Looking for lens with very low f-stop number

[bkond08]

Hello. I love the look of photos with very low DOF's where the background is blurred. The smallest f-stop number my current lenses go to is f/4. I have been looking online at lenses but am not sure if I am totally off base as to what to get (I am relatively new to DSLR photography). I also was looking for something that might be better in low light situations. This was the one I was considering. Am I looking at the right lens? I don't have a ton of money to spend. Thanks in advance.

It's the Nikon 50mm f/1.8D lens...

http://www.bhphotovideo.com/c/produc...kkor_50mm.html

[bkond08]

Sorry, I forgot to add that I just have the Nikon D40x.

[JimC]

That lens isn't going to Autofocus on a D40x.

The Nikon D40, D40x and D60 models require lenses that have focus motors built in if you want Autofocus. For example, Nikon's AF-S (Silent Wave Motor) lenses or Sigma's HSM (Hypersonic Motor) lenses. For other brands, you need to take them on a case by case basis (some have built in motors, some require that you use a camera body that has a focus motor built in). The Nikkor 50mm f/1.8 AF lens would work using manual focus on a D40x. But, it's not AF-S, so it wouldn't Autofocus on your camera.

Nikon has a new 50mm f/1.4 AF-S lens now. Sigma also has a newer 50mm f/1.4 HSM lens. These would both Autofocus on a D40x, but they would cost you a lot more. Nikon also recently announced a 35mm f/1.8 AF-S (Silent Wave Motor Focusing) DX lens that would Autofocus on a D40x. But, you may prefer a bit longer focal length, depending on what you're trying to shoot. You can read more about that one here:

http://www.steves-digicams.com/digin...l#nikon_dx35mm

For a shallower DOF with your existing lenses, you can zoom in more and/or move closer, so the subject fills a greater percentage of the frame (go for a tighter head and shoulders shot versus a full length shot).

[bkond08]

Thank you for your response. I was aware that it wouldn't autofocus, but I plan on upgrading my camera body hopefully soon. I am also going to check out the other lens you mentioned.

[bkond08]

Another question....so if I upgrade my camera to a D200 or D300, will AF-S lenses autofocus on thaose camera bodies?

[JimC]

Yes. The D200 or D300 will Autofocus with AF-S lenses. They'll also Autofocus with Nikon's AF lenses that do not have a focus motor built in (like the 50mm f/1.8 AF lens you posted a link to).

Currently, the only Nikon dSLR bodies that do not have focus motors built in are the D40, D40x and D60. So, these require lenses with focus motors built in if you want Autofocus. Other Nikon dSLR models (D50, D80, D90, D100, D200, D300, etc.) can focus with either Autofocus lens type (with or without a built in focus motor), since they have a focus motor in the camera body, too.

[JimC]

If you plan on going to a model with a larger sensor later (for example, the D700 or D3), you may want to consider sticking with lenses designed for 35mm film or sensor size.

Nikon's DX series lenses are designed for models with an APS-C size sensor. Although you can use them on Nikon's dSLR models with larger sensors, the camera would crop the image (ending up with a lower resolution image, just as if you'd cropped it later with an editor). So, you'd end up with the same angle of view you'd have using a lens on a camera with an APS-C size sensor.

[JohnG]

One other thing to add - once you get into prime lenses you really want to match the lens with the type of photography and specifics of your shooting style. Or another way of stating this - how do you know 50mm is the right focal length for what you want to photograph? To get shallow DOF photos with a 50mm lens you really need to be within several feet of the subject. Sometimes that's easy to do and some times it's not. And, of course, the opposite is true - on a 1.5 crop camera, 50mm can be tight for some types of shots and a wider prime is necessary. So what types of subjects do you plan on photographing?

[dumathecheetah]

Hi JohnG,

Thank you and the other posters in this thread--very useful information.

I too am looking for a cheap low f-stop lens to get for my D40x to better achieve the blurred background effect (and to use in low lighting conditions). With respect to your post, I have a few questions: What is a "1.5 crop" camera? Is the D40x a 1.5 crop camera? If so, and if I'll be limited in my ability to take a close-up shot of something (within a few feet of it) with a Nikon 50mm f/1.8D lens, given everything else the same about the camera shot conditions, will having a lens with a lower f-stop limit (e.g., 50mm f/1.4 AF-S lens) be able to compensate for the cropped picture and give me a wider left-right field of view?

I'm sorry if it's unclear what I'm asking. Please let me know if so.

Thank you in advance.

[TCav]

The list of inexpensive, large aperture lenses for Nikon is short, and the list of ones that will AF on your D40X is even shorter:

• Nikon 50mm f/1.8D
• Nikon 35mm f/1.8G AF-S
• Pro-Optic 85mm f/1.4
• Nikon 50mm f/1.4D
• Nikon 35mm f/2D
• Voigtlander Nokton 58mm f/1.4 SL-II
• Voigtlander Ultron 40mm f/2 SL-II
• Sigma 30mm f/1.4 EX DC HSM
• Nikon 50mm f/1.4G AF-S
• Nikon 85mm f/1.8D AF
• Sigma 50mm f/1.4 EX DG HSM
• Tamron SP 60mm f/2 Di II 1:1 AF Macro

These lenses can AF on your D40X body.
These lenses won't AF on ANY Nikon body.