Astrophotography

[eugenep]

Bringer of bad news here.....

Firstly the idea that a CCD's life will be shortened by continious long exposures is utter rubbish. CCD sensors are the preferred sensor technology for professional astrophotography cameras which have operational lives of tens of thousands of hours per sensor. Many professional observatory cameras spend upwards of 10 hours a night imaging (30-180 minute exposure) for 200 plus days a year with zero ill effects to the sensor. Many of the cameras are used for 15-20 years between replacement.

Commercial CCD astrocameras from the likes of sBIG and CMOS cameras from Starlight eXpress etc often use the same sensors as DSLR's again with lifetimes of tens of thousands of hours. My KAF400 CCD chip based astrocamera has over 5,000 hours of imaging on it while my older TC245 has over 9,000 hours.

Pixels "dying" is caused by either manufacturing faults or mechanical issues, not by long exposure photography.

Ian

Thanks Ivan for sharing his knowledge with us. It really clear my doubt about using a DSLR for star trails. :thumbsup:

 

[Francis247]

Bringer of bad news here.....

Firstly the idea that a CCD's life will be shortened by continious long exposures is utter rubbish. CCD sensors are the preferred sensor technology for professional astrophotography cameras which have operational lives of tens of thousands of hours per sensor. Many professional observatory cameras spend upwards of 10 hours a night imaging (30-180 minute exposure) for 200 plus days a year with zero ill effects to the sensor. Many of the cameras are used for 15-20 years between replacement.

Commercial CCD astrocameras from the likes of sBIG and CMOS cameras from Starlight eXpress etc often use the same sensors as DSLR's again with lifetimes of tens of thousands of hours. My KAF400 CCD chip based astrocamera has over 5,000 hours of imaging on it while my older TC245 has over 9,000 hours.

Pixels "dying" is caused by either manufacturing faults or mechanical issues, not by long exposure photography.

Ian

Hi Ian,

This is absolutely good news. At least I can be sure that my dSLR can do star trails without having the fear of it getting spoilt.

But how about the high temperature due to long exposure and NR. I remember that it get really hot when I am trying out the star trails taking. Will that in some sense cause harm to my camera? Please advice. Appreciate that. Thank you.

 

[Ian]

Hi Ian,

This is absolutely good news. At least I can be sure that my dSLR can do star trails without having the fear of it getting spoilt.

But how about the high temperature due to long exposure and NR. I remember that it get really hot when I am trying out the star trails taking. Will that in some sense cause harm to my camera? Please advice. Appreciate that. Thank you.

Heat, now that's a totally different kettle of fish!

Dedicated CCD cameras for astronomy normally use Thermo-Electric cooling systems. Most common is a single stage Peltier cooling module, though some of the larger cameras use a dual stage Peltier cooling system. Professional grade cameras as used in the major observatories usually use Cryogenic cooling such as liquid Nitrogen.

The cooling is more to do with reduction of noise which increases with temperature.

Now to the DSLR. They are uncooled so you can expect in most consumer grade DSLR's some sigificant temperature rises and they probably will get warm to the touch. This shouldn't be an issue though, except it will lead to an increase in noise. Professional bodies (D2X, 1X, H series) shouldn't have this issue as they have far more metal in their bodies and larger capacity batteries etc. The D2X certainly doesn't run more than luke warm at 30 minute exposure levels.

My suggestion is that you measure the temperature rise on the camera body and if it's more than say 30°C above ambient temperaturethen it may be worth considering the use of a computer fan to provide air flow over the camera body.

Ian

 

[_espn_]

Hi Ian,

This is absolutely good news. At least I can be sure that my dSLR can do star trails without having the fear of it getting spoilt.

But how about the high temperature due to long exposure and NR. I remember that it get really hot when I am trying out the star trails taking. Will that in some sense cause harm to my camera? Please advice. Appreciate that. Thank you.

Time to shoot more, when can I tag along with you?

 

[yanyewkay]

Is this question confined to only Nikon camera in which you are considering. If so this is the correct forum to post if not then I will move it to General Tech Discussion as it is more appropriate there.

To the others keep this discussion to Nikon, unless the TS is asking for other brand too.

ya was refering to nikon bodies.

 

[Ian]

Thanks Ivan for sharing his knowledge with us. It really clear my doubt about using a DSLR for star trails. :thumbsup:

Ivan????? :think: :sticktong :flame: :flush:

 

[Francis247]

Heat, now that's a totally different kettle of fish!

Dedicated CCD cameras for astronomy normally use Thermo-Electric cooling systems. Most common is a single stage Peltier cooling module, though some of the larger cameras use a dual stage Peltier cooling system. Professional grade cameras as used in the major observatories usually use Cryogenic cooling such as liquid Nitrogen.

The cooling is more to do with reduction of noise which increases with temperature.

Now to the DSLR. They are uncooled so you can expect in most consumer grade DSLR's some sigificant temperature rises and they probably will get warm to the touch. This shouldn't be an issue though, except it will lead to an increase in noise. Professional bodies (D2X, 1X, H series) shouldn't have this issue as they have far more metal in their bodies and larger capacity batteries etc. The D2X certainly doesn't run more than luke warm at 30 minute exposure levels.

My suggestion is that you measure the temperature rise on the camera body and if it's more than say 30°C above ambient temperaturethen it may be worth considering the use of a computer fan to provide air flow over the camera body.

Ian

Hi Ian,

Thanks for sharing the info. Will check it out and see how it goes. Thanks for your advice.

 

[lsisaxon]

D2H, D2Hs, D2X and D2Xs can. And D2X/Xs can even set timing interval.

Hmm.. How come I didn't know that? :think:

Now I remember.. It seems that the bulb mode for D2X is not very useful because the long exposures are quite noisy.

 

[jimmyc]

ha ha that is funny :bsmilie:

Ivan????? :think: :sticktong :flame: :flush:

 

[lsisaxon]

FM better rite?? hehehe

Full mechanical

Yes. You just trip the shutter wait for the vibration to die down and forget about it until 1-2 hous later.

 

[Ian]

Yes. You just trip the shutter wait for the vibration to die down and forget about it until 1-2 hous later.

Not really, by the time you factor in compensation for film reciprocity failure you're better off with a noisy frame which can be cleaned up by the use of flats and dark frame subtraction.

 

[zac08]

Hmm.. How come I didn't know that? :think:

Now I remember.. It seems that the bulb mode for D2X is not very useful because the long exposures are quite noisy.

D200 also can set interval timing... but I still need to learn how to set it up correctly...

 

[yanyewkay]

Is this question confined to only Nikon camera in which you are considering. If so this is the correct forum to post if not then I will move it to General Tech Discussion as it is more appropriate there.

To the others keep this discussion to Nikon, unless the TS is asking for other brand too.

ya was refering to nikon bodies.

I think I sort of got my answer already. moving this thread to General Tech Discussion will benefit more people.

PE/Ian could you help me move this thread there? THANKS!

 

[zac08]

Not really, by the time you factor in compensation for film reciprocity failure you're better off with a noisy frame which can be cleaned up by the use of flats and dark frame subtraction.

Hmmmmm...:think:

darn, still gotta learn hoe to calculate this... haiz. :cry:

PS : Francis, do share with us on the heat issue (if any crops up)


Thanks,

 

[ipin]

D200 also can set interval timing... but I still need to learn how to set it up correctly...

or you can get the MC-36 remote. :devil: :lovegrin:

 

[_espn_]

ha ha that is funny :bsmilie:

Seeing you post is even more funny!

 

[zac08]

or you can get the MC-36 remote. :devil: :lovegrin:

Nah... I just got a 3rd party MC-30 equivalent... good enuff for my usage so far...

 

[ipin]

Nah... I just got a 3rd party MC-30 equivalent... good enuff for my usage so far...

But the MC-30 doesn't have the interval timer leh. get the MC-36, ok liao. dun need to upgrade liao. it can do everything that the cam can. :thumbsup: :heart:
D200 using a 3rd party cable release....you gotta be kidding, right?
:bsmilie: JUST KIDDING!

 

[lsisaxon]

Not really, by the time you factor in compensation for film reciprocity failure you're better off with a noisy frame which can be cleaned up by the use of flats and dark frame subtraction.

Well, yeah, you could but it just takes more effort. And it harder to get long long star trails. But digital is great for prime.

 

[_espn_]

Well, yeah, you could but it just takes more effort. And it harder to get long long star trails. But digital is great for prime.

Pro also into astrophotography?