Obtaining correct focus in low-light

mgilbuena

San Francisco Bay Area
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I recently purchased a completely manual and lightmeterless M4-P. Coupled with a Nokton 50mm F/1.1 lens, I shot a test roll of Kodak Gold 200 and got the results back last night.

In low light conditions, I have found it extremely difficult to obtain correct focus. What techniques do you employ? Do you focus on the catch lights in the eyes? The point of the ears (in cats?)

Here's a picture of my cat that the focus was completely missed upon. Indoors, afternoon, shot at f/1.1 at 1/30

With the light being so dim, I found it hard to make out whether or not the nose was correctly aligned in the focus patch. What things do you guys look for, and what would you have looked for in the cat if you were taking this picture?
 

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Focusing in low light is something you learn by practice. I first learned it with an SLR, learning to go too far and too little, choosing the middle where the best focus/contrast was. With RF the same applies except you aren't looking for contrast but coincidence.

You also have to learn to look for areas out of the plane of focus to focus on, then try to adjust to where the focus is needed. That is, a better lit area (or an area with more lines of contrast) just a little in front or behind the plane of focus, then adjust as best as possible. If you are acceptably close, you have the best you can expect. If right on, you can bragg how good you are. :p
 
You might have missed the shot because you moved.

Prefocus the camera, keep both eyes open, move your body to finalize focus (if the VF is clean and aligned, the patch "snaps" into focus), shoot. I get a much higher hit-rate like this.
 
What ferider said. It's easier to move you and the camera back or forward to maintain focus, assuming you have the subject in focus. Sometimes, it's easiest to attain focus using the edge of the rangefinder patch rather than the center. A 1.1 lens wide open at a close distance is also an issue.
 
I'm assuming you were probably 5 feet or so away from what you were focusing on? At 1.1 with a 50mm lens on a 35mm camera, you probably have about 2 inches of 'in focus' anyway. It wouldn't take much movement or rangefinder inaccuracy to throw off the focal plane.

My only experience focusing in low light has been with a Lynx 14 (with a patch that is difficult to see under good lighting conditions). If I don't have some sort of specular highlight to go off of, I'm at a loss as to how to focus in low light with it. I've ended up scale focusing at times when all else fails. Probably not helpful and I don't know if it matches your position - your camera is just a -bit- nicer ;).
 
Great responses and suggestions. I've never considered obtaining a focus and then physically moving back and forth for a final focus. It seems so obvious in hindsight.

The other suggestion to focus on a lit object and then making adjustments from there is also a nice idea. I'll try both of these with my next roll.
 
Oftentimes it is the shooter's eyes that have trouble in low light. A younger viewer might not have any problem at all in the same situation.

So the moral is: buy your Noctilux early when you still can see well.
 
"Don't shoot until you see the Whites of their eyes".

I tend to focus on the eyes, makes a good dark-against-light point, and you usually want the eyes in focus anyway.
 
My method: I stop down to f4 rather than shoot wide open, use a long exposure and push the film. Works for me.
 
When I shoot with my 75 Lux under low light I always use a Leica 1.40X magnifier. It really helps.

I also tend to look in the composition the areas of highest contrast, because this is where the viewers eyes will be drawn to. This area of high contrast is the easiest to focus. Dim lighting tends to make whites grey. Pre-visualize the contrast by squinting.

BTW squinting, even in bright light, will make the contrast more evident.

Generally I also limit the reach. Light fall off is inverse square law, where double the distance is quarter the light. Moving closer to the subject almost always increases the amount of light. I tend to shoot where my focus is limited to no more than 15 feet.

Practice focusing a lot. Some people say the focus throw of a Noctilux and 75 Lux is too big, but IMHO it is an asset. I always rack my focus from infinity and practice stopping without racking the focus back and fourth. I learned this from doing ENG (Electronic News Gathering) using video equipment.

I also practice a lot for street shooting where quick focusing is a valuable skill. Practice focusing fast all the time. I find that this helps a lot under hand held.

For me, under low light, using only one eye works the best. I figure my brain recieves a lot less information and is better to concentrate, accentuating what information I am processing. In otherwords: the info not in my viewfinder is to me like noise.

Good luck.

Cal
 
Cats are good for mastering precise focus, their always moving. In the meantime you can try static objects until you get a better feel of pinpoint focusing on a rangefinder. (some) People are pretty responsive to holding still for a picture.
 
Nikkor 8.5cm f2, wide-open, on the M8, used the 1.25x magnfier.

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Pre-focused and waited for the moving subject to coincide in the viewfinder. "Triggered" on the skate, the point of focus. The sock provided a brighter point, it was dark.
 
That is a good point; I was curious whether or not this lens may have been exhibiting focus shift. I was pretty certain I focused on the cat's nose, only to be surprised with the focus being on her back fur.

Since this is my first roll with both the M4-P body and the Nokton, I'll have to shoot more to familiarize myself more with the behavior of the lens and focusing quickly and accurately on a rangefinder.

I have 20/20 vision, but that still doesn't help in dim conditions :)

Presently, I am second-guessing whether or not something is in focus. "It looks to be in focus.. let me go a little past.. oh yeah now see? It's not in focus. Ok let's bring it back..." I've got to knock that off :).

Magnifier sounds interesting. Does this include all the framelines? Seems a bit pricey, though.
 
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I've found that focusing with the RFs are much easier than with the SLR in low light.

I can usually find something lit enough to focus on.
 
I always focus on the eyes, feline or human (Tri-X @f1.0)
 

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Magnifier sounds interesting. Does this include all the framelines? Seems a bit pricey, though.

On a M6 with 0.72 VF the Leica 1.40X magnifier works well with my 75 Lux, with a 50 I can still see the framelines, but I have to scan. I wear glasses BTW.

I bought the Leica 1.40X when it first came out. If I lost it I'd replace it right away because I own the 75 Lux. Using it with a fifty is a bonus. In other threads some Noctilux owners use the 1.25X which makes a 0.72 VF like a 0.9 VF. With my 1.4X my 0.72 VF becomes a 1.008 VF.

Another posibility is buy a M3. Buying a magnifier I believe is cheaper.

Cal
 
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