How to improve sharpness

Chrisw · Jan 20, 2010

I have been trying to get some nice crisp pictures of a few of the snakes that I own and I am not liking how the pictures are coming out. Any tips and advice? I am using light tent that I made. A light on both sides and a light over top. I am having to go in lightroom to change the white balance.

I am using a d40x with a Nikon AF-s 18-55 DX VR

Before Lightroom

After Lightroom

Before Lightroom

After Lightroom

Natalie · Jan 20, 2010

Well the good thing is that you're shooting a Ball Python, which is probably the easiest snake to photograph because he'll sit perfectly still for ages.

I think the main thing here is your shutter speed, which is pretty slow at 1/60 sec. It's difficult to hand hold a camera at that speed and still get perfectly crisp. You can bump up the shutter speed some and still get a good shot, you'll just have a bit shallower DOF because of the larger aperture. Don't be afraid to use your flash for indoor shots like this - you can increase your shutter speed to something like 1/200 sec without increasing your ISO. If you're finding the reflections on the snake to be too harsh, you can use a piece of white tissue paper as a diffuser.

Also, in the first shot it looks like you are focusing on the tip of the python's nose rather than the eye... That will affect how sharp the image appears as well, since you have a whole area that's pretty focused that's not falling on the animal at all. Hope this helps some.

Derrel · Jan 20, 2010

There is a free shareware (donations accepted) booklet entitled Focusing The View Camera at this link http://www.trenholm.org/hmmerk/FVC16.pdf

and the cover of it, and the illustrations on pages 3 and 4 show the situation you are working in: your subject, the snake, is basically a flat, disc-shaped object positioned on a table. You aim your camera downward at the snake, and a substantial portion of the depth of field is used in "air". The real need would be to have a camera in which the lens could be tilted forward, so that the top of the lens were closer to the snake, and the bottom edge of the lens were closer to the back of the camera. This is called "front standard tilt", and it allows the photographer to re-align the plane of depth of field. But, that can only be done with a tilt/shift lens, or a camera with what are called "Movements".

At close distances, like the ones you are shooting at, depth of field is already quite limited, and because the depth of field cannot be brought to bear on the disc-like snake's shape, you will need at least two stops smaller an aperture to get adequate depth of field than what you are using, and I dare say, probably four stops smaller an aperture would be required to get the snake really sharp-looking from front to back, at least at the angle you have the camera set up in relation to the snake. So, this means you are going to need a pretty small f/stop, something like f/16 or thereabouts I would estimate, to get the snake sharp all over, at the current camera angle. And that means you will need pretty strong light.

EDIT: Here is a quickie drawing I made, where you can see how the nearest parts of the snake are badly out of focus, and why the back parts of the snake are also outside the depth of field plane.

The white balance ought to be set before the snake is brought in, so that the out of camera JPEGs look "right". Boosting the ISO a notch or two might also work acceptably well, especially with a modern d-slr and an exposure that is generous, and not biased toward underexposure. And by notch, I mean full stop notches, like from 100 to 400 or from 200 to 800 being "two notches".

Dominantly · Jan 20, 2010

He'll just have to be careful with the D40 and the higher ISO's noise.

I do agree stopping down will help increase your sharpness, I would also suggest giving a shot at manually focusing.
I believe the 18-55 is sharpest at around f/8-f/11, and is a very good lens despite being a cheap plastic kit lens...