Focusing with seemingly tiny viewfinders and screens?

[mara_ce]

This is an obviously newbie Q but I am having so much trouble knowing when I have "tack sharp" focus on my DSLR camera. I have a Nikon D3100 (probably not the best camera but the one I could afford right now - brought it used) and use mostly Nikon lenses with good ratings.

When I look through the viewfinder, it's relatively small (duh, right?) but things look okay. When I preview a pic on the camera's screen and zoom, sometimes I can get a better idea. Then, I get home and blow things up on my computer monitors and it's really rare that I get the tack sharp focus I'm after.

In terms of judging sharpness via the viewfinder or screen, are there some cameras that are better with this than others? Like, are there more expensive cameras with larger viewfinders and screens that make this easier to judge? Any tips regarding getting sharpness with my camera?

 

[Village Idiot]

This is an obviously newbie Q but I am having so much trouble knowing when I have "tack sharp" focus on my DSLR camera. I have a Nikon D3100 (probably not the best camera but the one I could afford right now - brought it used) and use mostly Nikon lenses with good ratings.

When I look through the viewfinder, it's relatively small (duh, right?) but things look okay. When I preview a pic on the camera's screen and zoom, sometimes I can get a better idea. Then, I get home and blow things up on my computer monitors and it's really rare that I get the tack sharp focus I'm after.

In terms of judging sharpness via the viewfinder or screen, are there some cameras that are better with this than others? Like, are there more expensive cameras with larger viewfinders and screens that make this easier to judge? Any tips regarding getting sharpness with my camera?

Yes, there are better cameras and probably better lenses, but technique also matters. Provide a photo and the EXIF. Shutter speed matters: slower shutter speed will allow camera shake to present itself giving you an unsharp image. The general rule is to keep your shutter speed about the same as your focal length, so 50mm focal length use 1/50 SS or faster. Aperture matters. Wide open will give you pretty bokeh, but often is not the sharpest. Going from f/2.8 to f/5.6 will not give you as shallow a DOF, but the image should be sharper because it’s using more of the center of the lens. Lenses with less elements will generally be sharper. Primes are generally considered sharper than zooms. A stepped down prime is even better. This is why professionals pay $1000+ for a lens compared to the sub $500 consumer versions.

 

[bratkinson]

Perhaps the 3 most perplexing problems to new photographers getting sharp pictures is:
1) understanding WHAT the camera will decide to focus on,
2) somewhat related, the out-of-focus areas that result from an unexpectedly thin depth-of-field (DOF, or plane of focus), and
3) the blurring, however slight, caused by camera or subject movement when photographing with a too slow shutter speed.

Cell phones differ greatly from DSLR cameras in that they have a somewhat 'wide angle' lens and a small sensor that puts almost everything in focus primarily to a large DOF, thus any Auto Focus point selected will put most everything in focus. They are truly the 'point and shoot' cameras of todays' world. Perhaps 90% of all photographs taken with a cell phone are quite acceptable and the other 10% still OK. Given the convenience of cellphone photography, most users would be 100% satisfied with their results.

DSLRs are on the other end of the spectrum. While the AUTO mode on most cameras does a very respectable job under a wider range of situations, in low light situations and/or with many auto focus points (AF) available, the results may not be a 'keeper'. In low light, AUTO may set the lens 'wide open' to get enough light (and thin DOF), it may also slow down the shutter speed causing blurring, or it may increase the ISO speed causing 'noise' (tiny multi-colored dots) in the dark areas of the photograph. The camera may do any two or even all three settings together to get a good exposure. And like many of us have discovered the 'hard way', when given a choice of multiple subjects to automatically focus on, the camera picks the 'near one' rather than the one we wanted to be in sharp focus.

Some new photographers try 'M' to put control into their own hands. Unfortunately, without a good understanding of the various compromises and tradeoffs of the exposure triangle as well as a limitations of the camera (mostly high ISO speed noise 'limits'), the results tend to be more 'hit and miss' than 'planned and expected'. Rather than 'jumping immediately into the 'M' mode, what worked for me in learning the ins-and-outs of digital photography (after 30 years with film cameras) was the 'P' mode and trying out various settings and let the camera decide the rest.

Perhaps the best place to start learning photography is to learn the exposure triangle first - Shutter speed, aperture, and ISO speed and how all three work together to produce a photograph. Maybe more than a year ago, someone on this forum referred to the exposure triangle as finding an 'acceptable compromise' of the various settings to get the picture in our mind. There's been times I've had to take pictures of a person at a podium in low light at 1/30th of a second, resulting in his hand being blurred, but fortunately the rest of him was still long enough not to cause other blurring. Other times, I've shot with such a thin depth of field as only the 'front man' in a group of singers was in focus, the rest were blurred slightly. It's trade a 'little of this' for a 'little better that'.

One of the free websites I like for learning photography is Cambridge in Colour - Photography Tutorials & Learning Community
Give it a look and see if explains things better than I have.

 

[MichaelHenson]

For me, I'm still a beginner (just a year into photography), the primary reasons for slight blurriness tend to come from camera shake. I don't think that simply switching to a camera with a better viewfinder will help. Before making that leap, giving up, or getting frustrated every time you take a blurry photo, I would focus on fundamentals.

• Ensure that your shutter speed is high enough to negate camera shake.
• Be sure your focus is actually on what you want in focus. (Can't tell you how many times I'll miss focus by millimeters in my viewfinder and find that the leaf just behind the subject's head is tack sharp but their face is unpleasantly blurry...)
• Learn better camera holding mechanics. For me, this was kind of unnatural and uncomfortable at first, but you have to learn to hold your arms, hands, body right if you want to be able to handhold your camera and shoot at semi-low shutter speeds.
• Use a tripod when you need to.
• Learn to use some flash. Whether it be bounced, diffused on camera, or off-camera. Better lighting helps freeze motion and gives your camera enough info that the photos can be much sharper most times.

Just some simple things to think about that I've had to learn over the past year. Don't give up! Keep shooting and just like everything else, you'll get better with practice!

 

[KmH]

Above, others have covered several things pretty good.

Your D3100 has a pentamirror type viewfinder. It only shows about 95 %, both vertical and horizontal, of the image the lens will actually project onto the image sensor.
Pentamirror type viewfinders cost less to make than the better pentaprism type viewfinder.

A further complication related to auto focus is that the main mirror in the camera that directs light from the lens up to the viewfinder is partially transparent so light from the lens can go through it to a small secondary mirror that redirects the light down to the auto focus module in the bottom of the camera.
In other words, since the addition of auto focus to DSLR and SLR cameras starting in the late 1980's, what we see in the viewfinder is not as bright now since some of the light goes to the AF module.

Next - AF is not a be all to end all.
There are situations when AF will not work well, if at all. So we need to be aware of those situations.
Study pages 55 - 63 in the D3100 Reference Manual. Page 56 of the D3100 manual show some of the situations when AF will have difficulty focusing.

As you study the Focus section of the manual note that you need to choose an AF mode, AND an AF area mode.

Another focus consideration is depth-of-field (DoF).
DoF determines how far from the camera acceptably sharp focus begins, and ends. DoF can be shallow or deep, and DoF results from several things:
• lens focal length
• image sensor size
• point of focus distance
• lens aperture

Here are some online tutorials that may help you better understand how to use your D3100 effectively:
Digital Photography Tutorials

 

[mara_ce]

Thank you so much, everyone!
What I am learning is that there isn't a quick way to learn exposure, which is actually good. The reason I started with DSLR photography is that I recently moved to a place with relatively less to do (NY to New England). I need a hobby that will engross my time.
I use autofocus occasionally but what I think is my best wide angle lens does not auto focus with my camera. Plus, I hear that serious photographers don't use autofocus. I generally shoot in ap priority mode and know a little about what aperture settings are best for certain types of pictures.
I previously watched some YouTube tutorials explaining the photographic triangle. I now also have Understanding Exposure by Brian Peterson on my Kindle and am reading through it. However, I just don't have the knowledge yet re: what settings to use when. E.g., I was standing on Fan Pier in South Boston the other night and was trying to figure out what settings to use in the dark to shoot Downtown Boston? Is there any way to take a tack sharp photo under those conditions (i.e., darkness but an illuminated city skyline)? It was 30 degrees and, when I got home, I was disappointed to find that I was nearly frostbitten for bad pics. Under the circumstances, I was wondering if there are any cameras that have better on-board equipment (larger viewfinder & screen) so that you can better determine at the time you shoot if you have a clear shot or not. Basically, I am understanding that if I know what I am doing, I won't need such things.
Hopefully with time. Thank you again!

 

[The_Traveler]

Plus, I hear that serious photographers don't use autofocus.

Also, very serious photographers stand on one foot while shooting.
Extraordinarily serious photographers don't even use a camera, but focus on a sheet of film using the bottom of a vintage Coke bottle for a lens.
The most serious photographers don't take advice that doesn't make sense.

 

[mara_ce]

Hey, there was a wink in there!

 

[Buckster]

While there are situations, or even lenses, that don't work well with AF, whenever possible, AF is the way to go. You just need to be careful that you're getting the focus lock indicator where you want the focus, and not on some other part of the scene. You will never be able to focus faster and more accurately than AF, aside from the few situations where AF doesn't work.

Speaking of lenses that won't use AF, just out of curiosity, what is that "best wide angle" you have that doesn't use AF?

If you really don't want to, or can't, use AF for some reason, you should consider getting and using a KatzEye focusing screen:

Nikon D3100 D3200 D5100 Focusing Screen - KatzEye Optics

 

[bratkinson]

One of the best tutorials I've found for nighttime photography was written by our own forum member Manaheim. It's well worth the read -
Manaheim's Ultimate Guide to Night Photography | Photography Forum

 

[mara_ce]

One of the best tutorials I've found for nighttime photography was written by our own forum member Manaheim. It's well worth the read -
Manaheim's Ultimate Guide to Night Photography | Photography Forum

Thank you for this!!! BTW - Manaheim got the shots of Boston from Fan Pier that I was going for!