[deaning]

I was getting into long exposures after learning how to calculate them properly and got a 2hr 20min with my K5 last year and then was told you can fry the sensor. A member of our club then said he had done just that to his Nikon during a 4 hour exposure. I know image stacking is an option but for my projects I prefer a single exposure (light painting). So any ideas as a goof safe margin, an hour, two? There was no damage to my K5 but I now have a K3 and do not want to risk damage.

[pixie]

Hm, that is a very good question. I have tried a few long exposures shooting star trails, all less than an hour, without any problems with the K5. I remember reading that the sensor can overheat, though. I look forward to what the gurus have to say about this. Would it be stupid of me to think that the cam would shut down if the temp was getting too high? The chip could have some algorithm written into it to protect the sensor. Perhaps based on how much power it's using....

Edit: Checked the manual on Bulb Mode, no warnings are given...

[calculator01]

Just some observations...


I have had my K-r get hot to the touch over shooting several half minute shots back to back, in winter weather. If I recall, it flashed me a warning before not wanting to turn on. So yes, it turned itself off.

[pixie]

Good to know it's got it in there...

[Dr_who]

I think it depends on what your imaging. If you point it to the sun and are just leaving the shutter open it'll potentially have issues. Where as I've done 8 minute exposures for over 90 minutes at night and had no issues at all. I would think the camera itself would turn off if there was any heat related issues from overuse.

[RonHendriks1966]

The camera will shut down in case off overheating, there is a warning in the camera. So as your environment is not to hot, there would be no problem.

[DeadJohn]

Small tangent about damage: Direct sunlight or lasers can damage the sensor even on a short exposure.

[promacjoe]

The life expectancy of any sensor under these circumstances cannot be determined. The damaging effects under these conditions is accumulative. This means that you may not see any damage from doing this for the first hundred or even thousand exposures, eventually you will start seeing dead pixels or the sensor might die completely. Once your sensor starts getting hot to the touch It's life expectancy gets shorter. Over the years there have been several articles placed on the web about using digital cameras for Astrophotography. Having read only a fraction of these articles I have come to the conclusion that the best way to limit the damage is to limit the exposure time and give the sensor time to cool between exposures. Layering exposures is the best way to protect your camera.

Remember if your camera gets warm, You have probably damaged your sensor, even though you do not immediately see it.

Stay safe and have fun.
Joe.

[FrankC]

Sounds like if you're doing some serious long-exposure work, having two or more bodies could be beneficial. Shoot a frame with one body and switch to another while the first one cools off.

[Learjet]

Now you tell me....

Astrophotography is 99% of my photography these days. I haven't killed a camera yet, but now that I have autoguiding setup, the exposures will be getting longer, probably to 10 minute max.

[Lowell Goudge]

Something to think about but I believe starting with the K7 where live view and video mode came in the sensors have been designed and cooled differently. Remember the K7 and K20 have essentially the same sensor, but one of the changes was to have the K7 optimized for video, because video runs the sensor full time!

I think today the sensors on most cameras, especially those which are video capable we expected to be on lperminantky. Video can be on for more than 10'minutes at a time and I am certain the thermal time constant of the sensor to its heats ink is In the range of seconds not minutes. The overall camera will, of course take longer.

[fryad]

I am now very nervous having come across this thread! I bought a B&W 3.0 ND 100x filter a few months ago and took some great long exposure shots getting cloud movement over a gloomy city. I great way to enliven dull shots.


Since then though I get foggy areas, overall low contrast, colour casts and a strange line across the lower third with a purple cast (see attached). This happens now on every shot I take over 15 secs long in daylight with the filter on. So I bought a Hoya for another lens and tried it with the same result. This is on my K30D. I have run the same experiment on my K20D and both lenses and both filters work as they should. Have I fried the K30D's sensor? Any help would be much appreciated. Thank you.

[mtux]

That's a cool effect for the photo I reckon.
Sorry, I have no idea about the issue, but have used my K30 for more than 1k seconds with no issue.

[DeadJohn]

I am now very nervous having come across this thread! I bought a B&W 3.0 ND 100x filter a few months ago and took some great long exposure shots getting cloud movement over a gloomy city. I great way to enliven dull shots.

Since then though I get foggy areas, overall low contrast, colour casts and a strange line across the lower third with a purple cast (see attached). This happens now on every shot I take over 15 secs long in daylight with the filter on. So I bought a Hoya for another lens and tried it with the same result. This is on my K30D. I have run the same experiment on my K20D and both lenses and both filters work as they should. Have I fried the K30D's sensor? Any help would be much appreciated. Thank you.
Attachment 234189

That looks more like an optical issue rather than the sensor. A bad row on the sensor would give a very crisp line, while the horizontal bright line 2/3 of the way down your photo looks fuzzy. Light leak through the viewfinder or elsewhere? Shutter malfunction?

Try several 30 second exposures with the lens cap on. Take one in a dark room to confirm the sensor isn't falsely detecting light. Take another in bright sun or under a bright lamp, shifting the camera during exposure to get light hitting every nook and cranny of the camera, to rule out a light leak.

[Fogel70]

I am now very nervous having come across this thread! I bought a B&W 3.0 ND 100x filter a few months ago and took some great long exposure shots getting cloud movement over a gloomy city. I great way to enliven dull shots.


Since then though I get foggy areas, overall low contrast, colour casts and a strange line across the lower third with a purple cast (see attached). This happens now on every shot I take over 15 secs long in daylight with the filter on. So I bought a Hoya for another lens and tried it with the same result. This is on my K30D. I have run the same experiment on my K20D and both lenses and both filters work as they should. Have I fried the K30D's sensor? Any help would be much appreciated. Thank you.
Attachment 234189

Make sure to put on a cover on the OVF when doing this type of shots.
It's a big risk that light entering OVF can affect the exposure, especially when using ND filters during day time.