Close Up Of An Eye

[zkogut]

Took this picture while visiting home back in Upstate NY. This is my dads eye with my new macro lens. What do you think?

-Zak

[chauncey]

Your DOF is on the shallow side...lash reflection is crystal clear veins are not.

[Otavio]

Hi, Zak; I think this is a very good image that could benefit from the larger DoF, as Chauncey mentioned. Well done. Cheers,

[zkogut]

Thanks for the critique guys but I don't like to increase my dof past f/11 for these shots. It's not like the sliver of focus gets that much larger plus the veins don't add to the shot in my opinion.

[Clive Kirby]

I agree with Zak. I like the dof just as it is.

[Downrigger]

I like it as it is, too. Everything in focus would be clinically correct, but artistically less interesting. I think the subject works here as the iris and the reflections in the cornea. The softness around them helps make that more evident.

[DanK]

Very nice shot. It's all a matter of taste, but I would go for a greater DOF as well.

A couple of technical points about DOF in macro, an on-the-one-hand, on-the-other:

First, because of the way macro lenses work, the effective focal length and f/stop increase as magnification increases. This is explained in a tutorial on this site: https://www.cambridgeincolour.com/tu...cro-lenses.htm. I believe some Nikons register the effective f/stop. Canon cameras don't. That means that on Canon cameras, the effective f/stop is greater than the camera's setting, and diffraction sets in at a wider nominal aperture (lower f/stop) than it does at greater distances. This is on the one hand.

On the other hand, for many purposes, it doesn't matter much. Colin often posts that the effects of diffraction are overblown, and that has been my experience. If you are going to display on the web, it makes very little difference because the displayed image is so low in resolution. Even printing up to 8 x 10 (roughly 20 x 25 cm), it makes little difference unless the image has very fine detail. As an example, I will post below a photograph I took 5 years ago, soon after I started with macro. The camera was a nearly bottom of the line Rebel of that era (XTi), and the lens was an EF-S 60mm macro. I don't recall exactly, but the image is somewhere between 1:2 and 1:1. The aperture was f/20, and since this was a Canon, the effective aperture was substantially smaller (larger f/stop). I had this printed as an 8 x 10 for some time, and it looked just fine.

My bottom line is that I try to shoot macro at (nominal) f/13 or below, in part because I now print larger, and also just to play it safe. Also, I often stack images for greater DOF. Some of the macro photographers I know who are much better than I am do something similar. However, if you are not going to print large, and if the image does not have a lot of fine detail (such as the patterns in a bug's eye), a smaller aperture may sometimes yield a nicer overall effect (depending on what you are trying to get), appearing sharper overall because of the greater DOF.

[vaez]

interesting image

[zkogut]

Thanks for all the interesting info, Dan.