Fred Frank Loc: Roanoke Alabama

I know focus is so very important. When I take a picture, ex wildlife, I’m disappointed when I zoom in on the photo afterwardsand it don’t seem to be as “in focus, as I first thought. Am I being to critical? How do professionals view this topic. How can I do a better focus job ?
I’m a novice using a D7100 and a 18-105 or a 70-200

rdrechsler Loc: Channel Islands Harbor, CA

Damn good question. I'm always surprised when something I thought was in perfect focus loses it when I zoom in. Seems to be that most of the time I'm causing it by ever-so-slight camera shake. I use the Nikon Vibration Reduction built into my lenses, but it doesn't seem as good as the shake reduction that my Canon bridge camera has. Thoughts, comments?

JPL

How about showing some samples? Then we can compare to our own experience and tell if you should be able to do better or not.

Until then I would say with a good lens and stable camera it should be possible to get sharp focus with most lenses at most apertures.

Key factors to sharp pics are:

Precise focusing.
Knowing the focus system in your camera and how to use it.
Fine tune lens against camera.
Keep the camera steady. Tripod f.x. Holding the camera correctly. Breath correctly.
Use lens stabilizing (no lens stabilizing will be as good as using a tripod for steady camera)
High shutter speed.
Using a camera without AA filter
Setting your lens at the sharpest f stop. Usually around f/8
Post processing.

CO

JPL listed all the things to look at. Also, how much are you zooming in on the photo? It will become more pixelated if you zoom a lot. You need to use lenses with a long enough focal length so you don't have to crop a lot. Can you post some photos? Post photos that have not been cropped.

brucewells Loc: Central Kentucky

The best way to ensure sharp photos is to mount the camera on a good tripod, regardless the camera/lens. Then, become intimate with the auto-focus system of the camera. Our minds tell us that since that shutter is so fast, we can just click away, getting sharp images as we do so. But, the camera/lens needs to be held firmly in place. This shouldn't be news to anyone and it is crucial to sharp images.

gvarner Loc: Central Oregon Coast

Here's my observations:
- Spot focusing is better than not.
- Focusing algorithms use the closest subject criterion.
- High contrast bright light scenes are easier to get a sharp focus.
- Low contrast scenes with an undefined subject can look soft on the monitor or in a print because your eye can't figure out where to land.
- Camera shake is more often the culprit than focus.
- Low light is tough to do with animals. Try to get a catch light in the eye.

bkyser Loc: Fly over country in Indiana

It really only matters that it looks good at the zoom/size you are printing. If you zoom anything in far enough, or crop it tight enough, it will look like crap.

Anything past zooming 100% is an exercise in futility. You really will only rarely be printing at 100%, so why pixel peep? You will only drive yourself nuts.

AzPicLady Loc: Behind the camera!

I never struggled with focus until lately. I don't know if it's my newer lens or the fact that I'm getting older. I do use a tripod, but sometimes even then things aren't perfect - or good enough to be acceptable. I've gone back to my older lens, and that does seem to help.

cdayton

One of my favorite shots is moonlight reflected through moored boats in Maine. It was shot with my D300 balanced on a dock rail and when anyone admires it hung on my walls, I reply, Yes, I used soft focus, and take credit for the artistic look.

jeep_daddy Loc: Prescott AZ

There are many things to consider when getting a subject in focus. First, if you use multiple focus points on your camera, the focus point that settles on the closest part of the subject will be the most in focus. In other words, if you point your camera at a tree when using 20 focus points, the leaves closest to you that one of the focus points settles on will be the most in focus and the leaves further back will not be as focused as will the background beyond the tree. So my number one suggestion is you change your camera settings to 1 focus point and learn it use only 1 but learn to lock focus so that you can recompose after locking focus and learn to move the focus point around in your viewfinder so that if the part of the subject is high, low, left, right, you don't have to recompose the subject after achieving focus.

Another thing to consider is that when composing your subject in your viewfinder, you need to make a decision on what f/stop you will be using. The smaller the number the more open the aperture is and the larger the number the more stopped down (smaller) the aperture is. The more stopped down your aperture is the more depth of field you will have. In other words, f/22 will give your image a broader range of focus verses f/2.8 where your depth of field will be very shallow and less of your image will be in focus. But the focus should always be sharp at the point you've chosen to put the single focal point.

Blur can also be caused by camera movement and subject movement. The faster your shutter, the less chance there is that some kind of movement from either camera or subject will blur your image. Beginners should consider using a tripod so that blur from camera movement can be eliminated entirely and you can focus on other things that might affect your picture.

amfoto1 Loc: San Jose, Calif. USA

I agree!

First thing.... are you being overly critical of your images? Are you looking at them too large on your computer monitor? For example, assuming your monitor is set to its native resolution, "100%" viewing of a 24MP image on it is like making a print that's approx. 4 feet by 6 feet... and then viewing it from 18 or 20" away! That's ridiculously large in most cases and way, way closer than a print that large would ever actually be viewed. How large will you actually be printing the image? It may be fine as a more reasonably sized 8x10, 11x14 or even 13x19 or 16x24" print! '

There's nothing wrong with zooming in at high magnification to retouch images and inspect details... but when judging focus, sharpness and even the appearance of noise in higher ISO images, it just doesn't make sense to look at it so large. It's bound to look like crap! Heck, even the Mona Lisa would just look like a bunch of brush strokes viewed up close "at 100%". Back off closer to the size you'll actually be using the image. Computer monitors also are usually not all that sharp. Frequently a print done with a photo-quality inkjet on smooth matte paper will look sharper.

Avoid heavy cropping for the same reasons. That's another way of magnifying issues, including focus accuracy. You mention using a 70-200mm and that would be a pretty short lens to use for a lot of wildlife photography, even on an APS-C (DX) like a D7100. I would bet you're doing some pretty significant cropping if that's your longest telephoto. When you crop an image heavily, you are amplifying any and all shortcomings, including focus accuracy. "Fill your viewfinder" with your subject by getting closer and/or using longer focal lengths. With wildlife I rarely use shorter than 300mm and often use 400, 500 or even 700mm or longer, even on APS-C cameras like yours.

The problem is, telephotos also are more susceptible to camera shake and make for shallower depth of field which is less tolerant of slight focus errors. It can help to stop down a bit, whenever possible and appropriate for a particular image. topping down increases depth of field and that in turn helps hide or minimize minor focus errors.

Also don't confuse camera shake blur or subject movement blur for focus issues. If an image appears blurred all over, near and far, that's usually camera shake blur. If only the subject or parts of the subject appear to be out of focus, but other things at the same distance are sharp, that's likely subject movement. In contrast, missed focus images will appear sharp in part, but the plane of focus will appear to be closer or farther from the subject.

Camera shake blur can be caused even by the internal vibrations of "mirror slap" in a DSLR. Longer focal lengths make matters worse. But image stabilization can help a lot... as can using a support such as a tripod or monopod... and as can a faster shutter speed.... or, ideally, all the above. It also may help to use Live View or "mirror lockup" feature that your camera might offer. When using really long lenses, I sometimes put a beanbag on top of the camera and lens, to help dampen vibrations. Plus, one reason I use carbon fiber tripods is because they do a better job absorbing fine vibrations than metal ones do.

Subject movement blur can only be counter-acted by using a faster shutter speed... IS and a rock steady support and precise focus can't help.

Also, do you have a "protection" filter on your lens? I've often seen image sharpness effected by filters, especially cheaper ones. Either the filter was blurring things overall... or were interfering with autofocus accuracy. A thin piece of glass really doesn't offer much protection (lens hoods and lens caps offer a lot more)... and UV filtration that was needed with film isn't necessary with digital... plus lenses are a lot tougher than most people think (watch Steve's video: https://www.youtube.com/watch?v=P0CLPTd6Bds). Try your lens without any filter, but with lens hood, and see if that makes a difference.

Okay, finally, let's talk about focusing!

There are three major components effecting autofocus performance and accuracy: the lens, the camera and the photographer themselves. Lenses use different types of focus drive... micro motor, stepper motor, ultrasonic. Micro motor tend to be used in cheaper lenses and to be the least consistent and reliable... while the other two are generally a lot better, as well as faster and quieter. Larger aperture lenses deliver more light into the camera for its AF system to work with... most cameras AF systems perform best with f/2.8 or larger aperture lenses (but larger apertures also make for shallower depth of field, so are less tolerant of error).

Camera AF systems also vary in capability, but most can work very well when the user sets them up properly for the particular situation being photographed. Many cameras today offer some form of focus fine tuning (pretty sure the D7100 does). A lens and a camera might both have their focus adjusted "within factory tolerances", but still not be very precise when used together if one is skewed a little one way and the other is off slightly the opposite. Used to be that you had to hand the camera over to a tech to be adjusted for focus accuracy... but today many cameras have built in means for the photographer to make their own adjustments. See you user manual for the procedure, but don't be too quick to make the adjustments until you understand it. Be ready to "undo" or "redo" it, too.... if you just make matters worse.

The biggest single mistake I see is people using the wrong focusing mode when photographing moving subjects. You MUST use a continuous form of focus with those (I think Nikon calls it AF-C... Canon calls it Ai Servo... not sure what Sony, Pentax, Oly etc. call it, but I bet they have it too).

The other focus mode is for stationary subjects. Nikon AF-S and Canon One Shot will achieve focus, then stop, lock and give you a "focus confirmation" (usually an LED flashes and/or a beep sounds). But if the subject is in motion or starts moving and distance between you and them changes, focus will be off. So this mode cannot be used with moving subjects. AF-C or AI Servo continues to focus and update as long as you maintain pressure on the button ("half press" on the shutter release or thumb pressure on a button on the rear of the camera). It never stops or locks, so is unable to give you "focus confirmation". I often hear peoples' cameras beeping at them while shooting at sporting events... and can pretty much assure you they'll miss focus on most of their images and not know why. They're using the wrong focus mode... user error! (But will probably blame the camera and lens! :sm16")

Another thing that optimizes your odds and makes possible to get a high percentage of your shots acceptably well focused is to use a single AF point, manually selected. This is more work for you because it takes some effort to keep that active AF point right on the subject, where you want the camera and lens to focus. That can be especially challenging with moving subjects. But it's the most accurate way and what I try to do most of the time.

When you use any form of multi-AF point focusing and rely on the camera to automatically choose among them, you give up some of the control. The camera can't "think" and doesn't know what's in front of it. Usually it will choose to focus on whatever is closest and covered by one of the active AF point. For example, a bird flying past in might focus on the closest wing tip, making the bird's head and body slightly out of focus and even more-so the farther wing tip. Multi-point AF also might be easily distracted by other object the subject is passing in front of or behind. These may seem minor errors, but when using a long focal length, especially at a larger aperture, depth of field can be pretty shallow... maybe only a few inches (it also depends upon distance... the closer you are, the shallower DoF will be... it DOES NOT directly matter what size sensor the camera uses, but that also has an indirect effect because you with larger sensors you necessarily use longer focal lengths and/or get closer to frame a subject the same way you would with a smaller sensor camera).

Cameras' focusing capabilities vary from model to model, too. For example, I use a pair of Canon 7D Mark II now and used a pair of the original 7D for about five years before that (all APS-C models). Those and Canon's 1D series models use a separate chip to drive their AF system, while the rest of Canon's models share the same processor to take images and operate the AF system. This makes the 7D-series and 1D-series camera's AF systems particularly fast to acquire focus and better at tracking movement. I also use a Canon 5D Mark II (full frame) that has a comparatively primitive AF system, which is nowhere near as good shooting moving subjects... I end up with a lot more missed-focus shots when I try to use it for anything that's not stationary. (Canon significantly upgraded the 5D-series AF system beginning with the 5D Mark III.)

Look up the specks for your camera's AF system. My 7DII have 65 points, all of which are higher performance "cross type". The center point (which is often the one I'm using), if further enhanced "diagonal cross type" when used with f/2.8 and faster lenses. In comparison, my 5DII has 9 AF point, only one of which at the center is "cross type". The rest are lower performance "single axis" (some horizontal, some vertical orientation).

I think your camera has similar... 51-point AF? 15 of which are cross type? You'll have to look it up to be sure and see which are which. Also check if there's a way to set it to only use the higher performance cross type. That might be something you'll want to do at times.

Cameras also often have other focusing tweaks that the user can use to fine tune AF for different circumstances. This varies a lot model to model and brand to brand, so look up what's available with your particular camera.

It also can help to simply take a lot of shots... use the cameras fastest rate of continuous shooting. This is to increase odds that you'll get at least one sharply focused shot. When I photograph something, I don't just set up and take a single shot. Depending upon what it is, I might take 5, 10, 100 or more! A stationary subject, I will usually at least take 2 or 3, re-focusing each. More often I take more, moving around the subject looking for different angles and taking extra shots, often re-focusing.

To facilitate this, I made sure all my autofocus lenses use ultrasonic drive both for its speed and because they're safe to override and "de-focus" to cause the camera and lens to re-focus. STM lenses can be used the same way. But micro motor generally cannot. With them it's necessary to turn off AF at the switch, before you manually focus the lens. Failing to do so and manually overriding the AF of a micro motor lens will damage the AF system in most cases.

Finally, something Nikon-specific... I have read and heard some far more experienced with them than me, that VR might slow AF slightly. I don't know why or if that's true, but there seems to be some supportive evidence. I also don't know if it applies to all types of AF that Nikon uses or is specific to certain ones. My own experience of using a variety of Canon IS lenses for over fifteen years is just the opposite... I feel that Canon's IS actually helps AF. I don't have any scientific evidence, though it just makes sense that a stabilized object would be easier to focus upon. Now, I'm sure the systems are different in some ways.... each manufacturer has their own patented design for in-lens stabilization. Besides Nikon and Canon, there are in-lens stabilization systems being used by Sony, Sigma, Tamron, and - at least experimentally with one lens I know of - Tokina. There may be others, but if you want to check into this beware of you'll have to look into this further yourself.

We all end up with some missed-focus shots.... we just don't share them!

But with good technique, good gear used correctly, some practice... and not being overly judgmental of our images... we can get a pretty high percentage of very adequately focused images. I shoot a lot of action sports and, when I'm in good practice and shooting familiar subjects, I average about 95% or better "in focus".

dar_clicks Loc: Utah

That’s a really good list of things to consider. The only thing I can think to add is that sometimes manually focusing can give best results.
- to the OP: No, you aren’t being too particular! It is best to have confidence to work with the equipment so results are what you want. (not always easy to figure out all the whys & where fors but a little study and experimenting usually helps)

Bunkershot Loc: Central Florida

Suggest you buy and download Steve Perry's e-book on mastering the Nikon Auto Focus system. I did and that ended my frustration with focus problems. Best $15 you'll ever spend.

aellman Loc: Boston MA

Use a faster shutter speed. Can be more effective than vibration reduction methods. >Alan

bkyser Loc: Fly over country in Indiana

I got the e-book as well. He also has a good youtube channel with lots of information on focus, and other things.

He's also a member of UHH.