prime lens

Mav · Jan 3, 2008

You're welcome.

Oh just to clarify, a lens doesn't focus closely because it's a prime. That has entirely to do with the optical formula in the lens. The Nikkor 35mm f/2 is particularly known for its close focusing abilities, but even 1:4.2 isn't all that close. But it's still a lot closer than 1:6.6 for the 50mm f/1.8, and 1:9.2 for the 85mm f/1.8. The little 18-55mm kit lens for Nikon (not sure which system you have) actually gets even closer at 1:3.2, but at f/5.6 it's too slow of an aperture and I would have needed iso4000 to get that same shot with all of our hands together which would have looked horrible. 1/15s was already too slow of a shutter speed and i wanted to stop down a bit to f/2.8 to get a little more depth of field, so I took a bunch of photos and picked the sharpest one. No other lens in Nikon's lineup would have gotten that shot.

NateS · Jan 3, 2008

Very true. That's the only thing about the 50mm f1.8 that I don't like is the lack of close focusing. I was very suprised the first time I tried to get a really close up picture of my son's face and it wouldn't focus close enough. Now that I've gotten use to it, it's not an issue, but don't plan on doing any type of macro work (IMO), without a reversing ring.

Edit: I know that you can't do "real" macro work with a kit lens either, but you can get close enough to make you feel like you're doing some type of macro work.

Mav · Jan 3, 2008

Oh @ julie.... I just saw your signature and website. Well whadayaknow! I love shooting children too! I'm my 9 month old's personal photographer, lol. :lol:

I've discovered that I really like using longer lenses for good head shots. I'm not sure what system you have, but I love the 105-135mm range of my 18-135 lens. This is at 135mm, wide-open at f/5.6 bouncing my SB-600. This lens is so-so in the mid-range but is amazingly sharp at the long end wide open.

I also posted some completely unprocessed straight off the camera samples of my 70-300VR (IS) over here.

I don't use that focal length enough to warrant buying something like the Nikkor 135mm f/2DC which is a pretty pricey lens, but if you do it all the time then something like that might be useful. The depth of field is already tight enough from the longer focal length that you get some nice background blur and decent subject isolation. You can just barely make out a "taggie ball" in the back right. Anyways, I blew that one up to 20x30" and it looked great. Not bad for cheap amateur glass. I love it when I find stuff that gives great results that you don't have to pay an arm and a leg for. :mrgreen:

julie32 · Jan 3, 2008

Hi Mav,

Your daughter is beautiful! I love the catchlight in her eyes. Are you on a tripod for this shot? I understand the definition of Depth of Field, but the terms that people are using before DOF, like tight, or short or long confuse me. Can you please explain that better for me?

Thank you!

Mav · Jan 3, 2008

Thanks! No, no tripod. This was laying on the floor down at "baby level", Auto ISO set at 400 but bumped it up to 500 (flash went to full power but it couldn't make it all the way so the camera bumped up the ISO slightly), 1/125s, f/5.6 (lens wide-open), and I think I actually had my SB-600 flashed rotated completely around and pointed behind me and up about 45-degrees so that it would just add to the light coming in from the window. And this was all with my cheap little D40 no less. Viewing the full-sized image at 100% you can see the front window that she's looking out at in her eyes.

Short just means a smaller focal length lens with a wider view, and vice versa for long. Tight just means you have a very narrow depth of field. Where something becomes short or long is a little bit subjective and depends on what you're shooting. For baby portraits indoor, 200mm is very long and 300mm is overkill. For birds in flight, 300mm is "short", heh heh.