4 minute shutter?

[Artisticmind]

Hey, I was interested in taking some astronomy pictures, but after reading some tips some people were talking about they used liek nineteen 4 minute exposures.... How is this possible because i thought most cameras were only up to 30 seconds shutter speed?

his is my first effort at star trails using my 350D and 17-55 kit lens, think the exposure was about 30mins.

These were 20 4 minute exposures for a total of 80 minutes, 55mm, f/5.6 800 ISO.

I searched these forums and looked online and found things like interval timers, stacking techniques and what not, but that doesnt explain the 4 minute exposure. How can i get crazy long exposure times like that? Are they in fact using modded hardware or what?

Sorry for being a n00b, what did I miss?

Thank you for your advice.

[LostShootingStar]

you can put it on "bulb" mode, and it basically stays open forever. http://m08o1124znfu179.imageshacknow.info/img/2465/o09a0208gstn/POTNsmile.gif

[ssracer]

Ditto on Bulb. It will stay open as long as the shutter release is held down.

What camera are you shooting with?

[Adrena1in]

All you need is a remote shutter release, then put your Camera into "M" mode and set the exposure to "Bulb". Press the shutter release button and the shutter opens. Release the button and the shutter closes. Remote shutters usually let you lock the button, so you can open it, lock it, then go indoors and have a cup of tea while the camera soaks up all those photons that have travelled across space for millions of years.

[Artisticmind]

Ok duh,

well I used to shoot with a 350d, but never really used bulb. I guess I will be getting a remote control. I will try it when my new 450d comes in

Thanks guys, sorry for such a simple question.

[ssracer]

No apologies necessary. That's how we learn :D

[Adrena1in]

I will try it when my new 450d comes in.

Nice, it's a good camera and the Live View option will help loads with focussing on stars. ;)

[hollis_f]

Ok duh,

well I used to shoot with a 350d, but never really used bulb. I guess I will be getting a remote control. I will try it when my new 450d comes in
When you get a RC I'd recommend getting one of the cheap chinese ones from Ebay. Much cheaper than the Canon one and works just as well. In fact you can buy a nice wireless RC for the same price as the Canon Wired one.

[artyman]

I bought a cheap wireless remote on eBay a while back and it works fine. Not used it for a long timed shot yet, it doesn't have a lock position so would need to keep it depressed.

[hollis_f]

I bought a cheap wireless remote on eBay a while back and it works fine. Not used it for a long timed shot yet, it doesn't have a lock position so would need to keep it depressed.
The wireless RC I got from Ebay (Phottix Cleon) has a special 'B' mode - one press to start the exposre, another to end it.

[ssracer]

A lot of the wireless ones I have seen will go into B mode if you hold it down for like 2 seconds, then you can let go and press it again to end it. I need to get a wireless one, all I have right now is the Canon wired one.

[jacuff]

How can i get crazy long exposure times like that? Are they in fact using modded hardware or what?

Thank you for your advice.

I've got a couple of those expensive Canon remotes (TC-80N3) but there looks to be a good knock off of it from DealExtreme (http://www.dealextreme.com/details.dx/sku.13892). A timer remote like that is all you need.

Set your camera on a tripod. Set your iso and aperture to what you want. Set you shutter speed to bulb. (Some cameras this will be in M mode just past 30" and others Bulb is it's own place on the dial/Modes.) Then on the remote, you select Frames and turn the dial to 20. Then you go to Long and set it for 4 mins. Finally you press start. It will take 20 exposures of 4 mins each with no delay in between frames with no further interaction from you needed. Just sit and watch your camera. If you wanted to... you could program a delay between frames, or a delay before the first picture only.

People knock how expensive that remote seems, but it is really worth it.

[ssracer]

Nice remote, but looks like it will only work with the xD and xxD series cameras. The OP appears to have an xxxD series.

I would recommend a wireless remote for this just do there is no chance of the remote shaking the camera.

[jacuff]

Nice remote, but looks like it will only work with the xD and xxD series cameras. The OP appears to have an xxxD series.

I would recommend a wireless remote for this just do there is no chance of the remote shaking the camera.

It should be easy enough to modify. :)

http://www.camerahacker.com/Canon_Accessory/N3_E3_Convert.php

[Jeff]

I got a Phottix Cleon C8 Wireless Remote from TEAMSPEED in the classifieds thread. It can work both wired & wireless. Works great. He seems to get new batches from time to time. About $36 (US) as I recall.

[Artisticmind]

Thanks for all your help guys, I can't wait for my cam to come to try this all out.

[TuathaD]

Does anyone know how long an exposure the 1Ds MkIII can do at ISO 1600 before some of the dark pixels start to turn bright, as in making the final picture look like it has tiny, single pixel specks that are red or white in it even if it is a shot in the dark with lens cap on? These pixels are fully bright but disappear in shorter exposures.

Thanks!

[ssracer]

I would say it depends on the camera....hot pixels on the sensor