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IC348, NGC1333 and friends mosaic.


ollypenrice

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21 hours ago, ollypenrice said:

Yes indeed, very modest exposure time. But if we compare the RASA 8 with an 80mm refractor, which might be the alternative at this kind of FL, the RASA has (allowing for the central obstruction) 4.9x the light grasp. So 3 hours equates to 14.7 hours. Six panels later, that comes to an alarming 88 hours, as opposed to 18. On the other hand the stellar image quality, seen at full resolution, is not as good in the RASA as from a good refractor. But then, on the other other hand, the fast F ratio is stunningly good on separating nuances in the dust.

I'm really enjoying the RASA. It's brought a fresh approach to imaging for me.

Olly

Why I love mine so much and wanting to upgrade to a Rasa11 so I can add a filter drawer with the extra back focus the bigger Rasa has over the 8 when using a 2600

Edited by Catanonia
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1 hour ago, Catanonia said:

Why I love mine so much and wanting to upgrade to a Rasa11 so I can add a filter drawer with the extra back focus the bigger Rasa has over the 8 when using a 2600

I wouldn't regard the 8 to 11 as an upgrade so much as a change.  It works both ways: the 8 gives a wider FOV. On the other hand the 11, I think, will cover a full frame chip, restoring a lot of FOV. Call it an upgrade if you also change the camera...

Olly

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2 hours ago, ollypenrice said:

I wouldn't regard the 8 to 11 as an upgrade so much as a change.  It works both ways: the 8 gives a wider FOV. On the other hand the 11, I think, will cover a full frame chip, restoring a lot of FOV. Call it an upgrade if you also change the camera...

Olly

Yes you are correct. The main reason is the larger backfocus with the 11 compared to the 8 for me as it is a real PITA having to take the camera off to remove / add filters.  That and "bragging rights" :D

Edited by Catanonia
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23 minutes ago, Catanonia said:

Yes you are correct. The main reason is the larger backfocus with the 11 compared to the 8 for me as it is a real PITA having to take the camera off to remove / add filters.  That and "bragging rights" :D

You and me talked about it Cat. I can see the filter issue. But you really need a full frame APS sensor to make it worth while, or you only get half the FOV (and no more fotons collected). And then you need a big mount to carry the very heavy RASA 11. My Mesu200 would have no problem with that but I still went for a dual-RASA8 rig rather than a RASA11 (same light grasp). Maybe I rethink it one day, but a RASA11 with and APS-C sensor does not make much sense to me since I am after the big FOV.

Edited by gorann
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11 hours ago, gorann said:

You and me talked about it Cat. I can see the filter issue. But you really need a full frame APS sensor to make it worth while, or you only get half the FOV (and no more fotons collected). And then you need a big mount to carry the very heavy RASA 11. My Mesu200 would have no problem with that but I still went for a dual-RASA8 rig rather than a RASA11 (same light grasp). Maybe I rethink it one day, but a RASA11 with and APS-C sensor does not make much sense to me since I am after the big FOV.

Yes, a new camera would be in order to get the full benefit. This would be the next step when money allows. Rasa 11 and then a full frame.

I have an EQ8-r so mount not a problem

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