bright lighting appears to correct for this problem. Obviously I will want to check the different focus modes, telephoto settings, and exposure settings in Casio EX-F1:Image Quality II tests.

As for video I am more than pleased with those results so far with the exception of Adobe software's in ability to handle 20MB or larger video files without hiccupping from time to time. The clips of frames from 640 x 480 were almost immediately website ready. Typically website images are 350 to 600 pixels in width - and so these videos give me cropping space to spare. Again I expect the larger HD and faster 300 to 600fps videos to be image quality challenged. But lets wait for the test results.

In sum, the Casio EX-F1 is definitely a keeper for 8x10 portrait and other snapshots plus website work including YouTube video. Now the question is how robust is the camera when used in more extreme shooting conditions for both stills and videos. Stay tuned for Image Quality II.