Manual versus autofocus

[Robin]

Hi,
As a parallel question to Steve's on Sigma lenses, how many of you focus manually and how many use autofocus?
What are the pros and cons?
As you will guess from Steve's thread I use autofocus in single shot mode. The downside is that sometimes the initial focus takes a while, but after that I can snap away and the camera takes care of any small shifts in focal distance.
My camera is always on a tripod and wherever possible I use all 3 legs but sometimes just one like a monopod. I even find that holding the tripod tight against my body makes the camera more stable than just holding the camera on its own.
Any thoughts?
Robin

[Pete Eeles]

That's a great question (I have a Sigma 105mm).

I must admit, I tend to use autofocus for most field shots (where I generally don't use a tripod) although, as you say, sometimes the lens "misses" the target and takes an age to track back to the subject - time to lose the shot. But I do find that, in the field, autofocus is generally quicker than I am. Even if the subject is off-centre, I'll tend to autofocus on the subject, then reframe the shot. Even when using a tripod, I generally use autofocus.

However, there are occasions when I'll switch to manual - generally when autofocus doesn't focus on the subject!

Cheers,

- Pete

[Dave Mac]

I tend to use auto-focus because it takes a lot less time than focusing manually and sometimes you only get one fleeting chance of a picture. However some auto-focus lenses are a lot faster than others and a lot less prone to hunting which might effect the way you choose to use it. The only time when auto-focus falls over is when there is a fine blade of grass immediately in front of the subject or just slightly to one side, then the auto-focus will insist on focusing on the grass and not the subject. This can be avoided to some extent by using the centre focusing spot only, which is a lot more accurate than using the array of all of the spots.
Cheers
Dave

[Gruditch]

I use manual nearly all the time. Only when I'm trying to get a shot of a subject that will not settle for long, do I switch to Autofocus. I always use a monopod, I tried using a tripod but it drove me nuts.

Gruditch

[Chris]

manual focus AND a tripod! but I tend to do all my butterflying before the sun is above the tree-line. The Sigma 150mm does take ages to hunt if it misses first time.

[JKT]

Manual focus for all the macro shots. Too much axial movement for auto. Often I predict the correct timing from the viewfinder instead of shooting after seeing correct focus. A tripod might change things.

[Martin]

Manual...mainly because I use extention tubes which makes lenses "hunt".

Marrtin.

[Robin]

Perhaps I should have made this a poll. The manuals are leading 4:3 over the autos at the moment.

[Bryan H]

4:4, Robin!

Getting as close as I have to with a 105mm, I don't like the idea of making hand movements.

Bryan

[Rogerdodge]

I don't like the idea of making hand movements

This is exactly the point of using manual focus.
You do not have to touch the focus ring.
Here is my procedure.
I pre-focus on something the size of the creature I am hoping to photograph. (or use the magnification scale to set the focus - see later)
Then move the camera slowly towards it. As it starts to come into focus I pull off one or two shots, and then pull back again shooting one or two shots as the focus is achieved again. Don't forget that we are only talking millimetres here!
With practise it is easy(ish) to adjust the focus ring without even looking through the viewfinder depending on whether it is a Small Blue or a Swallowtail you are after.
e.g 1:1.5 is fine for Small Blue (on a Canon 1.6x crop), and 1:4 for the Swallowtail.
These give pretty much full-frame shots, adjust for arty stuff!
YMMV
HTH
Roger

[Chris Pickford]

Manual!

As well as the points made above, I find that the sounds of a/f may also spook some butterflies. I preset focus and move the camera forwards into focus, using either a Tamron SP90 (digital) or a Nikon Micro 60mm.

This summer, I chased a Black Veined White around a meadow (Loire) for half an hour with a/f, but found that with manual focus, it sat on a clover head and allowed me to take 8 or 9 images before flying off.

I have found a/f ok though for near-frozen butterflies - early am, or cold, wet, and roosting. My ability to focus is probably nowhere near as good as the camera's at that time of the morning......

[Malcolm Farrow]

Autofocus with occasional manual override (where I lock the focus and move the camera) for the rare occasions when the autofocus doesn't quite pick up the correct focus position or where the sensors don't align with the insect i'm shooting.

The Nikon 105mm VR AFS was quick and accurate with the D200, but it's simply wonderful with the D2xs - focusing is instantaneous and it practically never hunts. I find autofocus leaves me free to concentrate on framing and composing the image - it's quicker and seldom lets me down.

Best wishes

Malcolm

[Dave Mac]

It all depends on what you want to take snaps of. A stationary butterfly is fairly easy to photograph using manual focus, but to take a picture of a moving insect or bird gets a lot more difficult without autofocus. A good autofocus will track and adjust the focus as it moves.





Camera details: Canon 400D, lens Canon 300 zoom IS, 800 ISO, Aperture priority mode f5.6, centre point focus

Edit: I have just moved this as I originally posted it in the wrong thread
Cheers
Dave

[eccles]

If photographing a static subject, I prefer AF but contrary to Dave Mac I have got more keepers using manual focus for moving subjects, although it's early days yet with the dSLR.
Sony A100, Minolta 75-300 D zoom, iso800 F8, 50% crop

[Dave Mac]

Nice picture eccles, it beats me how you managed it
Cheers
Dave

[Jacqui Jay]

I tend to use aperture priority, as our weather can change so quickly, literally from minute to minute and time is of the essence when photographing butterflies, as we all know. It is relatively easy (and quick) to just spin the aperture wider or whatever and let the camera take care of the s/s.

[LCPete]

I mainly use auto focus for most things just find it easier to focus on the head then reframe.
But for close up stuff like small butterflies at about 1:1 I manual focus.
Pete