How to manually focus Nikon d5100 at very low light conditions?

Question

Suppose I have to short in very low light so I have to set up shoter speed to 10-20 sec. Live view and autofocus doesn't work in this case and view finder give you a little help since it is to dark. The only thing I know for sure is distance to object, but I'm not sure how to rotate focus ring to focus on specific distance.

So there are actually two questions: 1. How to accurately focus in low light? I.e. you can't see sharpness in View finder. 2. How to accurately focus in almost zero light?

Asked by yura

Answer

Your best option is to light the subject temporarily somehow, than use auto-focus and focus lock (or better, switch to manual focus), remove the light and take the picture.

If you can't get enough light for auto focus to work but you still get get some light on the subject than use manual focus with live view (zoom in your live view to the maximum zoom to help with focusing).

Next best option is to use the lens distance scale if it has it - just stop down a bit to increase depth of field because those scales can be a bit inaccurate (also your subject distance is probably also inaccurate because if you can just walk up to the subject with a tape measure you can also walk to the subject with a flashlight and use auto-focus)

If you can't get any light on the subject and don't have a lens with a distance scale than your next option is to focus on something else that is approximately the same distance - this tends to be very inaccurate - so stop down to increase depth of field and use a depth of field calculator to make sure you have a wide margin of error (there are DOF calculator apps for all smartphones, or you can print a DOF table from an on-line calculator if you don't have a smartphone).

And finally, if everything else fail you can use the hyperfocal distance - when you focus to the hyperfocal distance (or behind it) everything from half the focus distance all the way to infinity is in focus, any DOF calculator will tell you the distance for a given focal length and aperture

If you use the hyperfocal distance, apart from giving up on blurring the background, you will also probably have to stop down because the smaller your aperture the closer the hyperfocal distance - and if your hyperfocal distance is smaller than your subject distance you have enough margin of error to get this right in the dark using approximate distances.

Also, you want to focus a bit farther than the hyperfocal distance because if you accidentally focus even a bit nearer not everything to infinity will be in focus and you can get an out of focus subject.

Answered by Nir

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How can a teleconverter allow manual focus lenses to autofocus?

Question

I've found that some discontinued teleconverters, such as the Pentax F 1.7x AF Adapter and Nikon TC16A, enable autofocus with manual focus lenses. How is this possible? Does this system have any significant limitations?

Asked by DragonLord

Answer

With the Pentax option, you're basically getting "close" with the manual lens using manual focus and then using the AF of the camera to move the lens elements in the teleconverter itself to adjust for more precise focus. Bear in mind that the TC is a lens itself...

At any rate, it's not perfect answer for making a manual lens do AF, but for the right sort of shooting, it's a very useful feature. I can't say for the Nikon option, but I would imagine that it's similar.

Answered by John Cavan

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How can I find infinity focus on a kit lens with no markers?

Question

I have a kit lens which has no markers. What would be a recommended way to find infinity focus on this lens?

I plan to shoot objects at night -- not necessarily stars or the moon. So, adjusting the focus using the viewfinder may not be an option.

Asked by publicRavi

Answer

I'd go to the aperture you want, go to live view, zoom in, and manually focus on the moon. For all practical purposes, it should be infinite. Mark it on the lens.

Answered by rfusca

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Are there DSLR lenses that don't allow for manual focus?

Question

I am looking into getting a Nikon soon (either a D3100 or a D5100). One of the reasons that I am upgrading from a point and shoot is because I want to have more control over the camera's functions. In particular, I want to be able to manually focus. As I shop for lenses, are there any lenses that don't allow for manual focus? Is there anything else I should look out for on this front?

Asked by Treebranch

Answer

If there are, I've never seen one.

They do not offer the same comfort for focusing. On cheap lenses, I noticed you have to turn the front element to focus which does not give much grip and also rotated the front element which is not good if you have a polarize filter.

Better lenses have a nice texture focus ring to let you easily change focus. There is also something called the throw distance which is how much you have to turn to focus. If it takes more distance to change focus than you can focus more precisely. This is often how macro lenses work.

The other nice thing is to have quick-shift focus (maybe called something not the same for different brands). This allows you to focus manually without switching to manual focus mode! You just turn the ring and it works. I find we can search for lenses with that feature for Nikon for example.

Answered by Zak

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Why doesn't pixel peeping with magnified Live View give the sharpest possible image?

Question

I've seen this comment (most recently in this question), or similar, in several answers here on photo.SE: "Pixel peeped images aren't likely to look sharp".

Why is that? It would seem to me that if you go into Live View, full magnification, and then manually focus on the area of interest, then that is as sharp as it is going to get. Of course, one must assume a stationary subject here, and you have to choose you area of interest carefully, but I keep seeing comments like that one which really imply that I'm missing something here.

So why doesn't pixel peeping with magnified Live View give the sharpest possible image?

Answer

You're misunderstanding the statement. "Pixel-peeping" during focusing is indeed a good way to get a sharp image. The statement "Pixel peeped images aren't likely to look sharp" means that the image won't look that sharp while you're doing the "peeping" because the viewing magnification is so high.

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How can I accurately focus manually on an APS-C DSLR?

Question

My favorite portrait lens is the Nikon 50mm 1.4G. I love the light and what it is capable of. My problem with it is that on my D90 the AF is sometimes horribly slow, and in many cases (mainly low light) I can't auto focus at all. I use AF lock as much as possible, but for many shots I really wish I could just use manual focus. The problem is that I'm usually wrong about whether my subject is in focus or at least completely in focus. So my question is...

Are there any recommendations you can make for training my eye to be sure my manual focus is accurate? Any diopter adjustments or calibrating tools? Any eye exercises to train myself to recognize a true focus?

I know that I would probably have better AF performance on a more expensive body, but for now I think it's good practice to train myself in manual focus anyway. Thanks for any assistance.

Answer

One of your problems is that the matte screen in your camera (this is what you are actually looking at through the viewfinder, it's a semi-transparent plastic screen that sits at the top of the mirror-house, below the prism housing) is designed to give a nice bright useable image through a slow autofocus lens such as your average f/3.5-5.6 consumer zoom. This is good if you are using a consumer zoom, but very bad if you are trying to focus a fast prime lens. The reason is that the extra screen brightness is bought at the expense of focus accuracy - is unable to show you the small depth of field at larger apertures than about f/2.8-ish. In other words, if you look at the image from an f/1.4 lens through this matte screen, the depth of field you see will be that of f/2.8 and not f/1.4. Again, for a consumer zoom this is entirely irrelevant but for a fast prime it is highly misleading. You physically cannot focus a fast prime accurately through such a matte screen; you are just not getting the information needed.

A solution for manual focusing is to replace the default "fast" matte screen with an old-school, coarse-grained one which will show you accurate depth of field for a faster lens, and more "pop" when things come into focus. You may also get a screen with a split-prism center, or one with a prism-ring round the center.

I'm not sure if Nikon offers such alternative mattes for the D90 but third parties might although installation is likey to be a bit more fiddly in that case. The downsides to a coarse-grained matte screen is that it affects light-metering, and that the view from lenses slower than about f/2.8 will be darker (much darker, in the case of an f/5.6 lens) in the viewfinder. The matte does not affect autofocus performance in any way though.

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What might cause stuck focus on a manual lens?

Question

So, today I dropped my ME Super. When I picked it up I realized that the focus ring of the 50mm f2 lens attached didnt turn. My question is, what could cause this? Could it be that the threads inside the lens which move the glass about are binding?

Answer

My problem was that the threads that move the elements were jammed. I was lucky as in this lens, a Pentax SMC-M 50mm f2, all of the glass was contained in a unit and a thread moved it back and forth or obtain focus. These threads had slipped and basically they were cross threaded. I would never try this on an autofocus lens or a zoom lens. That would be WAY to complicated. Even with a prime lens it took a lot of adjustment to get the distance scale correct and I couldn't even begin to imagine what a nightmare it would be on a zoom lens. Sorry jrista, a step by step would look like this: Disassemble Repair Reassemble Check focus Disassemble Adjust Reassemble And repeat......

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How can I find which lenses have “Continuous manual focus”?

Question

Canon lenses with USM auto focus can be called "continuous manual focus" (at least some). By this I mean that you can override the AF without switching it off. I've found this very handy, and I often miss this option when it's not there.

I know Sigma have HSM AF on several lenses, but I've encountered at least one of these which still requires me to "turn off" AF with a switch before I can manually focus. Does anyone know where I can find a comprehensive list over lenses from Sigma (and others) which have "continuous manual focus"?

Answer

This is known as full-time manual focus override (FTM).

If you look at the Sigma product catalogue (PDF) it mentions within each lens description if it has that feature.

Tokina AT-X PRO series lenses have what they call a Focus Clutch mechanism that allows you to override the AF. The only lens I'm familiar with is the 11-16mm f/2.8 which has this feature.

The only Tamron lens I know of is the 70-300mm Di VC. The 17-50mm VC unfortunately doesn't have it.

Canon USM lenses have the feature as pointed out in the original post.

Nikon AF-s lenses have the feature. Set a switch on the lens to M/A and you can manuall override focus.

You may need to have your camera's autofocus setting to single AF rather than continuous servo (or whatever your brand may call it) otherwise it will not let you adjust, or will override your manual adjustment.

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Why does Zeiss manufacture only manual focus lenses?

Question

I've heard that Zeiss's quality is very good/great but I'm also curious if it has anything to do with the "manual focus only".

I have read this question but it only partly addresses my question. Is it a company policy or what?

Answer

It is one of the lens design compromises they have chosen to make. While I don't think anyone can know for sure the reasons behind that decision, I can think of several likely ones:

• Zeiss's own most successful cameras are rangefinders, which do not auto focus. These are the only cameras they still make today.
• MF lenses avoid any complication from integration with an AF system, keeping the lenses smaller.
• Major SLR companies do not license their lens mounts. Companies like Sigma and Tamron reverse engineer the electronic communication protocols. Making an all-manual lens avoids this need — although recent Zeiss lenses do feature electronic coupling for aperture.
• It makes a niche, since lenses designed for MF are usually better for that purpose than those designed for AF. Good MF lenses have a long "focus throw" — you turn the focus ring a large amount to make a difference, allowing fine adjustments. AF lenses, on the other hand, are designed for smaller movements to optimize AF speed.

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How do I use manual focus on my Canon PowerShot SX210 IS?

Question

When I turn to manual focus setting in the camera, a bar appears on the right side of the screen which has measurements like 1 2 5 m. Increasing on decreasing that bar doesn't show any effects on the screen.

I haphazardly maximized the focus to infinite symbol for a macro shot. This resulted in a NOT so sharp image.

What is the way to use that?

Answer

According to the user manual, you first focus approximately using the screen and distance bar, then press the shutter button halfway to enable you to fine tune the focus. You need to be in M, Av, Tv or P mode.

If you are trying to focus on something close, the last thing you want to do is focus to infinity!

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Which is better - autofocus and recompose vs. manual focus?

Question

In some occasions autofocus doesn't focus what I intend it to. What is the better option - to use autofocus, focus what I want and recompose, or use manual focus in that situation?

Answer

In general, modern AF cameras have focusing screens optimized for bright viewing rather than accurate focusing. This means that the AF system is potentially more accurate than your eyes using the focusing screen, if the AF system is calibrated correctly.

I've found that the wider the lens is, the harder it is to achieve critical focus while focusing manually.

For critical manual focusing, either use Live view, if you have it, or install a custom focusing screen for your camera.

If you are using AF and recompose, I've found it useful to decouple the focusing action from the shutter release. Most cameras will let you assign focusing to a separate button, instead of having to maintain a half-press of the shutter while recomposing-

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Is it possible to get a larger screen for live view, for precise manual focus?

Question

I've been doing some test macro shots lately and it's been a pain to focus sharp. The macro lens already minimizes DoF and makes things hard but I've been thinking of an external screen that I can pan/zoom to check focus quality.

I haven't been able to find much, probably because I don't know the keywords to search for. I hope there is something on the market.

Is it?

At the moment I'm using the live view and the +/- keys to magnify the live view in order to check the focus quality.

What would be better alternatives considering I will use a tripod?

Answer

You are looking for an HDMI monitor.

Here you go, BHPHoto has 116 results for that.

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Live view on larger screen for precise manual focus

Question

I've been doing some test macro shots lately and it's been a pain to focus sharp. The macro lens already minimizes DoF and makes things hard but I've been thinking of an external screen that I can pan/zoom to check focus quality.

I haven't been able to find much, probably because I don't know the keywords to search for. I hope there is something on the market.

Is it?

At the moment I'm using the live view and the +/- keys to magnify the live view in order to check the focus quality.

What would be better alternatives considering I will use a tripod?

Answer

You are looking for an HDMI monitor.

Here you go, BHPHoto has 116 results for that.

Check more discussion of this question.

Do still photographers use follow focus, as filmmakers do?

Question

Is a follow focus system beneficial to photographers in low light or other situations? Almost all professional filmmakers use a similar system to manually focus lenses, but I am not aware of professional photographers that use it.

I find manual focus to be beneficial in many situations, such as low light, or even in instances where I am anticipating action very near to the lens against a distant background.

Overall I am looking for reasoning for and against this for photography.

Answer

"Real" follow-focus (he said, using the "no true Scotsman" fallacy) involves a separate focus puller in addition to the camera operator (whose job is primarily framing/composition). With a single operator (photographer), it's hard to manageboth the framing/composition and keeping an eye on the lens's focus scale. That, in itself, poses a bit of a practicality issue, since the working space is kind of cramped with a typical stills camera.

Yes, we did do something of the sort in the manual-focus days (with the photographer trying to maintain focus and framing at the same time, which required a bit of practice to develop the muscle memory required for each lens), but continuous autofocus has largely made this a solved problem in most instances. You can still do it, but it petty much requires either a replacement focusing screen or a small enough aperture to let DoF take care of minor discrepancies. A more standard approach with stills (especially in areas like runway fashion) is to prefocus the camera and wait for the model to hit the mark, so to speak.

What you will often see, though, is heavy use of focus memory in lenses that provide it (especially among sports photographers). Higher-end long lenses often provide a memory function that will allow you to preset focus points for quick recall when needed (so if you are shooting, say, a baseball game, you can have first base in memory and catch the play at first without having to wait for autofocus to home in on something). There are outboard systems available (usually at horrendous prices) that can add similar functionality to just about any lens -- they're designed for use in the SLR cine world, and while they're cheaper than high-end cine/video equipment, "cheaper" is definitely a relative term.

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In which situation should you NOT use the manual focus?

Question

Couple of weeks back I discovered the power of manual focus and now for EACH and EVERY shot I use manual focus!

Are there some situations where manual focus doesn't make much sense and we should allow the camera to do the job? Any examples would be helpful.

Answer

I sports/action photography, especially in good light conditions, the autofocus will (probably) manage to focus on the action mucht faster then you could. Thus manual focus would then make you miss shots.

Bassicly any type of photography that requires you to be very fast.

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How can I get sharp manual focus despite poor eyesight?

Question

I suffer from astigmatism. It's only mild, though I feel it's affecting what I'm seeing when looking through the viewfinder. Frequently, after shooting a photo with my Canon EOS 7D, I'll load it into Lightroom and discover that what looked sharp as an LCD preview is actually not at all in focus when you get down to the 1:1 level.

Normally I let auto-focus do all the work, so I attribute this to back-focusing effects that I'm not picking up on when looking through the viewfinder.

Today, I switched to manual focus while using my tripod to see if I could do a better job than the AF. Rocking the focus ring back and forth, I found it hard to distinguish the point where my subject is in focus (blurry -> slightly blurry -> blurry); indeed, when I got back to Lightroom I still found about a third of my shots came out slightly off-focus.

Is there anything that I can try that could improve my shots, particularly anything that would reduce/nullify the effect of my eyesight while using the camera? The obvious answer to this could be "wear glasses" -- which I do, but not while using the camera, as I feel like they're in my way every time I peer through viewfinder!

Update: I've marked the Katz Eye answer as accepted, as I've used one previously on a Minolta film camera; it really helped when focusing. However, all the answers here are great and have been very helpful.

Answer

Pixel peeped images aren't likely to look sharp unless you're viewing from a distance... Something to bear in mind.

However, for manual focus improvement, you may want to consider a custom focussing screen such as the Katz Eye split prism screen. The basic idea here is much like a rangefinder camera, the prism splits the image when it is out of focus and when it is brought into focus, the image lines up. This can assist quite a bit, especially with poorer eyesight.

On the plus side, it will help confirm if your camera autofocus is iffy.

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How to use manual focus in Canon PowerShot SX210 IS

Question

When I turn to manual focus setting in the camera, a bar appears on the right side of the screen which has measurements like 1 2 5 m. Increasing on decreasing that bar doesn't show any effects on the screen.

I haphazardly maximized the focus to infinite symbol for a macro shot. This resulted in a NOT so sharp image.

What is the way to use that?

Answer

According to the user manual, you first focus approximately using the screen and distance bar, then press the shutter button halfway to enable you to fine tune the focus. You need to be in M, Av, Tv or P mode.

If you are trying to focus on something close, the last thing you want to do is focus to infinity!

Check more discussion of this question.

How should I chose a manual focusing screen for my Pentax K10D?

Question

I am considering buying a split focusing screen, replacing the original one. I would like to use some split/microprism screen to ease the focusing of the manual lenses. I own both kit lenses (18-55, 50-200) and two primes (50/1.7, 28/2.8).

I found three solutions for the problem:

1. Katzeye — this is the best one, although its quite expensive
2. focusingscreen.com — acceptable price, looks good
3. some cheap screen from Ebay — no quality info

My main problem is that I would like to use it with both kit and manual lenses and I read that some of the screens have problems with autofocusing lenses.

Katzeye works fine although it's quite expensive.

Focunsignscreen.com screens also looks fine, but I could find any info about it.

So in general I would like to get some basic opinions, experiences about focusing screens on K10d, mainly about the focusingscreen.com type.

Answer

On the installation instructions at: http://www.focusingscreen.com/work/k7en.htm there is the statement:

Penatx [sic] ISTD/K7/K10D/K20D change focusingscreen will not influence AF-Focus and focus point operate.

So it seems to be working with autofocus.

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In film cameras with film advance levers, what happens if I don't crank the lever all the way?

Question

In film cameras with film advance levers, what happens if I don't crank the lever all the way? Will the lever 'remember' the last position it was at and keep the shutter button locked until I crank it the rest of the way, or will the film only advance half a frame and I'll double expose half of the previous frame?

Answer

It depends on the camera. Most 35mm film cameras (especially more "modern" ones :) do two things when you wind on - they advance the film roll by a frame and they reset the shutter curtains to the start position. My last 35mm film camera (a Praktica SLR) wouldn't allow the shutter button to be pressed unless I'd fully wound on. However, there was a button I could press while winding on to disengage the film-winding mechanism: this would result in the shutter being reset but the film left in place and could be used for double exposures.

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