Manual Focus?

[UFOBMX]

When to use and when not to use Manual Focus?

 

[ceejtank]

I never use it.

 

[Patrice]

Only time I use MF is when my lenses don't have AF or if I've mounted Af lenses on an older manual SLR or I'm using some extension tubes. In other words, only when I have to.

 

[480sparky41 40]

I use MF when I want the focus point at a certain distance.

 

[SCraig]

I use manual focus when autofocus won't do what I want.

 

[Mully]

I use it most of the time...but I do not do sports so for me it is easy

 

[bhop]

The only time I use MF is if my lenses are MF only. (older nikons, leica and other rangefinders, etc.)

Sometimes if your subject is far away the AF might focus on something that's closer.. say.. shooting through a fence (not ideal, but sometimes you might need to) then manual focus might be the only way to get it.

 

[deeky]

I like having the control of manual, so I use it most of the time unless I'm shooting around with the kids or something. Allows me to put the point of focus where I want it for sure.

 

[greybeard35 7]

I use manual focus 100% of the time when I do macro work. I use AF to get it close and then touch it up manually.

 

[JMorris271]

I can put my point of focus where ever I choose in the wide area focus mode.

 

[Josh66]

Some cameras I have are manual focus only, so obviously I use it all the time on those. On everything else, I pretty much only use it if it's too dark for AF, or if AF is just acting weird...

 

[TCampbell]

There are a few times I use manual focus:

In very dark situations, the auto-focus often wont work because the camera needs enough light to focus. If you're in focus-priority mode (the default mode on most cameras) then the camera wont take the shot unless it can confirm that it locked focus. You can either (a) use a flash (many flashes have a "focus assist" beam which helps the camera lock focus) or (b) switch to manual focus and zone-focus the camera.

To zone focus, you pick a focused distance and adequate depth-of-field. Pre-focus the lens to your focused distance. Stand at the right distance, frame and shoot. As long as your DoF was adequate to account for the fact that you didn't really do an accurate focus, you'll still get a good shot.

I do have one tilt-shift lens. There's no such thing as a tilt-shift lens with auto-focus. When I use that lens, it's manual only (also, because of the way tilt works, it really wouldn't make sense to *try* to auto-focus a tilt-shift lens.)

Manual focus is harder with modern DSLRs than it was with manual-focus 35mm cameras. 35mm cameras usually had split-prism focusing so you could see (through the viewfinder) when focus was correct because of the split-image (when the two halves of the split image were aligned, you were focused.) Modern cameras assume the lens can auto-focus so there's no visual focus aids. You can replace the focusing screen on some DSLR cameras to get screens which work much better with manual focus.

It's particularly challenging with an APS-C DSLR because the mirror and image size is much smaller than it is in a full-frame camera. The viewfinder is smaller and may not be as bright as it is in a full-frame DSLR. For this reason, if you *can* use auto-focus, then it's preferred because the computer will probably do a better job than your eye.

 

[BeachDesign]

Always use manual, autofocus takes a lot out of the photography in my opinion.

 

[bratkinson]

As mentioned in various ways above, I use MF when I have to...ie, when AF doesn't focus where I want it to.

Understanding the "way" the camera decides on what to autofocus on is critical, as is choosing the correct autofocus points the camera should use. For Canon users, AF will typically select the closest subject that falls within the selected (available) focus points. Most times, I select center point only as the autofocus point to use. That way I tell the camera what to focus on, rather than letting it choose from more than one possible points. Other times, especially when I want something not in the center of the frame focused on, I'll let the camera choose from 9 or more (5D3 has 61 AF points). Recognize that for moving subjects (people, cars, etc), the ability to keep focus lock is far better done by the camera than by a human.

As mentioned above, shooting through a fence would confuse the AF, as does trying to focus on someone in a crowd, not in the one of the available focus points, or, the camera simply focuses on the wrong person. Then it's time for MF. I sometimes use MF when shooting items I'm selling on ebay when the AF just won't pick what I want to focus on. I also switch to Live View and focus from there, since I don't have any urgency to get "the shot".

Although I'm a former 35mm shooter and accustomed to manual focus, these days, I let the camera do the work 99% of the time.

 

[Solarflare]

MF with an entry level DSLR like my D5100 is a total pain.

- The viewfinder is very small and quite dark, giving little chances to see if something is in focus
- The viewfinder has no help for MF except through the AF confirmation, which is of no use if I use MF because the AF isnt working
- The manual focus ring of my 18-55mm and 55-200mm lenses is a pain in both instances; these rings are very wobbly and unreliable.
- The 35mm is much better, though. I can open it more, so I can see focus better, and the focus ring is okay. I still have to step down to like f/8 to reliably get focus. At f1.8, out of focus is pretty much guaranteed. I simply cant see that well whats in focus in the viewfinder.