What are the benefits of (expensive brand new) manual focus lenses? Why did you, for example, buy a manual focus Carl Zeiss 85/1.4 rather than an auto-focus Nikon 85/1.4? I'm not concerned with these two lenses in particular. I'm curious about the reasons for buying expensive brand new manual focus lenses in general.
I think the question boils down to: 1) why use a manual focus lens and 2) what are the features to look for when buying manual focus lens. I'd be interested in these answers too :)– KarelSep 2, 2010 at 14:40
Every lens is a compromise. I want to know what people look for in manual focus lenses that they don't find in auto focus lenses, i.e. which features they trade auto focus for. Eruditass brings up interesting points so I've accepted his/her answer. If other people have additional or different reasons for choosing auto focus lenses, I'm still interested in their opinions.– Jan GoyvaertsSep 8, 2010 at 12:25
While you can obviously manual focus with an autofocus lens, manual focus lenses are catered towards manual focus users. Some possibilities:
- Longer focus throw (Autofocus lenses typically have short focus throws in order to focus faster.)
- More distance markings or depth of field markings (DoF markings are particularly useful)
- Wider focus ring
- Better feel, such as smoother or more dampened and resistant focus ring.
- Higher quality grip
- Lower weight since there is no AF motor
- No chance of AF motor failing (which could lock up the focus ring on certain lenses)
In addition, it could have been bought for its optical quality, bokeh, size, weight, build, prestige of Zeiss, and other qualities not intrinsic to simply being a manual focus lens.
3Video also doesn't allow for autofocus; another good reason to use a manual focus lens. Sep 2, 2010 at 15:57
This comment was written in 2010; with the advent of Canon's new STM lenses, video & auto-focus are friendlier now, right? Jul 21, 2012 at 12:32
Because auto-focus doesn't work for what you do, or simply because you don't use it. Then you can get a better quality lens for the same money.
Auto-focus works fine when some part of the image is exactly in focus, but if you for example want to put the focus between two objects so that they end up at the front and back edge of the DOF, auto-focus is useless.
Easy to get one or three batteries sharp with autofocus, but not two:
Unless you autofocus on the floor inbetween :) One area I always use MF is landscapes. Thank goodness for DoF guides. Sep 3, 2010 at 1:00
Manual focus certainly has its uses. What I'm curious about is the particular reasons that make you use the phrase "better quality lens". Obviously this differs from lens to lens. I'm looking for questions to ask when shopping lenses rather than advice on a particular lens. Sep 8, 2010 at 12:32
Simply because usually* you would want to spend as much money as possible on the actual glass.
Usually* you would want the fastest lens, with the best glass. In this case you would lose the auto focus because:
a. the awesome glass you want doesn't come in AF
b. the same awesome lens with AF is just too expensive.
Not all lenses are made equal, you just can't judge a lens solely by it's specifications.
*I say "usually because obviously different people have different priorities.
Don't forget that not all DSLR cameras are easy to use with manual focusing. Semi-professional cameras have dimmer viewfinder making the manual focusing process almost impossible, because you can't be sure you've focused right.
This doesn't really answer the question. But yes, the dimmer viewfinder will hinder but certainly not make it "almost impossible." There is AF-confirm, trap-AF, distance markings, DoF guides. LiveView with magnification also makes it incredibly easy with static scenes. Then there are split-image focus screens and viewfinder magnifiers, both quite popular with MFers. Sep 2, 2010 at 16:23
But a good warning for the guy not to throw away some money. BTW, do you know, for example, that AF-confirm on Canon 400D can miss for a half of DoF and it's okay for this cameras niche? So, AF-confirm on Canon 400D will NOT do any magic for you. So as a dim viewfinder. So, be careful before diving into manual focusing! Make sure your camera is from professional line (NOT from semi-professional) Sep 3, 2010 at 6:26