Exposure times with Lunt scope

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mstriebeck
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Exposure times with Lunt scope

Post by mstriebeck »

Hi,

I want to take images with my Lunt scope and PointGrey camera (Grasshopper3). Will I also need to adjust exposure times here? During totality, will I be able to see / image more details of the corona (if I expose longer)?

Any pointers welcome!

Thanks
Mark


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Re: Exposure times with Lunt scope

Post by Montana »

Hello Mark, a very warm welcome :hamster:

Is your Lunt scope CaK, Halpha or white light? are you expecting to image the partial phases through it?

If you are using a filtered telescope during the partial phase then the exposure will not change at all. You will still be imaging the sun but the area of the Sun will decrease in size. This exposure will remain the same whilst any part of the sun is present, even a small slither. At the point of totality the moon will completely obscure this surface and you will only see the moon. So through a filtered scope it will be black and you will see nothing.

At the point of totality you need to see it unfiltered to see the corona, apparently it is as bright as the light of the full moon. There will be no solar surface, only the pearly corona. At this point you need to take images without a filter and you will need fairly long exposures for the full extent of the corona but shorter exposures for the inner corona and prominences. Remember prominences were first spotted during a solar eclipse through unfiltered telescopes.

Here is a guide to help pick exposure times for your set up
http://xjubier.free.fr/en/site_pages/So ... osure.html

I hope this info helps, if you have any more questions please don't hesitate to ask. But remember, keep time of totality, as soon as the sun reappears you DO NOT want to be looking down the telescope unfiltered!!

Alexandra


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