I just got my Remote control in the mail for my Nikon and was excited to start doing star trails, I know most people layer shots of 5-10 minute incs. but regardless my bulb mode automatically stops at around 15 minnutes. I was wondering if this is normal? Just confused since I thought in bulb mode you are at 100% control of it.

I have read about bulb mode a little bit, and I realized that people that can do 30 minute exposures usually have their camera plugged in somehow to a power generator? I probably have it wrong. But the thing I got from it is that if you want to go much longer, you have to remember that 15 minutes of shutter being opened, it takes 15 minutes to record to the memory card. So that's a total of 30 minutes. I could be wrong though, maybe it depends on the camera, battery etc.

I know that it sucks up a lot of battery power, perhaps your battery died in 15 minutes?

This post was edited by Chantal7 on Jan 6 2011 01:36pm

its a problem with your memory card, its write speed is too slow and your memory buffer can only handle 15 minutes of exposure

you need to buy a faster card.

scandisc extreme pro or something like that

It will suck battery down loads as people said. It will take the camera the same amount of time the exposure time to process the shot after the shutter releases. It is a good idea to plug up to a power source while doing such long exposures. Also there is a way to get around the 30 minute cap for bulb setting. I would not recommend doing so, as you could easily break something.

My Sony A300 sat with 1 battery on bulb, open for half an hour, still had over had the battery left.

I'm not sure about nikon.. But none of my canon cameras has had that problem (inb4canonvsnikon).

I've taken long exposure shots that last over 90minutes. Any recent DSLR's battery wouldn't have any trouble handling it (if the battery is still in good condition and holds a charge).

Also, about it taking 15mins to record a 15min exposure.. it's true to a degree but that only applies when you have the setting "long exposure noise reduction" enabled in camera.

As the memory card buffer issue.. i don't think that's a problem o_O

Mad coz Canon has better batteries?