Familiarity breeds contempt?

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Rusted
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Familiarity breeds contempt?

Post by Rusted »

Hi,

My late afternoon seeing improvement never materialised yesterday and there was even more cloud.
With an hour to go before dinner I turned the telescopes onto a distant house chimney lit by sunlight.
At 260 yards, checked by Google Earth, this unusual subject offered some very fine detail from my ADI174MM mono camera.
The Vixen 90mm f/11 is my usual white light instrument. The iStar 150/10 H-a my H-alpha weapon of choice.

I was shocked how much I learned about aperture, resolution, image scale, speed and sharpness of electric focusing.
Not to mention our familiar imaging software. All in a very short time too. Gain V FPS. Frame size, etc.
The effect on scale and exposure using GPCs. The sun offers little clue about scale once you are close up and personal.
My solar imaging has obviously become more habitual than a constant learning experience.

For example: I hardly ever capture 16 bit SER in SharpCap when solar imaging.
Though I do save the ImPPG output to 16 bit .tiff. Yet I could easily see the difference in image quality!
AS!3 was great at freezing the finest detail from my 500/75 frame videos.
There was only gentle thermal and wind movement. Now hairline cracks became visible.
While ImPPG crystallized everything into unusable coarse grain even with default settings.

The sun is obviously a much more forgiving subject than my distant chimney.
I had to reduce focusing speed to an absolute crawl to find the sharpest focus.

Try a terrestrial subject with your instruments if you can. You might learn something.
Fortunately my PST mod is easily stripped of all the H-a filtration.
The Vixen 90 just needed the wedge swapped over to a star diagonal.
The image from the 90mm on my 27" hi-res monitor looked nicely sharp.
Until, that is, I plugged the camera into the 150mm. Wow! ;)

The last image was taken from only 10 yards away with my G9 and Leica 50-200mm.
I needed to confirm the identity of star-like [spider] cracks in the brick [arrowed.]
The small, cross head screws in the flashing were easily visible from 260 yards.

chimney 260 yards 90mm 16 bit ser txt.jpg
chimney 260 yards 90mm 16 bit ser txt.jpg (115.1 KiB) Viewed 249 times
chimney 150 f10 pf7 txt.jpg
chimney 150 f10 pf7 txt.jpg (122.11 KiB) Viewed 249 times
P1252800 rsz chimney txt.jpg
P1252800 rsz chimney txt.jpg (219.1 KiB) Viewed 249 times


http://fullerscopes.blogspot.dk/

H-alpha: Baader 160mm D-ERF, iStar 150/10 H-alpha objective, 2" Baader 35nm H-a, 2" Beloptik KG3,
Lunt 60MT etalon, Lunt B1200S2 BF, Assorted T-S GPCs or 2x "Shorty" Barlow, ZWO ASI174.
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Montana
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Re: Familiarity breeds contempt?

Post by Montana »

Very interesting!! it is a pity I have nothing far away to pick. I can't even set up my C11 finderscope as I have nothing that the C11 can focus on :(

I always prefer to use 16bit ser as I notice a big difference in WL processing. However with the ASI this cuts the number of frames by half, whereas the Grasshopper stays the same, pity ;)

Alexandra


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Re: Familiarity breeds contempt?

Post by Rusted »

Montana wrote: Sun Jul 25, 2021 11:09 am Very interesting!! it is a pity I have nothing far away to pick. I can't even set up my C11 finderscope as I have nothing that the C11 can focus on :(

I always prefer to use 16bit ser as I notice a big difference in WL processing. However with the ASI this cuts the number of frames by half, whereas the Grasshopper stays the same, pity ;)

Alexandra

Thanks Alexandra. :bow

You need a two storey observatory. :D

Even then I have only a very narrow view to the south at low elevations. :roll:


http://fullerscopes.blogspot.dk/

H-alpha: Baader 160mm D-ERF, iStar 150/10 H-alpha objective, 2" Baader 35nm H-a, 2" Beloptik KG3,
Lunt 60MT etalon, Lunt B1200S2 BF, Assorted T-S GPCs or 2x "Shorty" Barlow, ZWO ASI174.
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