Missed focus but it looked correct in view finder - with photo example

[Parker219]

On a manual focus lens, how do you know if you missed the focus because you moved at the last second, your eyes are off, or it was the lens fault? By the lens fault, I mean, is there anyway it can look in focus through the view finder, but NOT be in focus on that actual photo?

I can see on this photo the focus in on the leaf under the butterfly...

 

[Derrel]

Yeah...it can happen. Especially at close distances, like this shot was made at. Lens fault could be focus shift; some lenses, especially at close distances have what is called focus shift, where the focus point actually shifts from the wide-open aperture to the taking aperture, and even a little bit of focus shift at close range like this could mess up a shot. Also, there is the human factor too...moving the body a bit, mis-seeing the point of best focus, etc.. One summer I shot a TON of butterfly shots, and let me tell you...missed focus is extremely common.

 

[The_Traveler]

Look at the DOF.
too easy just to sway a bit and be outside the field.

 

[Parker219]

^ I don't really understand that chart. Does that chart have the numbers specifically for my photo?

What is the main thing I should notice in this chart...the fact that the total DOF is only .18 feet or I guess that is an inch or so?

 

[Designer]

^ I don't really understand that chart. Does that chart have the numbers specifically for my photo?

What is the main thing I should notice in this chart...the fact that the total DOF is only .18 feet or I guess that is an inch or so?

Unlikely. You would enter the correct figures for the variables to find your calculated DOF.

As to 0.18 feet, that is actually 2.16 inches. Still not very deep. In approx. 2 inches you would expect to see about one flower and the butterfly in good focus, but the other flowers would be OOF.

 

[Parker219]

Looking through the view finder, I thought my focus point was on the butterflies face. Thats what looked to be the sharpest point when I took the photo.

 

[KmH]

Higher end DSLRs have a DoF preview button that stops the lens down to the aperture the camera/lens is set to.
Using the DoF preview lets you see where the DoF is in the frame.
Focus is done with the lens open as wide as it will go so the viewfinder image is as bright as possible.

 

[Designer]

Looking through the view finder, I thought my focus point was on the butterflies face. Thats what looked to be the sharpest point when I took the photo.

If your camera focused automatically, you could turn on the focus area indicator to see where it focused.

 

[Parker219]

Looking through the view finder, I thought my focus point was on the butterflies face. Thats what looked to be the sharpest point when I took the photo.

If your camera focused automatically, you could turn on the focus area indicator to see where it focused.

This Tokina 100mm 2. D macro is a manual focus only lens.

 

[GlennT]

Have you used/checked the diopter adjustment? I've always had to adjust that to get the viewfinder in focus (the little dial on the viewfinder.)

 

[The_Traveler]

There are several things that could have happened.

• things seen through viewfinder are really small - and a bit difficult to see well what exactly is in focus. A dark object, like the head, will have a lot of contrast against a bright background and so the contrast may mimic focus.
  
• you may have swayed forward a bit and so too much of the field is behind where you were focused when you pressed the shutter.
• the camera/lens may be back-focusing

focus using live view and see how that works
try testing the focus with the camera on a tripod.
try shooting with higher f stop thus greater depth of field
learn to use the online depth of field calculator

 

[Derrel]

Modern d-slr viewfinder screens do NOT show the wide-open depth of field of fast lenses, as did older viewfinder screens. As Canon's Chuck Westfall noted, f/4.8 is about where the new viewfinder screens are set, in terms of the visible depth of field that is seen by the user when he or she uses the viewfinder screen. Meaning, with wider-aperture lenses, the view as-seen by the eye is not the shallow DOF of f/1.8 or f/2 or f/2.8, but that of a much smaller aperture. This is an absolutely HUGE problem with longer, fast lenses that are manually focused.

The viewfinder's brightness in some newer d-slr cameras is artificially brightened, using the camera's battery system; on some cameras, when the battery is removed, the viewfinder image darkens noticeably. This leads to a brighter viewfinder image with the dog-slow consumer zooms, the f/3.5~5.6 zooms for example, and since the focusing is done by an AF system, there's not much penalty.

A really easy test is to mount the camera on a tripod,m with a fast f/2.8 to f/1.4 lens on the camera; look through the camera focused on an outdoor scene, then press the DOF lever or button with the lens set to wide-open, then progressively stopped down in 1/3 EV increments, and see that the "wide-open" DOF rendering is...the same as it looks at f/4.5 or f/4.8.

If you want to do a lot of critical manual focusing with a modern d-slr, it's best to be aware that the through-the-lens viewfinder screen that is installed at the factory is NOT the best way to focus manually. Compared against older, 35mm manual focusing cameras, the viewfinder screens in d-slrs are a real bugger to use for critical manual focusing.

 

[Dave442]

The Tokina lens I know is autofocus, but only on the Nikon bodies with the focus motor. With butterflies I usually use autofocus or I prefocus on a point and then move back and forth a bit when a butterfly lands. Most autofocus cameras have screens that are hard to manually focus on, some have better help indicators to show when focus is achieved. I usually just have to take a lot of shots to really get the eyes in focus, but will usually at least have a wing or the body in focus. Try focusing work first on a non-moving subject.

 

[The_Traveler]

The Tokina lens I know is autofocus, but only on the Nikon bodies with the focus motor. With butterflies I usually use autofocus or I prefocus on a point and then move back and forth a bit when a butterfly lands. Most autofocus cameras have screens that are hard to manually focus on, some have better help indicators to show when focus is achieved. I usually just have to take a lot of shots to really get the eyes in focus, but will usually at least have a wing or the body in focus. Try focusing work first on a non-moving subject.

Best advice.

 

[astroNikon]

I use AF outside, as butterflies move and so do the flowers they land on (wind, breeze will move it). So if you are too close with too small DOF it's bound to be OOF.

to test ManualFocus you have to do it inside with a tripod on something that is not moving (or make sure nothing is moving especially if you are testing a shallow DOF).

last time I tried to MF /macro outside on a spider on a spiderweb, the wind was slightly blowing and it was moving up/down .. it was coming in/out of focus continually. AF from now on.