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DSLR eyepiece projection?


riogrande100
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Last night i looked out and finally saw the Orion nebula for the first time. Considering i live in a light polluted area, and using only a 5" reflector it was very clear but not much color. I was looking through a 25mm eyepiece, however when i switched to my DSLR using only a 2x bader and the scope as prime focus i saw nothing.

Is there anyway of using a 25mm eyepiece and the dslr combined?

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Last night i looked out and finally saw the Orion nebula for the first time. Considering i live in a light polluted area, and using only a 5" reflector it was very clear but not much color. I was looking through a 25mm eyepiece, however when i switched to my DSLR using only a 2x bader and the scope as prime focus i saw nothing.

Is there anyway of using a 25mm eyepiece and the dslr combined?

Did this last night myself - but just prime focus, set camera to focus on Betelguese then goto'd to orion - not much on the live apart from 2-3 stars...but recognising these I new I was there...

It takes 2-3 seconds to show the first bright parts of the nebula - and after 30 seconds the image was pretty stunning...

Problem with Live view - is that it is grabbing frames and not actually able to preserve the frame for any length of time to see the nebula....

Chris

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Firstly, don't expect to see colour in things like M42. I've heard that under great skies and with a big scope you can make out colour in M42. As Chris says, you need a fair few seconds to start getting the Nebula to show up on the camera, you won't get it on live view. Also, whilst the Barlow being a x2 effectively doubles the focal length of the scope, it quadruples the exposure time, so whilst say 15 seconds without might be sufficient (I'm not saying it is... :) though) with the barlow, to achieve the same equivalent exposure, you'd need to expose a shot for 1 minute.

As for hooking an SLR to an EP for EP projection, I have done it using my Baader Hyperions, but there's a special attachment for doing that. It's also hard to get decent focus etc.

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Firstly, don't expect to see colour in things like M42. I've heard that under great skies and with a big scope you can make out colour in M42. As Chris says, you need a fair few seconds to start getting the Nebula to show up on the camera, you won't get it on live view. Also, whilst the Barlow being a x2 effectively doubles the focal length of the scope, it quadruples the exposure time, so whilst say 15 seconds without might be sufficient (I'm not saying it is... :) though) with the barlow, to achieve the same equivalent exposure, you'd need to expose a shot for 1 minute.

As for hooking an SLR to an EP for EP projection, I have done it using my Baader Hyperions, but there's a special attachment for doing that. It's also hard to get decent focus etc.

whats the special attachment? do you have a link for this?

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Eyepiece projection is not a good idea for deep sky exposures which are very faint as the exposure time doubles or even quadruples to get a decent image. For deep sky imaging best to use direct connection (prime focus) of the camera to the focuser without any barlows or eyepieces in the way. As exposure length increases so does the requirment for accurate tracking, unless your mount is driven and correctly polar aligned exposures longer than 1-2 minutes will show trailing and elongation of stars.

Best to stick with prime focus and exposures of say 30 seconds to start with and crop the region of interest from the image, with the two scopes listed in your signature 102mm (assume refractor) and 5" Newtonian you will have too small a field of view to fit the whole nebula in if you use barlows or eyepiece projection, give it a go at prime focus first.

Brendan

Edited by brendant
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Thanks Brendant, does anyone know any good articles or guides to move the mirror up the tube? As with the 5" newtonian i can't use it for prime focus without barlows. I then take it with moving will need to collminate.

On a side note the view of the nebula on the newtonian was pretty awesome and got a lot of the nebula in with a 25mm eyepiece.

I am a fan of DSO photography and the moon. The most suprising thing is that when i panned the scope i did see a really feint milkyway which suprised me considering how light pollution affects my skies.

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  • 1 year later...
  • 1 year later...

I would like to add a comment. I have a Skywatcher ED80 and am using a Nikon D90 at Prime focus with no diagonal. Works fine but image of Andromeda is very small. I want to use my x2 Barlow but am unable to focus with a 3cm T adaptor or no adaptor at all. Can anyone suggest a suitable T adaptor for use with the Barlow as I think the focus is further out than my 7.5cm focus range allows without the star diagonal?

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