Autofocus or Manual Focus?

[0ptics]

Hey everyone,

So I was wondering, do most of you guys use autofocus majority of the time when you're shooting or manual focus? I tend to use autofocus because its easier and faster for me. So I guess my question is why do people some people use manual focus rather than auto focus? What are the pros and cons of AF/MF and when should you use MF rather than AF?

Thanks
0ptics

 

[Bitter Jeweler]

It depends.

 

[Derrel]

With an autofocusing lens, AF is usually faster AND more accurate, due to the higher precision that a machine-based system can achieve, compared with a human attempting to use an AF lens that was really NOT designed for hand-focusing. Many AF lenses have very hair-trigger focusing ring action, especially beyond about five feet in distance, and with those lenses, achieving accurate focus repeatably and reliably is compromised on today's autofocus camera bodies. Today's AF cameras have viewfinder screens that are bright, clear, and which do NOT show the shallow depth of field of wide-aperture lenses; people who really want to do manual focusing usually rely more on cameras that were designed for manual focusing, and which have viewfinder screens that are coarser, and which show shallow depth of field, and which also have focusing aids such as a Fresnel-equipped screen with a central split-image rangefinder, often surrounded by a microprism ring or "doughnut". (Google for Nikon K-screen). Manual focusing can be done pretty well especially with longer lenses, and also under good lighting conditions.

 

[Josh66]

I mainly use one of three cameras. Two of them are manual focus only.

On the one that actually has auto-focus, I usually do use auto-focus. Except when I'm doing macro, I mainly use manual focus for that.

Pros and Cons? Manual focus is more accurate a lot of times (macro). But, depending on the camera, it can be difficult. Especially if you're trying to track a moving subject.

I find that generally, on cameras meant to be manually focused, it's very easy. The viewfinder and focusing screen are made to make it as easy as possible.

 

[Natalie]

I use autofocus 95% of the time, basically whenever I'm not doing true macro photography (1:1 magnification). As mentioned above, autofocus is generally faster, and it's much more accurate at least for me. I don't trust my own eyes looking through the viewfinder, and I'm justified in doing so - generally whenever I try to do manual focus, when I get the photo on to the computer I find that the focus is off somewhat, ruining what could have been a great shot.

I think focusing is like the one thing the camera does better than I do.

 

[Ocho_1]

I use autofocus 95% of the time, basically whenever I'm not doing true macro photography (1:1 magnification). As mentioned above, autofocus is generally faster, and it's much more accurate at least for me. I don't trust my own eyes looking through the viewfinder, and I'm justified in doing so - generally whenever I try to do manual focus, when I get the photo on to the computer I find that the focus is off somewhat, ruining what could have been a great shot.

I think focusing is like the one thing the camera does better than I do.

Yeah, even though I just started, I really don't trust my eyes to get the best focus. Think I'll stick to AF.

 

[0ptics]

Oh ok sounds good, thanks everyone for the help. Its just seems that most photographers would use MF since there's always an emphasis on doing everything manual than automatically and I wanted know why cause I tend to rely on AF for standard shots. But yaI understand why you'd use MF on macro, long exposure, very dark shots, and other more specific shots.

A ya I noticed when I first got my camera I was trying out MF and in the viewfinder the scene looked clear and in focus, but when I.opened the picture up on my computer...it came out quite blurry :S...

Alright thanks again for the help!
0ptics

 

[airgunr]

For general travel shots, family gatherings and the like I use autofocus. If I'm shooting macro, still life, water drops, etc. I use manual.

 

[DorkSterr]

For me Macro/night photography = manual. everything else auto.

 

[Rephargotohp]

The problem with Manual Focus these days is that there are no Manual Focus assists like there used to be in viewfinders (In the olden days) Split Prisms etc. so it's a little bit harder especially on distant subjects. (Live view does help)

I use AF just like I may use AV or TV shooting modes. When I know the camera will get it right, put it on Auto, When I know it will F it up, I go to manual

 

[Tigertail]

If there's time to set up the shot I like to use the screen and digitally zooming in on the area I want in focus. This is perfect for shallow DOF shots where the eyes of the subject need to be in focus. It's much easier and more precise than using the viewfinder and even the AF a lot of the time.

 

[KmH]

Auto focus is not a be-all-to-end-all solution. There are many circumstances where AF is not capable of working well.

I wonder if you have investigated how auto focus actually works? Do you know where in your D3100 auto focus happens?

 

[BigknockHawk]

My eyes are not what they used to be!! I typically use auto for most everything except photos where my subjects are stationary and fairly close.

 

[mjhoward]

Today's AF cameras have viewfinder screens that are bright, clear, and which do NOT show the shallow depth of field of wide-aperture lenses; people who really want to do manual focusing usually rely more on cameras that were designed for manual focusing, and which have viewfinder screens that are coarser, and which show shallow depth of field, and which also have focusing aids such as a Fresnel-equipped screen with a central split-image rangefinder, often surrounded by a microprism ring or "doughnut". (Google for Nikon K-screen). Manual focusing can be done pretty well especially with longer lenses, and also under good lighting conditions.

Derrel, have you any experience with the KatzEye focusing screens on your more modern bodies? They have the split and mircoprism you mentioned. I've had the thought of getting one of these for a little while now but never went through. Here's the link: KatzEye™ Optics - Custom Focusing Screens

For me Macro/night photography = manual. everything else auto.

This pretty much covers my usage between AF/MF.

 

[Derrel]

Derrel, have you any experience with the KatzEye focusing screens on your more modern bodies? They have the split and mircoprism you mentioned. I've had the thought of getting one of these for a little while now but never went through. Here's the link: KatzEye™ Optics - Custom Focusing Screens

No, I have not bought any of the KatzEye products, but I do know they are considered some of the better aftermarket focusing screens. Canon also has an aftermarket screen available for a reasonable figure. Beattie, makers of the original Beattie IntenScreen, also still have screens for sale for over 350 different cameras. Beattie Intenscreen® - reflexite.com/energy/us/en