How long can a "bulb" exposure last on a Nikon D80?

Question

How long can a "bulb" exposure last on a Nikon D80?

Answer 1

If you buy a remote shutter release, you can lock it open for as long as you like.   Some of shots I have made are over three hours.  I do this when I am shooting star trails.

Answer 2

Until your finger gets sore and you let go of the button!

The better question may be what is the longest useful exposure you can achieve with bulb... I haven't tried it myself, but I think after a couple of minutes there will be so much noise accumulated, that you will not be left with much anything useful.

This is not just a problem with D80, it's an issue with all digital cameras currently on market. The more expensive bigger ones (especially with full frame sensors) perform better in that department. D80 is a lot better in this than most P&S cameras, which will usually start turning in bad noise levels after just a few seconds.

So the bottom line is - you can expose for as long as you can hold the shutter release, but to get anything useful, I'd keep it down to a minute or two at the max.

LEM.

Answer 3

Both LEM and fhotoace are right, but let me offer a more complete answer.

As mentioned, a bulb exposure will last as long as you hold the button.  To make it easier, there are shutter release cables that have a lock.  

There is another limiting factor that hasn't been mentioned yet.  That being battery power.  To get some of the really long exposures, you either need a battery grip with two fully charged batteries or the Nikon EH-5 AC adapter.  Obviously, an AC adapter doesn't work well out in the field, but it works great outside your house on the patio, assuming you don't live near the city and have power outlets on your patio, etc.

I've also done exposures that lasted for a few hours.  Even on a Canon 20D, I didn't get a whole lot of noise, so I would assume your D80 is quite capable of taking a really long exposure without getting much noise.  But then again, it depends on what you're going for.  As LEM suggested, not all really long exposures are going to produce something useful.

Another thing you might find useful is the Nikon MC-36.  I have the Canon version of the timer remote and it is great.  I can dial in that I want a 20 minute exposure and not have to remember to release the lock after 20 minutes.  For doing bulb exposures (especially really long ones), this is a must have accessory.