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Old 23-06-2022, 10:00 PM
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dugnsuz (Doug)
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Askar FRA400 400mm v's 280mm comparison

Hello all - Doug here, after a break of roughly a decade I'm back running head-first down the imaging rabbit hole again.


Like athlete's foot, you never really shake the bug (or the itch) do you!?


To make myself useful returning to IIS I thought I'd post a comparison of similar objects imaged with and without the specific 0.7x reducer for the Askar FRA400 f5.6 refractor - a very popular imaging scope these days.


The reducer brings the 400mm FL f5.6 default scope down to 280mm FL f3.9.


Prior to purchasing the reducer I might have found a side by side comparison useful, so I hope this helps someone else's potential decision.


All Ha images taken with the Askar FRA400 f5.6 Quintuplet refractor.
All single 900sec subs hot off the 2600MM, quick 'lick and a promise' with NoiseXterminator then posted below.




Image 1: NGC3576 @ 400mm f5.6
Image 2: NGC3576 @ 280mm f3.9
Image 3: Cat's Paw @ 400mm f5.6
Image 4: Cat's Paw @ 280mm f3.9


Apologies - the 280mm images were taken through incoming clouds - so those halos around the brighter stars have nothing to do with my lovely Chroma Ha 3nm filter (I hope)



I do like all that extra real estate the reducer affords - just need some good weather to use it.


All the best
Doug
Attached Thumbnails
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Click for full-size image (NGC3576-280mm.jpg)
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Click for full-size image (Cats-Paw-400mm.jpg)
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Click for full-size image (Cats-Paw-280mm.jpg)
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  #2  
Old 23-06-2022, 10:25 PM
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AstroViking (Steve)
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Hi Doug.

Welcome back to the rabbit-hole. :-)

That's an impressive change in the FoV for "only" 120mm change in focal length. Thanks for doing the comparison - someone will be sure to make use of it.

Cheers,
V
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Old 23-06-2022, 10:31 PM
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I am torn between the 400 with the reducer or the newer 300 the flat field is excellent in both images
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Old 23-06-2022, 10:45 PM
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Quote:
Originally Posted by Nikolas View Post
I am torn between the 400 with the reducer or the newer 300 the flat field is excellent in both images
I thought the ASKAR 400 was out of the budget range for you?
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Old 24-06-2022, 07:08 AM
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dugnsuz (Doug)
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Aberration inspector image (ASTAP) shows slightly elongated stars in the corners of the Reducer image (NGC3576) - certainly nothing that would make me want to toss it out the rabbit hole!
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Old 24-06-2022, 07:20 AM
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dugnsuz (Doug)
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Quote:
Originally Posted by AstroViking View Post
Hi Doug.

Welcome back to the rabbit-hole. :-)

That's an impressive change in the FoV for "only" 120mm change in focal length.

Cheers - yes, all that area around the Statue of Liberty nebula blew me away. Reducer will be great for those widefield Ha vistas


Quote:
Originally Posted by Nikolas View Post
I am torn between the 400 with the reducer or the newer 300 the flat field is excellent in both images

Decision, decisions! 400 gets you in a little closer and the reducer images don't appear to need surgical cropping of the edges either - my money's on the 400 (but I'm biased)


Quote:
Originally Posted by AdamJL View Post
I thought the ASKAR 400 was out of the budget range for you?
There's always Tuna bake while the credit card's getting paid off!!


Doug
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Old 24-06-2022, 01:32 PM
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I thought the ASKAR 400 was out of the budget range for you?
That's why I'm torn, I am renegotiating finances to see if I can do it but that means selling things I dont really want to sell.
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Old 08-07-2022, 08:18 AM
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Im happy with my FRA400. I have only used it at 280mm. The little telescope performs well with my ASI294MM and now with the larger ASI2600MM.

Sorting out a little bit of tilt when you are shooting at f3.9 can always be challenging.
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Old 14-07-2022, 09:34 PM
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Astronut07 (Ben)
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Gday

I definitely would be interested in purchasing one of these scopes.
Anyone on here know when the next shipment might be available?

Cheers
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Old 15-07-2022, 01:57 PM
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Gday

I definitely would be interested in purchasing one of these scopes.
Anyone on here know when the next shipment might be available?

Cheers
Testar are the Aussie distributors, if you contact them and put your email on their list they will let you know when they are coming in
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Old 15-07-2022, 02:15 PM
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Astronut07 (Ben)
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G’day Nik

Cheers mate have just registered interest

Thank you
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