How to do Portraits of Flowers

 

Nikon Z 70-180 @ 170mm and f/8

This will be a short one. I only want to share one tip with you that I almost forgot. I might have mentioned it a few times here, but I think it is worthwhile to repeat.

As a matter of fact, the depth of field (DOF) at a given aperture will stay almost the same if you change the focal length, but keep the subject at the same size in your frame. E.g., doing a head portrait with a 50mm, 85mm, 135mm or 200mm at f/4 yields the same areas of sharpness. Of course, you have to change the distance. The 200mm needs quite a large distance for a head, by the way.

What changes dramatically, is the background. A 200mm lens will show only 1/4 of the background in each dimension compared to 50mm, and it will deliver a 4-times smoother background. The background can also be easier selected to avoid distracting elements. We usually want that for beauty shots, and it's one reason why long lenses are used for portraits. The other reason is that they deliver less distortion and the face looks more elegant.

For flowers and objects of similar size, long lenses are the way to go. Even an expensive 105mm f/2.8 macro lens is not long enough. And the lens does not have to be f/2.8 too. Just take above 150mm and f/8.

I have bought the Nikon Z 105 f/2.8 MC VR last year. It is a true macro lens allowing a 1:1 magnification, and maybe a bit more with macro rings. But it turns out that I rarely do macros. I used this lens for other photos. This is not the worst idea, because the 105 MC is a truely excellent lens. But is it really necessary if you are not diving into the small macro world?

Here is a comparison for smaller object.

These two images have been taken with the 105mm MC f/2.8 and the 70-180mm f/2.8, both at f/16. Because the subject is small, I had to crop in the 70-180mm to approximately 360mm. Because of this and the enormous quality of the 105mm macro lens, the details in the macro shot are more punchy and crisp. But you might not even notice on the monitor or normal print sizes. And a different processing can easily spoil the image quality.

Here is another example, taken with the 70-180. By the way, the colors of these roses seem to be too much to take for my poor camera.

The next image is from the 105mm macro using f/8. It shows the outstanding sharpness and image quality of this lens. It also focusses fast which might be important for small animals. Moreover, you often do not have the distance for a longer lens. But, if you just own a relatively slow telephoto lens you can often achieve the same results.