DOF question with longer focal lenght

I want to try some portraits with either a 55-200mm or 70-300mm lens. I normally used a normal lens, 50-85mm range for portraits. I want to experiment using the teles.

For those who have used teles for portraits, what are the optimum distance from subject and f stop for nice faded backgrounds? I plan on playing around with different distances just want a good starting point to play with.

I like to shoot as 130 - 200, F2.8 -3.2, background about 10 feet behind subject.

blackdiesel said:

I want to try some portraits with either a 55-200mm or 70-300mm lens. I normally used a normal lens, 50-85mm range for portraits. I want to experiment using the teles.

Click to expand...

50-85 is tele on a DX. The normal is 30-35mm.

blackdiesel said:

For those who have used teles for portraits, what are the optimum distance from subject and f stop for nice faded backgrounds? I plan on playing around with different distances just want a good starting point to play with.

Click to expand...

There is no optimal distance, it all depends on what you want to get. A full body portrait needs a longer distance than a half face portrait, depending on the aperture and the focal length and how much OOF background you wish for. I use the 50/1.4 or the 105/2.8VR macro lens. Both very nice in my opinion and I have no experience with neither the 55-200 nor the 70-300. The 70-300 VRII is on my list though...
--
http://www.olyflyer.blogspot.com/

blackdiesel said:

For those who have used teles for portraits, what are the optimum distance from subject and f stop for nice faded backgrounds? I plan on playing around with different distances just want a good starting point to play with.

Click to expand...

1. Get yourself a DoF calculator. I like to use this one:

http://www.tawbaware.com/maxlyons/calc.htm

I suggest using a CoC of 0.016 on Nikon DX cameras.

2. If your goal is to utilize DoF to achieve subject isolation, the critical factor is generally not the length of the lens, the aperture, or the subject distance! It's the distance between the subject and the background. You've got to position the subject well away from the background.

--
Randall Branham

I like to use my 300 VR F/2.8 at F/2.8 about 30 feet away , this gives a muted boka background I really like
Randall

This was shot at ISO 800, f5.6 and at 200mm. I personally think that some great portraits can be had with this lens. I could have gotten more blur in the background if I had backed up to 300mm and shot at the same f5.6, but my working distance was pretty far at that point since I wanted to get their whole bodies in the image. This is a good budget lens to do some portraits with. Most forget that at 200mm and f2.8 it can be hard to get enough depth of field to get from nose to ear, which most people want at a minimum. This lens doesn't have that of course, but it is something to keep in mind. Most professional portrait shooters that I know shoot at f4-5.6 for these types of shots just so they know they have the whole subject in focus.

Hope the example helps a little.



--
Wow...that's a pretty killer camera! Are you any good?

-Jake-

3.2 at 200mm you will be fine other then a maybe a tight head shot. The picture you shot below (two people full body) would have looked great at 3.2. No need to shoot that at 5.6.

Jake Loves Good Glass said:

This was shot at ISO 800, f5.6 and at 200mm. I personally think that some great portraits can be had with this lens. I could have gotten more blur in the background if I had backed up to 300mm and shot at the same f5.6, but my working distance was pretty far at that point since I wanted to get their whole bodies in the image. This is a good budget lens to do some portraits with. Most forget that at 200mm and f2.8 it can be hard to get enough depth of field to get from nose to ear, which most people want at a minimum. This lens doesn't have that of course, but it is something to keep in mind. Most professional portrait shooters that I know shoot at f4-5.6 for these types of shots just so they know they have the whole subject in focus.

Hope the example helps a little.



--
Wow...that's a pretty killer camera! Are you any good?

-Jake-

Click to expand...

Well, you DID look at what lens he used as an example, didn't you? (Hint, the 70-300 is f/4.5-5.6). I suspect that's why it was shot at f/5.6

Svein
--
Hi! I'm a .signature virus!
Copy me into your .signature to help me spread!

What Karl meant is, I think, the relevance of faster lenses. Faster compared to the 70-300. With F/3.2 you will get a better background blurr, still lifting out the subjects.

But the point Jake is making is relevant in many other fields. If it wasn't for the the need to have fast shutter speeds in indoor sports, I would certainly keep the aperture close to F/4. I've had numerous occasions where the 70-200 at F/2.8 got the gymnast sharp for only 2/3 of the body. If the iso/shutter speed permits and depending on my position, I prefer F/3.5 to F/4. I've had several well composed picture thrown away because stretched out feet and hands were totally out of the DOF range.

In fact, I seriously considered the sigma 100-300 F/4 HSM , but I think I need to wait for my next camera body to make that lens work for me. Maybe when the D400 achieves a serious high iso improvement ...

lock

Exactly. With the shot I provided, I would have preferred to shoot at 300mm. With compression I would have had a better background blur, but in the end I was happy with the result of this shot. My 35mmf1.8 also made a very good showing on this session and my 85mmf1.8, as always, was the king of bokeh. All around a great portrait lens on my D300. When shooting with full frame or film, I still absolutely adore my Sigma 105mmf2.8 for portraits.

--
Wow...that's a pretty killer camera! Are you any good?

-Jake-