Question on DoF and focusing

[SuitcaseYogi]

Attached is a photo I took (Minolta X-370), in which I intended to capture the coffee cup in the foreground in focus, and give everything else a shallow depth of field. However, the opposite happened. The largest aperture on this lens is f/3.5, but anything larger is not necessary for the photos I generally take. Mind you, I have spent only a week with this camera and film photography as a whole.

My question is regarding the focus. Is the split-image circle guide in the center of the focusing screen supposed to be directly on the subject that is to be in focus, or elsewhere? I had it right in the middle of the foreground coffee cup, but it blurred it out and gave focus to the background. What am I doing wrong?

 

[SCraig]

Depth of field is an approximate distance from the POINT OF FOCUS, and is split between foreground and background. The center of the view is normally the point of focus with a split-image viewscreen. Looks to me like you either missed the focus or moved the point of focus after focusing. It looks to me like the point of focus is on the table behind the foreground coffee cup.

 

[Mike_E]

Were you within minimum focusing distance?

The image within the split screen is the one that shows the focus point.

 

[SuitcaseYogi]

Were you within minimum focusing distance?

The image within the split screen is the one that shows the focus point.

I was no more than a foot in front of it and had focused in manually, just a little bit. I was likely too close (physically), yeah?

 

[Mike_E]

Were you within minimum focusing distance?

The image within the split screen is the one that shows the focus point.

I was no more than a foot in front of it and had focused in manually, just a little bit. I was likely too close (physically), yeah?

Sounds like it. Take a look at the distance scale on your lens to verify.

Enjoy the Minolta!

 

[SuitcaseYogi]

Okay, I'll try to be more aware of that in the future. Thank you!

 

[Mike_E]

You're welcome.

Don't be a stranger.

 

[SCraig]

At f/3.5 and less than a foot away tour depth of field was virtually nothing. Probably an inch or so on each side of the focus point. Even the back cups aren't truly sharp but they are less out of focus than the foreground cup. I don't know what lens you were using, and a wide angle lens would have more depth of field (I assumed a 55mm lens).

When shooting that close you really need to use a tripod to insure that just moving your head doesn't take the subject out of the depth of field. You can also focus and then slowly move your head back and forth slightly until the subject is in focus and immediately trip the shutter.

 

[amolitor]

With manual focus lenses, it doesn't matter where the focusing aid (the center thing in the middle) is pointing.

The focus aid helps you get the lens precisely set to a specific distance, which is normally the subject. Put the split image disc on the subject, and focus until the two halves of the split image align perfectly. The lens is now set to so-and-so many inches, which is how far away the subject is RIGHT NOW. The distance the lens is set to isn't going to change. Wave the camera around wildly, point it anywhere - still the same so-and-so many inches. Inlcuding when you do this next step:

What you want to do now is compose your shot, WITHOUT changing the distance between the camera and the subject.

The lens distance setting doesn't change unless you turned it, in which case you're an idiot, and you need to go back to the first step! The subject is still the same distance away, because you're careful about that, right? So the subject is still in focus.

Now go CLICK.

 

[Derrel]

Were you within minimum focusing distance?

The image within the split screen is the one that shows the focus point.

I was no more than a foot in front of it and had focused in manually, just a little bit. I was likely too close (physically), yeah?

Yes, experience would indicate that was far too close to get much in-focus, especially at the lens aperture used. At such CLOSE distances, the lens aperture value MUST be set to the SMALLEST aperture size, which is usually f/22 or f/16.The split-image rangefinder helps you to determine the exact point of focus; the size of the lens aperture regulates how little, or how much, depth of field there is. Again, with a 35mm film camera, at such ranges, getting ENOUGH Depth of Field to pull all of that scene into acceptably sharp focus, with that lens, would be an extreme challenge. Decades of experience tells me that if you had BACKED UP about two feet, and shifted the focus point a bit, that you could have pulled the near AND the far two coffee cups into acceptable focus at f/16...with that lens...BUT, only from a little bit farther back!

DOF increases VERY rapidly as distance from camera-to-subject increases.

 

[SuitcaseYogi]

Alright. Thank you so much for your thoughtful responses.

 

[Paul Ron]

Focus the split image finder on exactly what you want in focus.