What the heck is "BKT"?

[DKilla]

Hey, everyone, I've been shooting for my high school yearbook for a while and I have been using my own camera...I have a pretty good feel for it and everything, but there are still things that I need to learn about it, that being "BKT".

I'm using a Nikon N55, and right below the flash button there is a button that has "BKT" on it and what looks like to frames overlapping each other where the overlapping is darkened. I really don't know what this does...I was hoping that there would be someone a little more knowledgable of my condition.

[ken1953]

Hi DK...if it's the same as my Nikon CP8400, it means Bracket. It was recently explained to me so my description may be a bit naive. It's supposed to toggle Auto Bracketing on and off. As I understand Bracketing, it automatically stops your camera up one stop and down one stop, depending on your setup. Mine has the option of either 3 shots or 5 shots...
Hope this helps...I'm sure others can help better.
In the future, any direct questions about Nikon equipment can also be asked in the Nikon Forum or in this forum.
Good luck and good shooting.
Ken

[another view]

That's what it is, but on some cameras you can program it differently as well. There is an Auto Bracket mode on some cameras where the first shot is at the exposure as metered, the next is over by 1/3 stop, one after that at 1/3 under, etc. All of this stuff, at least on some of the cameras is programmable, including how many shots it takes, whether it's 1/3, 1/2 or whole stops, if it starts at underexposure and goes to overexposure, etc...

Usually when I bracket, I do it manually, by setting the exposure compensation (+ or -) as needed rather than taking a bunch of shots that I probably don't need.

[DKilla]

Yea, I'm still a little confused as to what it is. Could someone possibly give me a link to where I could read up on this?

[ken1953]

Hi DK...I don't know any links but will try to simplify this a bit. I ask any who have more experience to correct any misinformation I may give him.
Ok...Lets say you set up your shot perfectly. Then you shoot that shot. Now you want to bracket that shot. That means you want to overexpose the next shot by 1/3 of a stop (for example). So now...your shot is "perfect + 1/3 of a stop). Ok...now you want do the other end of bracket, which means you want to "underexpose" your next shot by 1/3 (for example). So now you have 3 shots. One perfect, one perfect +1/3 of a stop (overexposed), and one perfect -1/3 of a stop (underexposed).

You can do this all manually by adjusting your stops, but many new cameras have the "Auto BKT" (mentioned above) and/or a button with a +/- on it to help you do it manually without going into your settings.

This is where I get fuzzy...so I will leave this to some of the others to explain why you do this, better than I can.
Hope this clears it up a little.
Ken

[another view]

Here's some info. In-camera light meters can be fooled in some situations like snow. Meters will expect to see everything in more of a mid tone so it will tend to underexpose. If you see a scene like this where you're pretty sure that the in-camera meter's reading will be inaccurate then you'll want to change your exposure. For snow, I'd probably add +1 stop for starters.

But +1 might not be the perfect exposure, it could be +2/3 or +1-1/3. In this case, I'd probably shoot all three of these (+2/3 over the meter reading, +1 and +1-1/3). Shooting the different exposures this way is called bracketing. I wouldn't shoot at the camera's metered exposure because I know (just from experience) that this wouldn't be what I want.

The BKT function is auto bracketing and your manual will tell you how to set it up. The above is why you might want to use it. In my example, I'd first put in a +1 exposure compensation so my bracketing would be around that (set the BKT to -1/3, 0 and +1/3 and you'll wind up with +2/3, +1 and +1-1/3, hopefully you understand what I mean here).

There are a lot of reasons why you'd want to bracket and this is just one example. Some times you wouldn't have the +1 thing I was talking about, but it's probably the most common example I've run into in "the real world". Hope this helps...

[ken1953]

Here's some info. In-camera light meters can be fooled in some situations like snow. Meters will expect to see everything in more of a mid tone so it will tend to underexpose. If you see a scene like this where you're pretty sure that the in-camera meter's reading will be inaccurate then you'll want to change your exposure. For snow, I'd probably add +1 stop for starters.

But +1 might not be the perfect exposure, it could be +2/3 or +1-1/3. In this case, I'd probably shoot all three of these (+2/3 over the meter reading, +1 and +1-1/3). Shooting the different exposures this way is called bracketing. I wouldn't shoot at the camera's metered exposure because I know (just from experience) that this wouldn't be what I want.

The BKT function is auto bracketing and your manual will tell you how to set it up. The above is why you might want to use it. In my example, I'd first put in a +1 exposure compensation so my bracketing would be around that (set the BKT to -1/3, 0 and +1/3 and you'll wind up with +2/3, +1 and +1-1/3, hopefully you understand what I mean here).

There are a lot of reasons why you'd want to bracket and this is just one example. Some times you wouldn't have the +1 thing I was talking about, but it's probably the most common example I've run into in "the real world". Hope this helps...

Thanx AV...as a matter of fact...that is how Chunk explained it to me...but I was still to fuzzy to explain it to DK...hehe...Damn you PR guys and gals are good!!! and very helpful!!!
Ken

[another view]

Glad to help, Ken. Maybe I look at metering a little different (kinda "old school") than other people do, but for a good digital capture there's very little margin of error. It's a lot like slide film in this regard which is what I usually shot before I went with digital.

A lot of times I'll use a spot meter - either a handheld one or the one in the camera (that's my main complaint about Canon, many of their SLR's don't have them) and meter the scene how I want it to look. Pick the most important part of the shot and figure out how you want it to look. Point the spot meter at it and base your exposure on that. For example, I might meter a sunset in the sky right near the sun. I'll set that at +1 from the meter reading as my baseline exposure but might also bracket the shot at 1/3 stop over that. So, if I read 1/125 at f8 with my spot meter I'll use 1/60 at f8 (one stop over). I'll probably also shoot +1/3 which would be 1/50 at f8. Some people don't believe that bracketing should be necessary, but I'm there in good light conditions and set up so I'll decide later which one is better. If I don't shoot a bracket and only have one shot, then of course that's the best one I have...

BKT is just a way of automating this process. Like I said, I don't use it typically because I prefer to do a lot of this manually. Might be very helpful to some people and I'm sure it is because it's been a standard feature for years.

[DKilla]

It's all starting become a bit clearer, I really appreciate all of your help with my quarstion.