jerrypoller Loc: Huntington, NY

My grandson found a praying mantis in the yard a short while ago and I thought I'd try and get a few shots of it before it disappeared. I've never done any macro work but thought I'd give it a fast try. I used my D610 with a Nikon 35-70 f/2.8, handheld. I am set for a single focus point/continuous focus, and held the head of the mantis right in the focus box. It appears to me, though, that the sharpest focus is always somewhere else. Is it my imagination or is it possible that the lens focuses somewhere other than on the single spot in the viewfinder? I'm not terribly concerned with sharpness overall, but in what appears to me to be the "drift" in focus from my single focal point of hold. Any ideas? Thanks.

(Download)


(Download)

Rongnongno Loc: FL

Everytime you use auto focus while in macro you run into trouble. This is what you have.

Use manual focus and trigger only when you have the subject in focus (move slightly back and forth). You can also use burst mode.

Note that there experts on this subject in the macro forum.

jerrypoller Loc: Huntington, NY

I should have been clearer in my post - I used the term "macro" too loosely. I had the lens set to 70mm and wasn't using the "macro manual" focus feature of the 35mm focal length. I found that it required me to get too close to the critter for his comfort and he wouldn't hold still. So, I backed off and shot at 70mm, then cropped to the tight shots I posted. Sorry for the confusion I may have caused.

Nikonian72 Loc: Chico CA

The dead-center section of images #1 & #3 are in focus, but not the mantis head, which is outside of the images DoF.
I use A-F for all of my macro-photography, and close-up photography like these captures. I will focus on insect or animal eye (half-press shutter button), then recompose before tasking photo (full press on button).
Exif info image #1:
Camera Model: NIKON D610
Lens: AF Zoom-Nikkor 35-70mm f/2.8D
Image Date: 2015-09-18
Focal Length: 70mm
Aperture: ƒ/8.0
Exposure Time: 0.0040 s (1/250-sec)
ISO equiv: 100
Exposure Bias: none
Metering Mode: Center Weight
Exposure: Manual
Exposure Mode: Manual
White Balance: Auto
Flash Fired: No

jerrypoller Loc: Huntington, NY

I agree, the dead center of the image is in focus, but it wasn't dead center in the viewfinder when I shot the pic. I cropped the original to get the body centered - I didn't focus and then recompose the frame in camera. My single focus square was on the head when I shot the pic. And at f8 I figured the entire mantis would be in focus. I did the same for all 3 photos.

Nikonian72 Loc: Chico CA

If you want valid input about this situation, please post ORIGINAL images.

rdmesser2 Loc: Central Florida

Try switching to AFA and see if your focus point will stay in one place, AFC will follow movement and will change as you move or your subject moves. I shoot portraits for a living and always use AFA and focus on the eyes If you keep the shutter half depressed you can recompose. Also you might turn the beep on so that the camera tells you when it is in focus, sometimes if you let a little pressure of the shutter halfway it will refocus. You might also try BBF as this will hold focus until you depress the shutter and then refocus or just refocus with the BB.

jerrypoller Loc: Huntington, NY

I do use BBF, but not AFA. I'll make a point to reset my AF before I try this again. Thanks.

jerrypoller Loc: Huntington, NY

Point taken.

(Download)


(Download)


(Download)

nekon Loc: Carterton, New Zealand

Did you adjust the dioptre? (little wheel/slider next to viewfinder} Disconnect lens , point camera at a light neutral source and set dioptre to bring focus point into sharp focus-replace lens-I should explain with lens attached it becomes harder to concentrate on Just focus points.

leftyD500 Loc: Ocala, Florida

Curious Nekon...what does the diopter have to do with focus of the camera? I thought the diopter is for adjusting what you see in the view finder.

nekon Loc: Carterton, New Zealand

If you are using autofocus, it matters. The viewfinder sees what the lens sees.

Brucej67 Loc: Cary, NC

One point to remember is the closer you get to your subject (with any lens) the shallower your depth of field will be, and this holds true for close in shots like this.

jerrypoller Loc: Huntington, NY

Thanks - that should have been obvious to me, but wasn't. Is there an optimum aperture setting then to assure about 2-3 inches of sharp focus?

Apaflo Loc: Anchorage, Alaska

It might be astounding that you got as close with focus as you did!

First, read page 98 in the User Manual. It explains when AF will work best, and when it may have trouble. Every image you posted fits a scenario that will be a problem. Too much detail at different distances, forcing the AF system to try picking which is most prominent, and that might be different than what your brain will see when looking at the same thing. In this case there is no good answer. Probably the main "cure" is to shoot a lot of images. Who cares if 9 out of 10 don't get it right!

But there are some issues with how AF should be configured. Do NOT use AF-Area and do NOT expect any value to be achieved by adjusting the diopter.

Go to page 221 in the manual. Set registers A1 and A2 both to "Focus priority".

Take your pick on using AF-S or AF-C, but in this case I would use AF-C if you are handholding and AF-S on a tripod. AF-C will follow your movement, AF-S will not.

You were correct to accept the fact that you will need to crop, but perhaps there are ways take more advantage of that.

For those shots, you could have stopped down to f/16 or even better f/22 (use of proper sharpening will remove blur from diffraction, probably even up to f/32). That will give you much better DOF. And with a relatively wide angle lens you can shoot at a slower shutter speed if necessary, but try a higher ISO first (up to ISO 800 it won't make any difference at all). Check the histogram to verify your exposure.

If you choose to use Auto Focus, just basically fire away aiming at the part of the subject that is most likely to let the AF system work. With a DOF greater than the depth of the entire subject, it won't be so critical. Frame as you like later when editing.

If you choose to use Manual Focus you want to effectively bracket focus. If you aren't extremely steady that is going to happen no matter what you do! If you are leaning on a support you might want to purposely introduce some focus depth variation.

In all cases there is no point in shooting 10 or 20 shots when 100 would be just as easy.