Camera Labs

Hi,

I would be going to North India in Jan 2012 and would get a chance to click some Himalayan views at night.

For this, I am planning to use ISO100, and exposures of around 15mins. I need to know:
1. Is there any risk of the sensor over-heating? What would be the maximum safe time for the exposure before it starts damaging my camera in any way? Also, how frequently canI safely do it? Do I need to give it a break in between two shots?
2. I would need to use a remote release for the exposures as to my knowlegde there is no way to keep the shutter open without continuously pressing the shutter button on my 550d. I just want to confirm that with the remote release, pressing it once starts the exposure and pressing it again ends it? Simply put, I wont have to keep the release button on the remote pressed for the complete duration of my exposure?

Also, if you have any tips/personal experiences of photographing in such conditions , please share.....

Sorry for the slightly lengthy post.....

Thanks,
Jinay

_________________
A picture is worth a thousand words, but a photograph should make you say just one - "WOW!"

Canon EOS 550D + 18-55mm Kit Lens + Canon 75-300mm III USM + Filters.
Panasonic Lumix FZ35

My Flickr: http://www.flickr.com/photos/jdm_01/

I have done almost an hour long hangouts on google+ with my 7D on ISO-800. It still lives and performs great, but it does indeed get jolly warm after such long exposures!
As far as I know the camera should have built in temperature sensors that will automatically shutdown the CMOS if it gets to hot.
I wouldn't be worried about it if I where you!

_________________
Canon 5D MkII -|- Sigma 24mm f/1.8 | Carl Zeiss 35mm f/2.0 | Canon 50mm f/1.4 | Canon 100mm f/2.8 Macro | Lensbaby Composer
Canon A-1 -|- Canon 28mm f/2 | Canon 35mm f/2.8 | Canon 50mm f/3.5 Macro

Hey, thanks a lot, Lorride! Could you also confirm if I am right about the remote release?

Thanks!

_________________
A picture is worth a thousand words, but a photograph should make you say just one - "WOW!"

Canon EOS 550D + 18-55mm Kit Lens + Canon 75-300mm III USM + Filters.
Panasonic Lumix FZ35

My Flickr: http://www.flickr.com/photos/jdm_01/

Pressing the button on a remote release will do the same thing as the shutter release on the camera. One press will open the shutter and close it again at the end of the exposure. Most remote release cables, if not all, have a bulb setting. When you press the button you simple slide it and it stays pressed down until you release it, and that's what you need to use
On the sensor overheat issue, I have done 1 hour exposures on my 600D without any problem. But the sensor does indeed get hot!

_________________
Canon DSLRs: 5D Mark III, 7D
Canon lenses: 17-40/4L, 24-105/4L, 24/1.4L II, 50/1.4, 85/1.8, 100/2.8L Macro, 70-200/2.8L IS, 100-400L
Other stuff: Canon Extender 1.4x II, Canon 580 EX II, Canon 430EX II, Velbon Sherpa 600R
Apple: MacBook Pro 15", iMac 27", iPad III, iPhone 4S, Apple TV

My deviantART

In stock form, no you can't keep the shutter open without depressing the shutter button if you're not using a remote shutter. However with the Magic Lantern firmware, which runs on top of the camera's existing firmware, you can set the shutter to be open for a set amount of time without having to depress the button constantly.

_________________
Bodies: Canon EOS 550D w/ Magic Lantern
Lenses: Tokina AT-X 116 Pro DX f/2.8, Canon EF-S 15-85mm f/3.5-5.6 IS USM, Canon EF-S 18-55mm f/3.5-5.6 IS, Canon EF 50mm f/1.8 II, Canon EF 70-300mm f/4-5.6 IS USM
Accessories: YongNuo Speedlite YN-468 Flash, Neewer Macro LED Ring Light, Meike Battery Grip, YongNuo RF-602 Wireless Flash Trigger & Receiver YongNuo WR-128 Wireless Remote Control

Cheap shutter cable from ebay, they all have a lock to hold it down for bulb. If you want to get fancy, there are ones with timers too. I've "only" used mine up to 4 minutes exposures without heat problems other than hot pixels.

_________________
Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.

shooting video with a DSLR will heat-up the sensor much more than long exposures,so you don't have a lot to worry about.

_________________
Gear: Nikon D80, 18-105mm, 35mm F/1.8, 85mm F/1.8, SB-600
Visit my work here

Thanks a lot for your responses, guys! It helps a lot.

My question is specefically with regard to Popo's mention of hot pixels. I am planning touse exposures of minutes with ISO100. But, I can obviously also use ISO200 and expose for half the time. Would doing so increase the noise a bit and have less hot pixels? Out of the two which is the preferred option? Which is easier to correct?

Thanks once again for all your inputs guys!!

Jinay.

_________________
A picture is worth a thousand words, but a photograph should make you say just one - "WOW!"

Canon EOS 550D + 18-55mm Kit Lens + Canon 75-300mm III USM + Filters.
Panasonic Lumix FZ35

My Flickr: http://www.flickr.com/photos/jdm_01/

Both are still going to be pretty bad I think. I'd have to suggest you try this out to get a feel for it.

Note, I'm assuming you will disable the camera's built in "long duration NR" as that will tie up the camera for huge amounts of time.

_________________
Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.

Thanks a lot popo. I'll try that out.

_________________
A picture is worth a thousand words, but a photograph should make you say just one - "WOW!"

Canon EOS 550D + 18-55mm Kit Lens + Canon 75-300mm III USM + Filters.
Panasonic Lumix FZ35

My Flickr: http://www.flickr.com/photos/jdm_01/