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brownegaz
28-05-2013, 12:27am
I have had my OMD for about nine months and love using it after stepping up from a point and shoot Canon.
I recently bought a 9-18mm f4.0-5.6 wide angle zoom lens for landscape photography etc, but I find it does not focus well in low light condtions
I would like to know if others are having the same problem or if there something Im doing wrong, I would like to be able to compare the 9-18 with the 12mm f2.0 prime if anyone here is using it.
Thanks for any suggestions

ricktas
28-05-2013, 6:22am
Low light focusing is not the bane of your gear. It is the bane of photographers in general. Most auto-focus systems work by locking onto contrasting parts of the scene. So things like clear blue sky, dark night sky etc prove difficult for many AF systems to locate and lock onto something for focus. So firstly, it is not your particular gear that is the cause. We all have had the same issues at times.

So how do we get round this limitation? Well I use one of two ways, I work with the AF system and find something in my scene that has a defined edge where one side is lighter/different to the other and use that to lock onto. Examples would be, the edge of a fluffy cloud in a mostly blue sky. The corner wall of a building, a street light in the night-time, that sort of thing. The second way is to use manual focus, and in the dark, even use live view and focus using the LCD screen. Ultimately there are ways around the camera focus hunting (what we call it when the AF just keeps looking but cannot lock on) and we each have to find what works for us in any given situation. AF is good, but it is not perfect and all we can do is work within the limitations of it, or switch to manual focus and do it ourselves.

Rattus79
28-05-2013, 8:36am
I use the live view method myself. Zoom in on the live view and get solid focus, then zoom out and shoot. This method works best on a tripod.

Rick touches on hyperfocal distances without actually mentioning the word.
I'm sure there is some hyperfocal information in the AP learning database, fail that, a quick google will suffice.

It's a bit scientific and can be difficult to wrap your head around, but it works regardless of light conditions.

ameerat42
28-05-2013, 8:42am
...but I find it does not focus well in low light condtions
I would like to know if others are having the same problem or if there something Im doing wrong, I would like to be able to compare the 9-18 with the 12mm f2.0 prime if anyone here is using it.
...

It is not a problem unless you let it be. It's just how things are. I do not KNOW about the prime you mentioned, but I would EXPECT it to focus better with
4X the light hitting the AF sensors. Else, advice as above about focusing.
Am.

brownegaz
28-05-2013, 5:55pm
Thanks for the replies I am on a steep learning curve so any feedback like this is appreciated

peterb666
28-05-2013, 9:18pm
It can be very difficult to focus the 9-18mm lens in negligible light - certainly, like all AF lenses, the AF won't work so DO use manual focus.

Next problem is that if you cannot see anything through the LCD/EVF, you are out of luck as there is no manual focus scale.

I did use the 9-18mm lens extensively on my Olympus E-P1 and E-P3 but rarely use it now since I have a SLR Magic Hypercine 12mm T1.6 which is a manual focus lens with a lovely focus scale on it. The SLR magic is a very different lens to the Olympus 12mm f/2 (which I also used for quite a while). Certainly the Olympus 12mm is the better lens and it has AF to boot and probably the best implementation of a manual focus ring on an AF lens. Image quality is top class too.

About the only problem with the 12mm lenses is that if you love the 9-18mm lens, the 12mm lens just isn't wide enough.

- - - Updated - - -

Oh, one trick you can use with the 9-18mm lens and manual focus is to take advantage of the fly by wire nature of the AF.

Set the camera to manual focus and pre-focus the lens before it gets dark. When you power off, the lens will remain set to the same focus distance.

When you set up for your low light photography, power on and make sure you don't touch the focus ring.

Obviously this won't help in all situations, especially if you need to refocus, but it does help a lot. Pay special attention to hyperfocal distances and stop down to ensure you have enough depth of field.

gaze
10-07-2013, 11:02pm
Shooting at 9mm using a M43 sensor at apertures smaller than f4, unless you have something in the very immediate foreground, I do not think you will have too much trouble getting a good focus, even if autofocus isn't working. The depth of field will be rather massive. I think if you carried a small torch, and lit up an area somewhere a few metres from you and focused on that, you would then have very little in the shot that wasn't in pretty good focus (except as I say, something in the VERY close foreground). Not all that scientific, but I with these sensors, the calculations of hyper focal distances are far less stringent than in a full frame SLR

MattNQ
10-07-2013, 11:50pm
Yup, that torch idea does work well :th3:. I've done that for pre-dawn seascapes. Use the torch to light up the rocks. Otherwise the 9-18 hunts like crazy unless you have a clearly defined edge of something in silhouette.
Just picked up a small 12v rechargeable Cree LED torch for very cheap - amazing range & can leave in the car on charge