Achieving Perfect Focus at Night
SimplyShane
Registered Users Posts: 153 Major grins
First, before I say anything, I just want to thank you guys for being so generous with your comments. I joined this forum at the end of May, and already, I've received tons of help and suggestions. I'm grateful!
Now, on to the topic. I recently went out shooting at night on a lake, and I was sourly disappointed with the results. Though every shot looked great magnified at around 25 to 50%, at full-view, I discovered that a majority of my shots suffered from soft focus.
Now, I could post some images, but I don't think it's worth it. Why? Because there could be a million-in-one things that caused this issue, and discovering what exactly that was may just be a waste of time.
So, instead, I ask everyone here::: What is YOUR PROCESS? At night, how do you approach the issue of focusing your camera? I'd love a step-by-step explanation if anyone has the time. I've been doing my own research on this issue, and there are definitely things I can improve on already...
Before I go, however, I do want to ask one specific question:: Is Auto-Focus always a bad idea? If you have to manually focus, are there "smart" ways of going about it? (Live View??)
Thank you for your time.. ^_^
Now, on to the topic. I recently went out shooting at night on a lake, and I was sourly disappointed with the results. Though every shot looked great magnified at around 25 to 50%, at full-view, I discovered that a majority of my shots suffered from soft focus.
Now, I could post some images, but I don't think it's worth it. Why? Because there could be a million-in-one things that caused this issue, and discovering what exactly that was may just be a waste of time.
So, instead, I ask everyone here::: What is YOUR PROCESS? At night, how do you approach the issue of focusing your camera? I'd love a step-by-step explanation if anyone has the time. I've been doing my own research on this issue, and there are definitely things I can improve on already...
Before I go, however, I do want to ask one specific question:: Is Auto-Focus always a bad idea? If you have to manually focus, are there "smart" ways of going about it? (Live View??)
Thank you for your time.. ^_^
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if your body offers it, the best technique in the dark is manual focusing, careful attention to depth of field, and the use of live view to focus precisely. To really do this, you must be shooting from a tripod too.
Moderator of the Technique Forum and Finishing School on Dgrin
if you are shooting a night pano with out much light then manual focus is your friend. set the focus point at infinity and shoot way.
if you are shooting a night portrait then your on camera focus assist or focus assist beams on your hot shoe flash should do the trick.
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I'm using a Canon Rebel XS. Yes, it offers Live View.
Guess that's going to become my new best friend. :-P A pity that it wastes so much battery though...
http://www.flickr.com/photos/bengford
I know this is a very dumb question, but....
How does one "focus at infinity?" I've heard that said often... How do I do it?
Oh, and I'm mainly interested in landscapes.. (FYI).
http://www.flickr.com/photos/bengford
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I've used a few different techniques to focus to infinity. The best possible (at least for me) is if the lens has a marked focus ring. My Tamron 19-35mm wide angle has one, so I can flip over to manual focus and just dial it over to the infinity mark. Most of the less expensive lenses don't have one, not sure about the kit lens that came with the XS, but the 18-55 that came with my XTi doesn't have one. (In the image here on Amazon you can see the marked focus ring. This one is actually focused to infinity in the image.)
If you don't have one, turn your autofocus on and focus on a bright point of light in the distance. Either a far away street light or even a star. Once the lens achieves focus, flip it over to manual focus so it won't change and you should be good to go.
My XTi doesn't offer Liveview (:cry) so I can't really comment on the use of it, though I have heard that it's extremely awesome!
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As can be seen from the posts in this thread, there are several different ways of focusing in the dark, and it is good to be able to perform each of them them with ease and facility. Practice helps. Using a light source - torch, headlight, etc can be useful but if your are shooting in a group, may not make you very popular with the other shooters around you, since you may be ruining their shot if their shutter is open and they are exposing their film.
Most cameras have a light source for focusing in dim light for near subjects, but that won't help at infinity.
As a landscape photographer, one simple technique I use a lot, is to switch my lens to manual focus, rack it out to infinity, and then dial it back from infinity just the slightest amount - 1/8th in to 1/4 in of barrel rotation. Some lenses will focus past infinity, so you need to know where your lens really rotates at "infinity"
The original poster will want to read about hyperfocal distance, as well, so that they understand how to get the fore ground and the far background in focus - which is not focusing at infinity, but some middle distance between the subject and infinity - the hyperfocal distance.
Depth of field calculators can help with this a great deal. There are small programs for iPhone and Droids and iPads that make this very easy today. Google depth of field calculator and all these topics will pop right up. It is good to be aware the calculations of depth of field include some assumptions about viewing distance as discussed here
Here is an image focused in the dark by rotating to infinity and backing off just a touch - shot at f8 - The foreground was light painted, but I wanted the stars in focus and they are
Here is one where AF works - the moon is sunlit so AF will usually grab focus for you
[imgl]http://pathfinder.smugmug.com/Travel/Shootout-2008-Backroads-of/Moonrise-red-rock-MG8560/439256304_bVmXv-L.jpg[/imgl]
Here is one shot in the dead of night in the Utah desert - can you find the Big Dipper in all the stars?
[imgr]http://pathfinder.smugmug.com/Travel/Wild-Utah-N-Mexico-and-Arizona/Big-Dipper-over-Tomisch-Butte/682177732_v8zoF-XL.jpg[/imgr]
Moderator of the Technique Forum and Finishing School on Dgrin
For nightime infinity focus I practice during the day and watch to see where the focus ring hits infinity focus on a very distant subject. At night I use a small flashlight to help find the same mark in manual focus. When in doubt, bracket the focus.
P.S. Pathfinder's recommendation for using the Live View (when appropriate) is excellent.
Moderator of the Cameras and Accessories forums
Western burbs of Chicago
Moderator of the Technique Forum and Finishing School on Dgrin
Western burbs of Chicago
If I am using AF and I spot-focus, I would have to find an object twice as far away as the closest foreground object and focus on that, to set my hyperfocal point? Because I have been picking either foreground or background to focus on (AF or manual), then stopping the lens to adjust my DOF to get the rest of the picture either sharper or softer. But after reading about the hyperfocal point, I realized that I was using poor technique that probably caused less than desirable focus in many of my shots.
*Important update*
After spending much of the day researching this issue as well, I can safely say that nobody has come to a consensus over whether or not one really *needs* to learn about hyperfocal distance. (See this link:: http://photo.net/canon-eos-digital-camera-forum/00VMmm)
Reading that gave me a big headache and left me with no tangible answers.
The bottom line is this:: How do I get everything in acceptably sharp focus at night? (Considering my focus is landscape photography.)
That's really it folks. Apparently Live View is a savior in this regard. I may start using it heavily and just start experimenting with things. It seems the best thing to do.
http://www.flickr.com/photos/bengford
Of course it's important to understand the concepts of hyperfocal distance, DOF and circles of confusion. It is the "application" of these principles that allows you control of the range of relative sharpness in your images. There is no singular solution that works in all circumstances.
When in doubt, bracket your f-stop/shutter speed to allow variations in DOF while maintaining correct exposure. You may choose differently depending on the results when you view at distribution sizes.
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Thank you to the OP and others who have replied here!
Using Mirror Lockup (if your body has it) combined with a tripod is another way to ensure sharp focus...
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The focusing system is going to look for contrast. If the subject is so dark the focus lock light never comes on, I look for an object at the same distance I want (even if it's not the actual subject) that has the most contrast, if available, then I hit it with my center point and focus, then I turn off autofocus so it won't move.
If it's nearby, I'll light it up with something. As mentioned, if your flash reads the distance you can use it. I've used flashlights. Anything to generate enough contrast to lock focus.
If it's far away, I'll use the "read infinity on the lens scale, set it there, then back off" method mentioned above.
Also, verify that the blur you see is actually due to focus. Night shots need long exposures, so if you bump the tripod you could introduce blur. I don't have a remote, so I set the camera for 10 second self timer and get away from it to let any vibrations settle down before the exposure begins. I forgot about the mirror lockup thing, though, maybe the mirror still slapped the camera around...
Wow!
I wish I had been into photography when I lived out west.
Simple, just like Ansel did, lug about a big ol' honkin large format/view camera and f/64.
I wish I had the faintest of clues, sorry.
5D2/1D MkII N/40D and a couple bits of glass.