Old 02-16-2008, 12:12 PM   #1
MassArt Images
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Default Locomotive lighting and the problems it causes

Hi,

I've noticed that when shooting locos from the front, the ditch lights and cab lights can make the auto-focus freak-out and the exposure to vary. What tricks do you do with your camera to combat these problems without switching to manual focus and exposure? FYI - I am using a Pentax K100D.
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Old 02-16-2008, 12:18 PM   #2
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I think there was a discussion about this a little while ago, but try composing the shot before the train arrives and lock the exposure, so that when the train comes, the AF isn't thrown off. Maybe someone else can elaborate.
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Old 02-16-2008, 01:49 PM   #3
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Quote:
Originally Posted by Peter MacCauley
I think there was a discussion about this a little while ago,
I found the old thread. I went into detail about how I shoot my photos, however I do everything in manual. There are a few others who discuss how they prevent focusing problems as well. Hope this helps.

http://forums.railpictures.net/showt...3&page=1&pp=25
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Old 02-16-2008, 03:56 PM   #4
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Quote:
Originally Posted by Peter MacCauley
I think there was a discussion about this a little while ago, but try composing the shot before the train arrives and lock the exposure, so that when the train comes, the AF isn't thrown off. Maybe someone else can elaborate.
I understand how locking the exposure keeps the exposure from being ruined when a headlight shines right into the lens, that is why I do it, but how does that affect AF?
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Old 02-16-2008, 04:46 PM   #5
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Quote:
Originally Posted by JRMDC
I understand how locking the exposure keeps the exposure from being ruined when a headlight shines right into the lens, that is why I do it, but how does that affect AF?
Locking the exposure shouldn't affect the auto focus at all. With my D80 you lock the exposure by pushing one button and then to lock the AF you push the shutter release half way down. Once the AF is set it won't change unless you remove your finger and press it again. However, one of the AF modes on my camera has AF continually reset as you move the camera around or as objects move towards/away from you. Make sure your camera is not set to this setting when focusing on the front of the engine. The easiest way is to have the camera focus on something close to where you want the train to be in your photo, press the shutter release half way and then hold it until the train is where you want it. Sometimes when I've tried this though the AF will still get confused just before the train gets to where I want it, so if you have the time to learn it, I would suggest shooting in manual.
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Old 02-16-2008, 05:05 PM   #6
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I'm sure there's a way to set custom buttons, and with my Canon, I've set the * button to be the focus button. This way, I compose the shot, press the * to focus, remove my thumb and the camera is focused. Press the shutter only takes the photo; there's no focusing involved.

Bottom line, do what Wes said and have the camera focused before the train gets there whether it's pushing the shutter button halfway down or customizing a button. That way the lights on the train will not cause the AF to hunt...
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Old 02-16-2008, 11:22 PM   #7
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Quote:
Originally Posted by Ween
I'm sure there's a way to set custom buttons, and with my Canon, I've set the * button to be the focus button. This way, I compose the shot, press the * to focus, remove my thumb and the camera is focused. Press the shutter only takes the photo; there's no focusing involved.
That's how I have mine set up, too. Then I just point at the plow or track in front of the train as it's approaching to set my focus. Sometimes the bright light does throw of my focus a little, but having the * set to focus, it makes it easy to quickly recover.
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Old 02-17-2008, 02:05 AM   #8
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Quote:
That's how I have mine set up, too. Then I just point at the plow or track in front of the train as it's approaching to set my focus. Sometimes the bright light does throw of my focus a little, but having the * set to focus, it makes it easy to quickly recover.
As do I. Thanks to Jim and Chris, I switched to this and it has really helped focusing. Before I could completely miss a train because my camera decided to focus at the wrong time. Now I focus first and shoot away.
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Old 02-17-2008, 05:30 AM   #9
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Quote:
Originally Posted by MassArt Images
Hi,

I've noticed that when shooting locos from the front, the ditch lights and cab lights can make the auto-focus freak-out and the exposure to vary. What tricks do you do with your camera to combat these problems without switching to manual focus and exposure? FYI - I am using a Pentax K100D.
Bracket your exposures...
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Old 02-17-2008, 11:48 AM   #10
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Both the Canon 30D and 350D have three AF settings, One-shot, Servo and Focus. When I was getting used to the 350D I did try out the various settings, but found that the only one that worked for me was One-shot, 100mph passenger trains confused the hell out of the Servo and Focus settings.
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Old 02-17-2008, 05:06 PM   #11
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The easiest way to avoid af errors is to slowly switch over to mf. I started off trying some rather mundane shots in manual and setting up and picking a point where I wanted the train to be when I snapped the picture. I could get the mf set to be roughly right for that spot and then as the train nears you can fine tune. The hardest part is training your brain to do several things at once. Cars on a road are a great thing to practice on as long as you have a place where you don't look too conscious. If you're the one making the call on the focus settings then you don't have to worry about the camera picking the wrong one.
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