Photograph Works

Introduction and ConclusionThe purpose of this test was to see what degredation of the image would be caused by using high ISO settings on the camera. My conclusion is that even the highest ISO settings are useable, and certainly 800ISO can be used as a matter of course, without worrying about degradation of the image.

My long-time experience is that plenty of light thrown on the subject also helps – so very low light shots may well still show chroma and luminance noise in deep shadows.

Which begs the question of why use high ISO if there is plenty of light about? The answer is that higher ISO enables higher speeds to be used, which is great for moving subjects; and a high ISO sharp shot is always better than a low ISO clean file, but blurred, shot.

A note on ISO
For those not familiar with the term ‘ISO’, it is a measurement of the camera’s sensor sensitivity to light. The higher the number, the greater the sensitivity. The term is a holdover from film cameras. Each film is made with a specific sensitivity.

As there is a relationship between the sensitivity of the film, the shutter speed and the aperture that can be used in a given situation, photographers are always looking for the optimum combination that will give them the best image quality. With film, the greater the sensitivity, the higher the shutter speed that can be used, as less light is needed to burn the image into the film.

But higher sensitivity comes at a cost and the cost is the increasing appearance of grain in the image. The particles or (or dye clouds in the case of colour film) become more visible, the greater the sensitivity of the film.

But what about digital cameras, which have no film? Surely they always have the same sensitivity, after all there is no film and it is always the same camera? Well, increasing the ISO in a digital camera is apparently a matter of increasing the sensitivity of the the chip/circuitry. But as with film there is a downside, which is that in the ratio of the signal to noise, there is more noise (the digital equivalent to grain) compared to the signal.

Or rather, in this fast-moving digital world, the downside is becoming less of an issue as time goes on. For the detailed results – read on.

The Results
I shot these images in RAW and opened them in Photoshop CS2 with my default RAW conversion set-up, which has no sharpening, luminance smoothing, or colour noise reduction. Each image was then Saved-For-Web with no sharpening or colour correction.

The photographs were shot with the 18-55mm kit lens with the focal length set, according to the EXIF data, at 48mm.

The shots shown here are crops of a few hundred pixels from near the centre of the image. I set up a standard crop size for the crop tool in Photoshop and cropped each of the shots to the same number of pixels.

For comparison purposes, the first shot is taken with a Nikon D200 with a 50mm lens and set at 100ISO.

CLICK on any of the photos for a larger view.

D200 at 100ISO

D40 at 200ISO (the lowest ISO setting for this camera)

D40 at 400ISO

D40 at 800ISO

D40 at 1600ISO

D40 at Hi-1 (3200ISO equivalent)

There is more detail in the shot from the D200, but that is to be expected given that it has a larger sensor and that the 50mm lens is probably sharper than the 18-55mm kit lens on the D40. Nonetheless I think it is clear from the shots that even the highest ISO is useable.

Of course, I want to know whether whatever differences there are between the shots, would be visible in a print. I read somewhere that looking at an on-screen shot at 25% gives a good approximation of what can – and cannot – be seen in a print. If that is so, then these crops are certainly a stringent enough test.

I have not printed these images. Some time ago though, I printed a portrait I took at 800ISO shot on the D200 with 105mm f2 DC lens (a very sharp lens) to 20×30 inches (45x150cm) and it looks as smooth as one would want. Or rather, it has an ever so slightly sketch-like look if one looks very close; which is how I have found that the D200 tends to render images at high ISO. For portraits it is very appealing.

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Bridge is much quicker and much, much more stable than in CS2. I hated Bridge in CS2; so much so that if I did not have it open I would sometimes rather go to file/open in Photoshop and trawl through the images in the folders on the computer, than go to Browse and watch the clunky Bridge program open and struggle.

All that is changed now with Bridge in CS3. Now it is a pleasure to use and let’s you get right on with finding what you want.

After 16 days use it has not crashed on me once. It has however told me on two occasions that it has quit unexpectedly, but on both occasions I had just closed the program. So whatever it said, it had not crashed at all, in fact. I have had that happen with Bridge CS2 also – strange bug.

It has a nice Preferences panel to set the background (from black to tones of grey to white) for the images and for the data, and for the highlighted folder. Very nice on the eye. And there is a nice crossover point where, if I set the background darker than a certain point, the text changes from black to white – a necessity otherwise the text would be invisible.

The layout and sizes of the panels (folders, thumbnails, large version, metadata etc) can be changed to suit, and and allows a nice big view of the chosen image.

Bridge does stacks, keywords, sorts, labels, and slideshows like Lightroom does, but it does not have all the output options (print, Web, batch process) that Lightroom has. So for batch processing jpeg images for print or to a website, there is still reason to have Lightroom.

Photoshop CS3, however, has a script that will batch-make jpegs, PSDs or TIFFs. And it will make a web photo gallery, though I have not compared its capabilities with what Lightroom will do.

How long will Photoshop/Bridge and Lightroom remain two separate programs though? The stated philosophy was that some photographers wanted to process and batch process images and did not need the capabilities of Photoshop. That may be so now, but I cannot help but think that CS4 will surely incorporate everything Lightroom can do.

Photoshop’s RAW converter is a huge improvement. I was never happy with the lack of controls in the RAW converter in CS2 and the need to think in terms of further operations in Photoshop ‘proper’. It always seemed to me to be a bodge of a way to deal with images and probably a hang-over from the architecture of earlier versions of the program.

Whatever the reason, in CS3 it is now possible to get an image how you want it in the RAW converter before you open it. There is everything you might want to do in terms of the production of the unretouched image. The capability that I find I am using more and more, is fine-tuning the tone curve. The tonal range is divided into four sections from highlights-lights-darks-shadows and each has a slider. Using these I can fine tune the appearance in a convincing way.

The other capability I find I am using, are the hue/saturation/luminance sliders. Using these I can make very fine adjustments to the colors.

Photoshop
Once opened, the changes in CS3 are more subtle. It is quicker but for many operations the extra speed is not so startling. The tool layout is tweaked but not so different.

But what is better are the additional things that are hidden ‘under the hood’ so to speak. The features don’t jump out at you and so I have been looking at Russell Brown’s videos. I recommend them highly – they all free, and made by a major contributor to Photoshop’s development.

for example, smart filters for text is a joy.

The Refine Edges palette option within the Quick Selection Tool are a visual pleasure and the tool itself uses a selection method that enables the user to teach the tool what to include within the selection.

The subtleties of the Clone Stamp tool are great because they are so visual. In fact that is the characteristic that best defines the improvements in and additions to the tools. They are visual – you can see what effect you are making before you commit to your settings.

As of now- a success.