What to focus on?

[Quo Fan]

When I put the extension tubes on my camera, I get a really tight DOF for shooting flowers. My question is should I be focusing on the pistils, or the petals?

Here is a shot of the pistils.


Closeup of a similar flower, with out the tubes.

[Jacob6176]

I think that really depends on what your vision of the shot is. Some will want petals, some will want pistols, but in the end you are the one taking the shot so it is you that needs to decide what you want to get out of the picture.

[PhotoNewt]

The classic wisdom is to focus on the pistils of a flower, but is really up to what you want to highlight.

What an extension tube will do is to bring the lens farther away from the focal plane of the camera allowing for closer focus and larger magnification. The closer a lens gets to the subject the smaller the DOF will become.

On MACRO photography the DOF is quite thin and sharp focusing is critical. For that reason is advisable to use higher apertures (f/11 to f/22) to get the maximum DOF possible. After f/16 you are going to experience incremental defraction which will make your focus soft, you need to decide if this is an effect you like. Take multiple shots at incremental aperture values and then decide which you like best.

Manual focusing and exposure are highly recommended for this kind of work, a tripod is mandatory. In your camera set the mirror lock on the function menu to "engaged", then use either the self-timer function or a cable release to eliminate possible camera shake from manually depressing the shutter button.

Hope this helps.

P.S. Remember to "disengage" the mirror lock function after you are done shooting macro, it may not work well for general photography.

[Digidave]

Either way is a good shot. They both will have a different feel to them. You just have to decide before you set-up for the shot. If you get a shot that neither is in focus, toss it. You have to have one or the other in focus or it just doesn't work.

[HockeyFan]

Just take both shots and I think you'll appreciate both.

[PhotoNewt]

To illustrate my point, here is a close up of a flower I photographed a couple of weeks ago from a flower arrangement.

Canon 40D, 60mm, f/32, 10 sec, ISO 100 (manual exposure and focus)

Light source was difussed afternoon daylight through a window with a large white reflector on the opposite side; white balance was set to 6300K to enhance the yellow colors. Camera was secured on a tripod, mirror lock engaged and self-timer used to take the photo.

On this photo I wanted everything to be in sharp focus, that is why the small aperture. On a similar shot I used f/16 and the green leaves were nicely blurred but so were the flower petals.

[Quo Fan]

When I put my tubes on, it forces the lens wide open, I have no control on f-stop, and the longer the tube, the tighter the DOF. I use my Promaster 28-80 zoom lens as my "tubes" lens because it stopped playing nice with my camera, and I was loosing shots.

I was just curious as to what the "conventional wisdom" is.

[PhotoNewt]

Originally Posted by Quo Fan

When I put my tubes on, it forces the lens wide open, I have no control on f-stop, and the longer the tube, the tighter the DOF. I use my Promaster 28-80 zoom lens as my "tubes" lens because it stopped playing nice with my camera, and I was loosing shots.

I was just curious as to what the "conventional wisdom" is.

This is unusual, when I used tubes with my film and digital bodies I had complete control of both aperture and shutter speed; the autofocus function did not work well but manual focus is better for this anyway.

You said your 28-80 zoom "stopped playing nice" with the camera, is it defective? Does the lens performs normally without the tube adapter? What other lenses do you have?

[Quo Fan]

With my Promaster lens, I get a code 99 error, which is that the lens and body aren't communicating well. This is no big deal, because I have other lenses that are better.

My tubes are just tubular metal with lens mounts that only cost me $20 on ebay, so I'm very happy with them.

Tubes linky

[snap happy]

I love the look of macro being macro focusing on the minutest detail in the picture I often have to wipe the pollen from my lens. So I guess I would always focus on the stamen etc.