I am looking into getting a Nikon soon (either a D3100 or a D5100). One of the reasons that I am upgrading from a point and shoot is because I want to have more control over the camera's functions. In particular, I want to be able to manually focus. As I shop for lenses, are there any lenses that don't allow for manual focus? Is there anything else I should look out for on this front?
If there are, I've never seen one.
They do not offer the same comfort for focusing. On cheap lenses, I noticed you have to turn the front element to focus which does not give much grip and also rotated the front element which is not good if you have a polarize filter.
Better lenses have a nice texture focus ring to let you easily change focus. There is also something called the throw distance which is how much you have to turn to focus. If it takes more distance to change focus than you can focus more precisely. This is often how macro lenses work.
The other nice thing is to have quick-shift focus (maybe called something not the same for different brands). This allows you to focus manually without switching to manual focus mode! You just turn the ring and it works. I find we can search for lenses with that feature for Nikon for example.
I am aware of three Canon EF lenses that are autofocus-only--they are the only such lenses that can directly fit a DSLR (without adapters):
I do not know of any AF-only lenses from any other system, except, perhaps, the obscure autofocus Olympus OM-system lenses (which did allow focus by wire controlled by the camera body, if the body supported AF; they were unusable on manual OM bodies).
In short, there are no Nikon lenses that are AF-only. However, some lenses lend themselves better to manual focus, while other lenses have thin focus rings, short focus ring travel, and no distance scales--these are usually inexpensive lenses that are optimized for autofocus with manual focus provided as a fallback rather than a usual mode of operation.
I don't think any lens prevents you from doing so, but without a special focusing screen, this is very difficult to do accurately and fast in a DSLR. See Can manual focus be faster than autofocus? and When is manual focus better than autofocus? The more likely case is that when purchasing Nikon bodies and lenses, you have to be worried about getting Autofocus.
- All the lenses should be able to manually focus.
- Some old Nikon lenses are just manual focus.
- Newer ones have a switch on the lens M/AF.
- MF/AF can also be controlled by the camera. By setting the AF mode to manual.
Now I’m not sure if the models you mentioned offer camera override, but visiting Nikon website and checking out the specifications should answer that question.
Hope that helps,
All (nearly all?) lenses designed for modern DSLRs have a switch that can turn off auto-focus and enable manual focus.
However, some lenses work better with manual focus than others. I don't know what the Nikon term for it is, but Canon shooters talk about full manual over-ride, where you can just twist the focus ring and the lens will stay at that position. This can be down with the auto-focus still on. On other lenses, the auto-focus mechanism will try to correct your manual focus -- this gets to be a pain.
Most DSLRs do not expect you to use manual focus, and so they have focus screens in their pentaprisms that don't help you. This is in stark contrast to the way focus screens were back in the film days. You need a microprism, or split screen or other screen to help you see when things snap into focus.
Make sure that the body you buy allows for easy changing of the focus screen, and add in the cost of a good manual-focus screen to your budget.