focus with 50 f/1.4

[lindy_c.]

I recently purchased a 50 mm 1.4 nikkor lens for portraits of children. I chose this lens for the beautiful bokeh it

produces when opened up to 1.4. However, When I shoot with the aperature that wide open, I am only getting a

small portion of the child's face in focus (ie; only the eyes or only the nose, etc.)

 

I understand the concept of DOF, however, what is the point of shooting a portrait at f/1.4 when it will not produce

everything (at least the whole face) in focus? I want to shoot that wide open in order to fully blur out the

background.

 

Does my problem have something to do with my camera to subject distance?

 

I will post a photo example.<div></div>

[nathan_stiles]

"Does my problem have something to do with my camera to subject distance?"

 

Yes. DOF is determined by focal length, aperture, and lens to subject distance. You should google for an online calculator for DOF-- there are several out there. I did read one article where someone claims that focal length isn't and actual factor, just a perception difference b/c of compression-- but I've never seen anything else to back that up.

 

"what is the point of shooting a portrait at f/1.4 when it will not produce everything"

 

Not a lot of commercial photos are shot that way. Though several "creatives" are.

 

The trick to blurring the background out, isn't as much about shooting in f1.4 (try f4.0 if you have the light), but having the background far behind the subject. Goes back to the DOF thing above.

[pamela_follett]

Ditto to Nathan. Another problem is the posing. When your DOF is so razor-thin, having the head tilted back at an angle away from the camera can cause serious problems. If he had been completely parallel to the camera, more of his face would have been in focus. To get a nice creamy bokeh AND sharp focus in relatively low light, you need to back up more, make sure your subject is further from the background, and try to ensure that his face is all in the same relative plane.

 

Also try really hard to ensure that the focus is on the eyes. If you misjudge the DOF, sharp eyes and soft ears can be a keeper, but sharp nose and soft eyes usually won't be.

 

I have the same lens, I love it, and I get great bokeh even at f5.

[Ed_Ingold]

There are two things you can do. The simplest is to shoot at f/2, f/2.8 or even smaller. The second is to get the eyes in a plane parallel to the camera. In either case, it is essential to focus on the eyes, not the nostrils as in your example.

[lindy_c.]

Thank you all so much! I will take the advice of having all of the face parallel to the camera. Can someone elaborate on this plane. I know that only a certain plane of info will be in focus, but is this a vertical plane, horizontal plane, how far does it typically extend? Also, in terms of backing up....

 

I would really like to have a tighter crop of the face (full frame). Do I need a longer lens to get that?

[matthew_newton]

It isn't really a 'plane' as such, it is really the surface of a sphere if you want to get right down to geometry. All points a certain distance away will be in focus, beyond or closer then a certain point and they won't be in focus. Just google 'depth of field calculator' and you can figure it out for all distances.

 

Rule of thumb, the closer you are to the subject the narrower your plane of focus. The smaller your f-stop the narrower the plane of focus.

 

You don't need a longer lens for a tighter crop of the face to get everything in focus, you need a wider lens or a smaller f-stop.

 

I can regularly get my son's (6 months) entire face in focus with my 28/1.8 wide open as close as I can focus with the lens (1ft, film body). The background is still pretty blurred. With my 50/1.4 wide open my plane of focus is narrow enough that if his head is turned I can't get his whole face in focus if I am focusing as close as I can.

 

You basically have a choice with your 50/1.4, either stop down slightly or get a wider lens. However a wider lens will begin to make the picture look distored with nearer features, such as the nose, look dispropotionatly larger then the rest of the face/body. That or you could backup and settle for not filling quite as much of the frame so you have a larger plane of focus.

 

If you look at most images, if the eyes are both in sharp focus it matters a lot less if the rest of the face/body are in focus. The eyes are what make the picture.

[charlesheckel]

To answer your specific question, the plane of sharp focus referred to above is parallel to the film plane, your sensor,

or the back of your camera--whatever you're most familiar with. You may wish to put your autofocus spot (brackets

in middle of viewfinder) on your subject's eyes, depress half way to lock focus, recompose, and shoot. You can also

move the autofocus spot to any of a number of positions in the viewfinder to make sure it's focusing on the

eyes.<p>Incidentally, when you're doing baby pictures, have Mommy lie on her back on the floor with her head

propped up on a pillow and baby on her tummy, back supported by Mommy's knees, or perhaps a small bolster.

Shoot past Mommy's head while she has animated and intellectual dialogue with her new zygote.

[charlesheckel]

Oh--in reference to your interest in a tighter crop, it depends. A short distance between camera and subject will produce foreshortening--nose like a lighthouse, tiny ears. A long distance will reduce foreshortening--"telephoto effect", face flat like a dishpan. The distance that gives a "normal perspective" for purposes of portraiture is five feet, at which distance a full frame of a baby face will be given by a focal length around 80 to 100mm.

[Ed_Ingold]

<i>It isn't really a 'plane' as such, it is really the surface of a sphere"</i>

<p>

Sorry to disagree, but practical lenses are designed so that the sharpest focus is in a plane parallel to the film/sensor with only small deviations. If you shoot a group, for example, you would arrange the group in straight line, not in a circle concentric with the camera, for best focus. The exception would be where the axis of the lens can be tilted. The focus is still a plane in that event but tilted according to the <i>Scheimflug</i> principle (q.v.).

[picturesque]

Research and read about DOF. Then go to dofmaster and download the program.

[jay_de_fehr]

Hi Laura,

 

I use a 58mm f1.2, both longer and faster than your lens, and for me, selective focus is an important compositional tool, and

I love the look. It takes practice, like anything worthwhile, but for me, the partially formed worlds of children cry out for this

treatment. Good luck!

[lindy_c.]

A couple of things in regards to your responses....

 

Pamela, if I back up any more I am moving further away from achieving a full frame of the face. Should I get have a longer lens so that I can back up but still have a close up shot.

 

Matthew, how will the wider lens give me a closer crop of the face? With the 28 mm are you able to move in a lot closer? I am just picturing more (unnecessary info) off to the sides with the wider lens. And yes, it is all about the eyes! When I took that picture above, I had thought that the whole face was in focus. This is what scares me! Sometimes I think I have gotten a bunch of great shots, just to find out later that many did not focus on the eyes! I have got to fix this problem!

[lindy_c.]

This weekend I am doing a photo shoot with a family (1 baby and mom and dad) Also their 2 dogs. I have to make sure that all of their faces are in focus! What if they are not all on the same plane? Would it just be best to sacrifice the great bokeh and use a small aperture to make sure of this?

[matthew_newton]

You will need to do this. If you can't get them all in focus at f/1.4, then try f/2 if that doesn't work f/2.8 and so on until you have all of their faces in focus. Most likely with the whole family in the frame with the 50mm lens you'll probably only need to stop down to maybe f/2.8 to get everyone in focus as you'll likely be standing a good distance back.

[User_502260]

I am not a big fan of overuse of selective focus in portraits. If you are going to use this effect then you want to make sure the eyes are as much in focus as possible. With many cameras this is difficult to do. Manual focus cameras typically have microprism, split image or combination focusing aids. These aids are in the center. Your point of focus might be away from the center. Manually focusing with AF cameras can also be difficult. I prefer to use a grid type screen with a manual focus camera so I can focus easily anywhere in the field of view. I mostly do this with Canon F-1 cameras with the LD screen. If the light is low I might use one of my Minolta X-700s with a grid screen instead. Other cameras that I use with interchangeable screens include two Nikon FEs, a Nikon N2020, a Mamiya NC1000S, two Konica bodies with permanently installed Nikon E screens and eight Bronicas.

[lindy_c.]

Thanks Jeff and Matthew! Your comments have been helpful. One more question if I may......

 

I will try to word this so that it is not too confusing.

 

If I have a group of kids, say three. And they are all at different distances (maybe one in foreground, one in middle ground, and one in background). If I want them all in focus I will obviously need a greater depth of field (smaller opening) but what if I am using autofocus and it focuses on the child closest to me; Will I still get them all in focus because they are within the DOF (field of view)????

 

Also, should I have my camera on the setting for dynamic area focus, closest subject or single area focus? I am using a Nikon D50. Thank you thank you!

[jan_m]

<p>Many photographers shoot a couple stops short of wide open as this is many times produce the best quality for that particular lens, so using a 1.4 lens does not mean you *have* to shoot with 1.4. <br />the 50/1.4 lens has been reviewed and compared to other lenses many many times (just do a search online) and you will find that the reason for owning it is not just for the ability to shoot with 1.4 setting. It can produce beautiful bokeh without shooting wide open that can be superior to other lenses with the same setting.<br>

Experiment with it to find which settings works for you and which styles you like. You can definitely use it to have the full face in focus and blur out the background.<br>

Selective focus can be an interesting creative tool and produce some dramatic shots, but usually the shots that clients want are ones with the full face in great focus. With this lens, you can have the range to do both.</p>

[lindy_c.]

<p>Back to my focusing issues.....<br>

Group of people with a blurred background. Not everyone on the same plane. Say I set my aperature to f/5.6 and I press the shutter halfway down to focus. Is it going to focus on just the face I am pointing at or will it focus on the f/5.6 depth and get the whole group in focus?</p>

[nathan_stiles]

<p>Holy dead thread, Batman! :-)</p>

<p>Well, f5.6 isn't a distance to focus on. It's a depth, not a distance. Your camera will focus on the object it thinks it should: which is dependent on how you have your AF set up. I set my to center, and put the AF center square on what I want to focus.</p>

<p>If the DOF for f5.6 is 5 feet at that distance, then when you focus on the person, you'll have roughly 2' of focus in front of them, and 3' behind them. There's online DOF calculators you can google for to get the actual numbers.</p>

<p>You have a TON of info in this thread now. And there is a lot of articles already on the web that are easy to find.</p>