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DSLR photography for the upcoming eclipse

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#51 leveye

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Posted 04 July 2017 - 01:59 PM

if the lens doesn't come off the camera (most all P&S cameras), then the only thing you can do is 'eyepiece projection' where you use an eyepiece *and* the camera lens.  this works best with camera lenses that have a rather small front element, set for a medium to slightly wide zoom and mounted in front of the eyepiece just about as far as your eyeball would be.   all the rules for exposure go out the window, so its usually simplest to use trial and error to get the right exposure, and focusing a rig like this can be pretty tricky, especially if the camera has no provision for manual (or fixed infinity) focus.   If you can lock the camera in 'infinity' focus, then use the telescope focuser in 'live view' mode to focus.

Depends on the camera really. Some PnS cameras like a Canon G series have a bayonet mount and can easily use adapters and be used at "prime focus" with a telescope with the tele lens all the way back. Ebay has quite a few solutions albeit some are a bit pricey. Still better than eyepiece projection just IMHO.


Edited by leveye, 04 July 2017 - 02:00 PM.


#52 pierce

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Posted 04 July 2017 - 02:06 PM

yeah, the G series was why I said 'most all' and not 'all'.   



#53 leveye

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Posted 04 July 2017 - 02:12 PM

yeah, the G series was why I said 'most all' and not 'all'.   

"if the lens doesn't come off the camera (most all P&S cameras), then the only thing you can do is 'eyepiece projection'"

 

There are universal clamps and brackets now for most any PnS to be connected at prime to a telescope.It can be done without having to do EP. Again they are all over Ebay and Amazon. Just sayin not hatin. Be well!



#54 pierce

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Posted 04 July 2017 - 02:28 PM

if the camera has a lens, you have to use an eyepiece, and if you have an eyepiece and a camera lens, its eyepiece projection...    those clamps clamp onto said eyepiece.

 

prime focus implies the primary objective (lens or mirror) of the telescope is putting an image directly onto the camera sensor without any lenses in the middle (other than perhaps a barlow which is often necessary to achieve focus).



#55 Uzelessknowledge

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Posted 04 July 2017 - 04:26 PM

I was having thoughts of doing a time-lapse at around 300mm (I think).
Would you use a ball head or setup a mount and track?
I was going to setup my Orion Sirius and use my Canon 80d with 150-600mm lens, but the more I ponder the questions come up; do I need to set up the Sirius?
I'm thinking for time-lapse, even with the short exposure, it will be more fluid if I track and be hands off.


Travis
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#56 pierce

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Posted 04 July 2017 - 04:41 PM

I'd go with the tracking mount, as otherwise, the sun will pretty quickly drift through your timelapse field of view.


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#57 Billflyer

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Posted 06 July 2017 - 01:52 PM

 

I am looking for information about the relationship of lens focal length to shutter speed, to avoid blurring of the moon. Specifically, for shots of the outer corona and earthshine.

 

I know that when shooting stars with a wide-angle lens (say, 28 mm) you need to keep the exposure under 30 seconds to avoid star "trails."  I will be using a 600 mm lens on a DX format camera, for an effective focal length of about 900 mm. What is the longest shutter speed I can use and not have noticeable blurring or movement of the moon's image?

900mm is too much to capture the outer corona just IMHO. You want to keep it in the 300-700mm range. I would set the rig up during the day with your filter/filters installed and practice. At 900mm it will need to be pretty fast. Under 1/250th and faster for sure. Have fun out there!

 

Hmm. You're right. I cannot capture the outer corona with such a long lens. There is still the "earthshine" phenomenon however. I am renting the lens, so it will not be available for much (if any) practice. So my question is still "What is the longest shutter speed I can use and not have noticeable blurring or movement of the moon's image?"



#58 leveye

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Posted 06 July 2017 - 02:19 PM

 

 

I am looking for information about the relationship of lens focal length to shutter speed, to avoid blurring of the moon. Specifically, for shots of the outer corona and earthshine.

 

I know that when shooting stars with a wide-angle lens (say, 28 mm) you need to keep the exposure under 30 seconds to avoid star "trails."  I will be using a 600 mm lens on a DX format camera, for an effective focal length of about 900 mm. What is the longest shutter speed I can use and not have noticeable blurring or movement of the moon's image?

900mm is too much to capture the outer corona just IMHO. You want to keep it in the 300-700mm range. I would set the rig up during the day with your filter/filters installed and practice. At 900mm it will need to be pretty fast. Under 1/250th and faster for sure. Have fun out there!

 

Hmm. You're right. I cannot capture the outer corona with such a long lens. There is still the "earthshine" phenomenon however. I am renting the lens, so it will not be available for much (if any) practice. So my question is still "What is the longest shutter speed I can use and not have noticeable blurring or movement of the moon's image?"

 

You mean to capture the moon's surface detail while during totality without the filter on? Depends on the aperture of the scope. Start at 1/60th and go slower from there up to about 1/8th. Sky and Telescope latest issue has an excellent article of tips on camera settings. Mr Eclipse's website as well.




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