So, everyone recommended the 50mm f/1.8 lens because they said this lens is “the best lens and it’s cheap!”. You got the lens and now you are wondering what they were thinking. “This lens in horrible. How is this supposed to be a ‘low light lens’ when all my photos are blurry?” you ask yourself.
Well, I hope to educate you on how best to use this lens and other lenses that have similar characteristics.
What is the 50mm f/1.8?
The 50mm f/1.8 (or its ‘faster‘ sibling, the f/1.4 ) are prime lenses that have been made for a standard in photography for many years and will probably be around for a long time. The term “prime” means it’s not a zoom lens. The lens’ focal length does not change. To “zoom” in and out with this lens, you must physically move forwards or backwards, otherwise known as “sneaker zoom”.
For many years, prime lenses have been of superior image quality (IQ) than their co-habitat zoom lens. This has been true until the last 5 or so years, when zoom IQ has greatly increased. These zoom lenses, such as the Nikon 24-70mm 2.8G, may have caught with the IQ of primes, but nothing can touch the small size and fast ‘speed’ of prime lenses.
Why use the 50mm f/1.8?
When a lens is referred to as a “fast” lens, they are talking about the large aperture of the lens. The large aperture allows more light to enter the front of the lens and then enter the viewfinder / sensor. Since there is more light, the shutter speed will be faster. Hence, a fast lens.
As a fast lens, the 50mm is great for low light. Your friends were right about that… but there is some compromising you need to do with a “low light lens”. This is where the problem lies.
Problem with using the 50 mm lens in low light.
When you understand the problem and know how to control it, this problem turns into a feature and this feature will help you enhance your photos.
So now you know that the large aperture of the 50mm f/1.8 (or f/1.4) lens is great for low light situations. Fantastic! But why are you still getting blurry photos when the shutter is faster? This is because the larger aperture of fast lenses keep less in focus when shooting at the larger aperture (i.e. f/1.8). You know those creative photos where the background (or foreground) is out of focus (OOF)? This is why… one of the few contributing factors that control what is called Depth of Field (DOF). We’ll keep the other factors for another post.
Solution
So now you’re indoors with your low light lens and taking photos of children running around at f/1.8 because, you know, that’s what the lens if for. So why are your photos blurry?
Wait, are they blurry or are they out of focus? Here is how to tell:
Blurry photos tend to have been taken with a slow shutter speed which causes blur. Either this blur is your subject moving or camera shake. (I’m assuming your caffeine fix wore off from the morning and this isn’t causing more camera shake.)
A shutter speed value that is too slow to hand hold successfully depends on the sensor size, focal length your lens is at, and how well you can hold the camera still. A standard guideline for a cropped sensor like the Nikon DX or Canon APS-C bodies is 1/(2 x Focal Length). For example, say this is a 50mm 1.8 you have. I would try to shoot 1/100th of a second or faster. Could you use a slower shutter like 1/60 sec? Sure, but it’s now your job to hold help eliminate the camera shake. Also with slower shutter speeds, if your subject is moving fast, they might appear as blurred.
Out of focus photos are those where the plane of focus has fallen outside where you intended. These photos usually have one or more of the following explanations for being out of focus.
- Miss focus – You or the camera didn’t focus on the right subject. Yes, sometimes you can’t blame the equipment. For example, when two people are standing next to each other, there is a space in between them, and your focus point is in the middle. Woops, you just focused on something behind them.
- VERY Shallow DOF – This is where the DOF of focus is so shallow that when you focus on the eyes, the nose, ears, and hair are out of focus. Some people like this sort of shot, but some people will complain the entire face isn’t in focus.
- Moved from Plane of Focus – This is the biggie. The#1 reason this lens, and others, are cursed out loud and sometimes in multiple languages. When focusing on a subject and using a large aperture (lets say f/1.8), the plane of focus is pretty shallow. If the subject moves out of that plane it will be come out of focus. Also, if you move the camera forward or backward, this plane moves with the camera so the subject could become out of focus due to you moving the plane. Example #1 below shows a center film canister that is in focus. You can see the small plane of focus by looking at the small area of carpet that is sharp. If this canister grew legs and moved towards (or away from) the camera, it would leave this plane of focus and become out of focus.
Example #1 – Film @ f/1.8
I hope this tutorial helped you understand fast lenses like the 50mm 1.8. If you have any questions or concerns please leave a comment below or email us at help@whatswrongphoto.com.
Tony
Hey, nice explaination, that was helpful. I think for me the trouble is with too shallow DOF and the last point about “moving out of the plane of focus” (especially when I use too shallow DOF and a focus recompose method)
Feb 07, 2010 @ 3:46 pm
Jolynn
Interesting, and very informative. I will definitely be checking back here regularly!!
Feb 08, 2010 @ 6:23 pm
Abdul
Great explanation. I have always been keen on getting this lense to go with D40. This has cleared up alot of unanswered questions I had. Thanks.
Feb 16, 2010 @ 8:20 pm
WhatsWrongPhoto
Abdul, Since you have the D40, you might want to look at the Nikon 50mm 1.4G AF-S as this lens will Auto Focus on your camera. The 1.8 models will not. Also, the 35mm 1.8G AF-S will Auto Focus on your camera too.
Feb 16, 2010 @ 8:49 pm
Abdul
Thanks for your reply. I am on the lookout for 35mm 1.8G AF-S since it will AF. But I might be getting a deal for the 50mm 1.8 for quite cheap. Will know tomorrow if the deal is on. Cant wait to DOF my kids
.
Feb 20, 2010 @ 8:33 pm
Barb
So then how do you determine what aperture will give you the depth of field you need? My old FD lenses have measurements marked on them so that I can tell that everything within a certain range will be in focus.
Mar 20, 2010 @ 10:42 pm
WhatsWrongPhoto
Barb,
Depends on the lens. The Nikon 50mm 1.8D lens has the DOF scale on the lens, but only displays starting from f/11, while the Canon FD lens you have which starts at f/4. Because the focus ring throw is so short on auto focus lenses, the DOF scale is very bunched up.
To calculate DOF, you’ll have to a DOF calculator: http://www.dofmaster.com/dofjs.html.
Mar 21, 2010 @ 3:12 pm
Steve
So then how do you determine what aperture will give you the depth of field you need? My old FD lenses have measurements marked on them so that I can tell that everything within a certain range will be in focus.
May 28, 2010 @ 7:23 pm
Emily
Thanks for your reply. I am on the lookout for 35mm 1.8G AF-S since it will AF. But I might be getting a deal for the 50mm 1.8 for quite cheap. Will know tomorrow if the deal is on. Cant wait to DOF my kids
.
Jun 02, 2010 @ 1:16 pm
WhatsWrongPhoto
The 35mm 1.8G AF-S lens is a great lens. Very much worth the purchase.
Jun 14, 2010 @ 1:45 pm
Jamie
Okay… my problem is that if I try to use this lens for more than 1 (or sometimes 2) people, most of the people are out of focus. How do I get it to focus on all my subjects (like a family), while making the background out of focus? Should I just not use this lens? It is my sharpest lens as of now. Do you have any suggestions for a lens that might work better for this?
Nov 05, 2010 @ 7:22 pm
WhatsWrongPhoto
Balancing DOF is almost an art in itself. The main thing you want to do is make sure that your subjects are in focus. Now this depends on the distance between the lens and the subject, and aperture. The online DOF calc is a good way to see the numbers involved in DOF.
Now, when you get your subjects in focus, one little trick you can do is move them far from the subject. The farther they are from the plane of focus, the more out of focus they will be.
Nov 11, 2010 @ 7:01 pm
Patricia
i know this is an old thread, but thought i would give it a try.
i just bought a nikkor 50mm f/1.8 AF for my Nikon D40x (i didn’t go with the f/1.4 because it was WAY too expensive). i don’t know all that much about cameras, but love the look of the sharp subject focus with the blurred background.
anyway, my question is how to use the different aperture settings? it has the range from 1.8 to 22, but seems to only work when set and locked at the 22. otherwise i get a message to set it to 22 and lock it.
also, in reading other responses you’ve given, how do you alter the shutter speed? if my ideal is 1/100th of a second, how do i adjust my shutter to that speed?
forgive me if these are silly questions, as i said, i don’t know much about camera jargon. thank you so much for your time!
Apr 14, 2011 @ 5:36 pm
admin
Yes, the 50mm 1.8D is a great lens.
Don’t think anything different when using this lens. You meter and change your settings the same way. Use the command dial to change the shutter speeds and aperture value.
The aperture ring is used on older bodies and newer bodies that allow for using the ring. The camera is right that you need to set it to the minimum aperture size.
Apr 14, 2011 @ 7:15 pm
Bret Baker
A lot of my pictures taken with the Canon 50mm f1.8 are not exactly blurry but they’re not as sharp as I’d like them to be.
Examples:
http://asktheduplex.blogspot.com/2011/04/winchester-mystery-belt.html
http://asktheduplex.blogspot.com/2011/03/itty-bitty.html
any idea what my problem could be?
Apr 18, 2011 @ 4:43 pm
WhatsWrongPhoto
I looked at your photos and I can see what you mean. Do you think you could email me (help@whatswrongphoto.com) the pre-blog uploaded JPGs with EXIF data and some of the post processing you did? There are a few factors that it could be here, but with that info I’m sure i could nail it down.
Apr 19, 2011 @ 2:27 pm
melissa
Hello! I too get similar results when using my canon 50mm 1.8 lens as the above post. Can you please help me out as well? I might add that when using this lens at a closer distance to my subject it is sharper!
Thanks so much!
Jun 15, 2011 @ 10:31 pm