Why is BKT Set settings grayed out on my D50 DSLR camera?

I have a D50 DSLR camera with a Nikkor 18-135mm Lens. I want to turn on the "BKT set" function but the option is grayed out and won't let me access it to turn it on. I went to CSM/Setup Menu and changed it to "Detailed". Any ideas why the BKT function is not accessible?

Dowloading my pictures from my camera onto the computer?

My camera is a Nikon D3100. Can you please tell me what i have to have and step by step what to do to download my pictures from my Nikon onto my computer? Please help!

Added (1). I have the newest generation of an Apple computer btw

Nikon D3100 Problem with Photo color?

I just bought my nikon D3100 and well everything is fine on the camera. When I shot photos, the color are amazing even when I zoom. However, when I upload them on my pc… It's not what I was waiting for. It's less colorful and truly not the same as on the camera! Why? Am truly disappointed.

How to adjust depth of field on a Nikon d5000?

Like this:

i'm a beginner at photography so i need help with step by step

thanks!

Added (1). No explanation on what depth of field is, just step by step instructions please. Like 1st change setting to a and then on the menu go to 'this' and select 'that' and so on.

Need info on lenses for DSLR cameras?

I got a Nikon D5000 about 6 months ago with an 18-55mm lens… Looking to upgrade to a bigger lens but know virtually nothing about the different ones out there… First off, what is the point of a lens such as a 50mm, like that have only one focal length? Also for all you more pro photographers out there, would you prefer, for instance, an 18-200mm or getting an 18-55mm and 55-200mm separately? And would I need one as big as up to 300+ or is 200 or so good? Any info about these lenses is greatly appreciated.

Added (1). Let me add that I'm an amateur but super enthusiastic about going pro. Mostly interested in photographing people, especially kids & babies. Also, I meant to ask what some of the letters mean in the lens descriptions such as AF-S Nikkor 50mm f/1.8G.AF is auto focus, correct? What about the -S? The f/? And the G? Also some are VR (vibration reduction) and some are not? When would the difference be noticeable? What about ED or just D @ the end of a description? DX? Thanks again, have already gotten all super awesome answers!

Added (2). Oh and what is the difference between 50mm f/1.8 and 50mm f/1.4? I notice the 1.4 is pricier…

What is a diopter setting in viewfinder?

I wear glass power of -2 but nikon d5000 has setting of -1.7 so is this a problem

with diopter can i use viewfinder without glass or what. Can i use an external 3rd party viewfinder in nikon camera what is the price

I can't access SELF PICTURE CONTROL on my Nikon d3100 due to current settings?

What settings might be affecting this

What is the purpose of uv filters?

I recently got nikon d90 and people have told me get an uv filter but i can't quite understand it's purpose. Can somebody please tell me the advantages of having an uv filter and also what will happen to my camera if i don't have an uv filter.

Class 6 or Class 10 for Nikon D3100 DSLR camera?

Would a Class 6 SDHC card be ok or would it be way better with a Class 10?

Can you use any memory card for SLR camera's?

If you were purchasing a SLR Camera could you use a normal cheap Transcend Memory Card or would you need a special type of memory card. I wondering this because I'm buying a Nikon D3000 on amazon and it said items frequently brought together then it said Lexar Memory Card but the problem is that it is 16 bucks! For only 8 gb can I use Transcend Memory Card's?