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02-09-2013, 03:25 AM   #1
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(Manual) Focusing in the dark

Hello,
I've recently bought a K-5 and the 50mm f1.4 manual focus to shoot in low light.
I'm quite happy about the lens, considering the overall quality and the price, but I have a real hard time with the manual focus when it's dark: it seems I just can't get it right.
I guess I'm not the first one experiencing this problem, what did you do to solve it?
(I wasn't able to find any thread talking about this, should there be any, please link it below)

Thanks,

Emiliano

02-09-2013, 05:08 AM   #2
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Manual focus can be really hard on DSLRs, because they were made mostly for AF. So the viewfinder is small, and the lenses have short focus throw and often without distance scales. With your lens you can try zone focusing or using the distance scales as an estimate. Liveview can also help you out a little. If you stop down the lens (to a higher f-number) you will get a thicker DoF, which increases your chances of getting things "in focus." At f1.4 the DoF is pretty thin, so its hard to nail the focus. You can buy and install a focusing screen, some people did that and are happy with it. Some people buy a viewfinder magnifier /loupe.
But I think the best thing is to keep practicing. You can also use AF and t hen manually adjust, especially if your lens has quickshift.
02-09-2013, 06:32 AM   #3
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Check your viewfinder for the octagon to illuminate or set the beep function to alert you when you are in focus. and practice
02-09-2013, 07:33 AM   #4
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get yourself a precision focusing screen made specifically for the K-5 and manual focusing. I think you can find it here
Focusing Screen

02-09-2013, 09:32 AM   #5
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Focus in low light is difficult even with a fast lens and excellent viewfinder/focus screen. I guess that may be why so many "club" shots are technically flawed . When shooting film, a rangefinder camera with bright viewfinder may have a small advantage...assuming that there an edge to work the focus patch on. The same is true, though to a lesser extent, for a split image focus screen in a dSLR.

The fall-back solution is to make your best guess with the matte portion of the focus screen. Ironically, the highly optimized screen that came in your camera is poorly suited for the task. It is bright, but the effective depth of field is equivalent to that of about f/4. A dimmer aftermarket screen may actually do a better job. Franky's link (above) will lead you to a reputable source for such.

A last solution is to use the distance scale on the lens. Vintage lenses typically have a more usable scale due to longer focus throw. They are also somewhat easier to manually focus due to that longer focus throw. The AF focus confirm is also useful, but in low light its performance is probably not as good as your eye.


Steve
02-09-2013, 09:42 AM   #6
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I use a split-prism screen and when it works, focus confirmation. Usually works pretty well.
02-09-2013, 10:40 AM   #7
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BTW...I should mention that I am a real fan of aftermarket screens for manual focus in general. A proper screen makes all the difference when using manual focus with fast glass.


Steve
02-09-2013, 11:31 AM   #8
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The stock screen is next to useless when using with MF lenses, especially with fast glass. I use a combination of KatzEye split prism with an O-ME53 viewfinder magnifier. When shooting with slow glass (mirror lens or lens + TC), I turn off the focus confirmation and rely solely on the split prism and/or the micro prisms to focus.

02-09-2013, 01:04 PM   #9
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I've been doing some night shots on a tripod with various DSLRs, and this is somewhat difficult. I've had some luck bringing a headlamp, shining the light on a subject, locking on with the AF, and then switching the AF and lamp off. Shots have been pretty sharp. Doesn't really help in low light indoor situations though where you have moving subjects. If the shots are in the distance, set the AF to infinity earlier in the day, then switch the AF off, and tape the focus ring. Folks do that here in Alaska for northern lights photography.
02-09-2013, 02:24 PM   #10
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QuoteOriginally posted by sb in ak Quote
I've been doing some night shots on a tripod with various DSLRs, and this is somewhat difficult. I've had some luck bringing a headlamp, shining the light on a subject, locking on with the AF, and then switching the AF and lamp off....
+1. A torch or head lamp can solve your problem.

Another option is to use the distance markings in your lens. If you know where you want to focus, set the MF ring to that distance. It may need some fine tuning because the distance on the MF ring might be slightly off the real distance, but this is something that you can easily calibrate/check yourself wth a measuring tape.

Hope that the comment may help.
02-09-2013, 03:29 PM   #11
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QuoteOriginally posted by emiliano Quote
Hello,
I've recently bought a K-5 and the 50mm f1.4 manual focus to shoot in low light.
I'm quite happy about the lens, considering the overall quality and the price, but I have a real hard time with the manual focus when it's dark: it seems I just can't get it right.
I guess I'm not the first one experiencing this problem, what did you do to solve it?
(I wasn't able to find any thread talking about this, should there be any, please link it below)

Thanks,

Emiliano

What are you calling dark? These old eyes have taken some decent shots using "catch in focus". Pure manual with the low quality screens in the k-2000 not so good.
02-09-2013, 10:26 PM   #12
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I was taking pics for a birthday party in a karaoke room and besides the tv and a disco ball light, there was hardly any light. The k5 would focus after the focus assist light came on, but that was very distracting and I quickly turned it off. So... I stopped the lens up as much as possible to increase the depth of field, took out my DOF calculator to see where the focus area was at given apertures, and just tried to get as close as possible. I had the cam on machine gun mode and would sometimes be turning the focus ring as I was shooting to kind of focus bracket. I was often shooting at iso 25600, f2.4 @ 1/60th so it was pretty dark. BUT.... I had wider lenses than 50mm and wider lenses have a larger DOF given an equal distance and aperture. So I went w/ my widest fast lens and cropped where I needed to in post. So if you have a decent fast zoom lens that is wider than your 50, that might be a better bet to get more shots in focus. Plus a wider lens is a bit more forgiving for minor subject movement than a longer one. Anyways, here's the set in the karaoke room.

Jo's sing a long

I've since bought a k5iis and it focuses waaaaay better in lower light - but I'm curious how it would do in a similar situation and whether I'd have to manually focus again...
02-10-2013, 05:04 AM   #13
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First of all, thanks to everyone for the useful answers.

All in all I think I need to practise, but I'm considering the option of buying a focusing screen as well (about that: is it easy to install?).

I wouldn't use the assist light or a torch, because they're not so discreet. Furthermore, this is the reason why I don't like using Flashes.

I don't shoot literally “in the dark”: there's often a dim light, but also people moving around which makes it difficult to be precise with the focusing at f1.4 or 2, therefore I get blurred pictures, “slightly out of focus” but not in Capa's cool way...

Emiliano
02-10-2013, 07:47 AM   #14
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I use the S type screen from Focusing Screen
02-11-2013, 06:00 AM   #15
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QuoteOriginally posted by emiliano Quote
I'm considering the option of buying a focusing screen as well (about that: is it easy to install?).
It's not difficult, but it is time-consuming, since you have to calibrate it to your camera with shims to achieve correct focus.
I couldn't find one that showed shim installation. If you don't have a good pair of focusing screen tweezers like the ones in the video, you can pop the latch with a dental pick and use the plastic-tipped tweezers that come with most focusing screens. Regular tweezers will scratch the screen, so make sure you use plastic ones.

I've done it many times & while it's relatively easy, you'll no doubt need to change the shims to get correct focusing. That involves installing the screen, taking a test shot with a fast lens wide open to check for back or front focusing, removing the screen, changing the shim, replacing the screen, taking another test shot, etc etc etc... until it's right.

Here's a thread you might find helpful.

Just be careful, work in a clean environment, and wear latex gloves while you're handling the screen & you should be ok.

Good luck,
Bob :-)
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