8 tips for sharp photos

What I do (or should be doing, since -like everybody else- I can’t stick to my good resolutions) in order to obtain beautifully detailled photographs. It’s even more important if you want to make them ready for printing in large size (on your brand new A3 inkjet printer or poster-size at a print shop).

A quality lens

The first advice I should give it to choose a high-end lens. Even if the trans-standard zoom lens of the kit for most digital SLR cameras provide very good results in an exceptionnally compact form factor, that we all love to use. But these are also the result of so many compromises where image quality cannot be always the only factor.

Professionnal zoom lenses (the most expensive) are often capable of really impressive achievements, but prime lenses (with a fixed focal lenght) can reach quality levels that no zoom lens can reach. Some say that this is their unique (and only) selling point: Quality.

Thus, in the Minolta-Sony lens catalog, I rushed onto the white tele-lenses from the APO G pro family that, even today, produce exceptionnally good images (for a price no less astonishing if you don’t purchase them second-hand). But each serious camera/lens manufacturer has a few very nice lenses in its catalog.


Stop down your lens a little

Even the best lens is not perfect and its best is not reached at full aperture. Typically, you must stop down 2 or 3 stops to reach its best quality (check with the magazines quality analysis to know your glass top level).

Small ISO’s

In analog as in digital, it is difficult to avoid noise and loss of resolution when you pump the ISOs up. The rush for more sensitivity brings you defects that can go up to ugly. You must know your camera and the sensitivity range where images are the best (further than some values -400 ISO, 800 ISO, 1600 ISO- noise levels will become too annoying) and always stay under this limit whatever the temptation. Even better, try to use the basic core sensitivity of your camera (often 100 ISO, sometimes 200 ISO; check your user manual).

Say no! to vibrations

There are few things that can degrade sharpness as efficiently as vibrations while shooting. Vibrations of the camera, of the photographer, of the subject. If the latter allows it, use a tripod. It will allow you to stop down your lens, to keep a low ISO sensitivity and still be able to shoot.

If low speeds are impossible for the subject, choose a shutter speed as quick as necessary to stop the subject’s movements. For example, birds hardly accept less than 1/250s (many will prefer 1/1000s to freeze the attitudes).

No JPEG

In digital imaging, there is one common image format that degrades the local sharpness quite efficiently: JPEG file format. If the compression level is not too high (maximum quality) it can stay acceptable, but it will be best to work from a RAW format image. It’s richer and kept all the details available.

In the spotlight:

Perfect light exposure and careful image processing

But after shooting the image, it is still possible to crunch its quality down. First, be sure to perfectly expose the image. Some people will say that you can always correct later, but once you miss some information no post-processing will ever re-create it. If under- or over-exposure removes some information, it’s just lost).

Having a well exposed RAW image, be sure to limit processing to the strict minimum. Start withminor exposure and color processing. Don’t use any other tool (or minimally, and then…)

Touch up image size after pre-processing (in most case, you will also like to keep an original at full high-resolution before you proceed), then apply sharpening/accentuation (see below).

Save the image in a file format that will preserve all the details: Again, I recommend to forget JPEG and to prefer TIFF.

Sharpen/Unsharp

Nearly all digital images require some sharpening to bring some additional appearance of sharpness. But you must be very cautious here. So many good images have been lost by unwise sharpening.

Under Photoshop, use the Unsharp tool (USM).

To start with the USM filter, you can use the ones suggested by PhotographyJam, depending on the objective:

Subject Amount Radius Threshold
Soft subjects 150 1 10
Portraits 75 2 3
Moderate sharpening 225 0.5 0
Strong sharpening 65 4 3
All-purpose sharpening 85 1 4
For the web 400 0.3 0

Light!

But in any case, to reach all the other aims, you will need light. Enough light. But also, as any photographer will tell, a nice light, lighting oriented to best serve your subject. Your first and last concern will be light to have not only a sharp image, but a beautiful photograph.