29 replies to this topic

[TareqPhoto]

So what do you think it is in this petzval's case? Considering there is a significant difference between a 585 and 571 sensor, I am curious what your thoughts are as to what the results are.

No thoughts, just few comments somewhere where people had issues with what we called "Petzval" scope, i think it was the Quad type, so i wasn't sure if all Petzval without calculation of back focus will natively give super stars shape with whatever sensor size being used, I have a Quintuplet, and i read someone [maybe out of thousands] didn't like it much for stars by edges, so i was thinking how he can solve that then, by using a corrector [flattener] when it is already have one integrated???

[NDWUDZ247]

No thoughts, just few comments somewhere where people had issues with what we called "Petzval" scope, i think it was the Quad type, so i wasn't sure if all Petzval without calculation of back focus will natively give super stars shape with whatever sensor size being used, I have a Quintuplet, and i read someone [maybe out of thousands] didn't like it much for stars by edges, so i was thinking how he can solve that then, by using a corrector [flattener] when it is already have one integrated???

Oh I see. Well, in my case I like this quintuplet Petzval design based on the sensors I use. I however am still puzzled having to add spacers to achieve focus. I thought the whole point of a petzval was so you could just attach your camera and adjust the focus knobs until everything is in focus. Unfortunately the 75Q doesn't have enough focuser travel to be able to do so.

[ScuseMeWhileIKissTheSky]

NDWUDZ247, I'm seeing your comments about focus on the 75Q.  It's possible you are missing attachment of a supplied piece when shooting at the native 404mm.  You should not need spacers for your 2600, at least I do not (mine is the first RisingCam version, mono.  I had a similar issue when removing the reducer, couldn't get focus (bottomed out I think on the "near" end.  I realized I had not attached a screw-on piece that was included with the scope and it adds roughly 20mm.  You should have either this piece, OR the reducer attached.  Hope that helps.  The scope is designed to focus without spacers at native FL, or typical 55mm spacers with the reducer.

 

Paul

[NDWUDZ247]

NDWUDZ247, I'm seeing your comments about focus on the 75Q. It's possible you are missing attachment of a supplied piece when shooting at the native 404mm. You should not need spacers for your 2600, at least I do not (mine is the first RisingCam version, mono. I had a similar issue when removing the reducer, couldn't get focus (bottomed out I think on the "near" end. I realized I had not attached a screw-on piece that was included with the scope and it adds roughly 20mm. You should have either this piece, OR the reducer attached. Hope that helps. The scope is designed to focus without spacers at native FL, or typical 55mm spacers with the reducer.

Paul

Thanks Paul. I'll have to look into that. Since I wasn't using the reducer and didn't need to add anything to be able to attach my imaging train, I did not believe I needed to check the box for any supplied attachments. Thanks again.

[NDWUDZ247]

I actually ran across "lost" test data collected with the 75Q. It was captured using an Antlia Quad-Band. The image was a stack of 14 x 177.395 second subs. I may have been heavy-handed dealing with Alnitak while processing in Pixinsight...lol

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