Astrophotography and Mirror Lock Up

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karlyh

New member
I'm wondering about mirror lock up..... I don't get a lot of info by manual about this, how, when and why its used. I could google it, but to be honest, I'd rather have it explain in general terms that I can comprehend. :rolleyes:

Thanks in advance

Oh.. and I'm asking about this along with astrophotography because of some vague advice I was given about what was needed for astro shots. Tripod, remote etc.
 
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goz63

Senior Member
What advice did you receive on astrophotography shots? Locking the mirror up will reduce the vibration when doing very slow shutter speeds so that the minute vibration of the shutter moving won't cause blurred picture. Longer exposures are used along with a tripod. Some people use the remote as this will reduce the vibration caused my pressing the shutter release also. The D90 has an exposure delay feature that will help with this. I don't have a D40 so can't comment on your camera. The D90 also can't lock the mirror up for anything except cleaning. Hope this helps...
 
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karlyh

New member
2:30am here so bare with me..lol Um.. it was a quickie comment from commentors on Facebook/Nikon page... I asked there but didn't get a response... One of those posts where 60 comments go by within minutes.. Anyway, that is what I was thinking that my D40's Mirror Lock was good for as well. And I really had the idea of what you've explained here but wasn't absolutely sure. I use a tripod and remote while trying my hand at sky shots...Also, I seen a comment about lower end camera's running the risk of sensor burn, which I'm assuming the D40 falls in that 'lower end' category... Is this something I should be concerned about, do you know?
Thank Mark... much appreciated
 
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goz63

Senior Member
I am not sure I would consider a D40 a "lower end camera" in any case I have not heard about sensor burn. My gut feeling is that if you were shooting a brighter light and held the sensor open you could damage it but I would not think that taking night or astro pics would cause this problem. I would seem to me that if that was the case there would be a lot of internet chatter on it and I have not seen that. Have you started to take some astro pics? Have you had any problems with blurred pics? If you were looking for an investment to assist you I would consider a remote release, whether wired or wireless. That should help you as much as the "mirror lock up" IMHO
 
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Essence of Imagery

New member
I know exactly what you're talking about Karlyh. It might be an issue on the consumer-level cameras, and I know it's most certainly (wife has pics to prove it) an issue on the Nikon D80. It's not a "sensor burn" per se, it's actually the build-up of heat on the sensor from the electronics around it. With long exposures (think 3 or more minutes) the electronics in the camera tend to heat up - and the heat dissipation in the compact camera bodies isn't sufficient to avoid this.
The issue causes a purple-ish "burn" of your image in a "vignette-ish" style around the outer edges of your images. It's nothing that (so far) has shown any damage to the camera itself, it works perfectly fine under regular shooting conditions, it just doesn't like sitting with the sensor gathering light for too long.

My D300, on the other hand, I've set it out on the back porch and done 1hr. + long exposures, one right after the other, and it doesn't have the heat issue.

More information here: DPanswers: Defects
 
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