barkingsteve

Not the best conditions but i recently cleaned the c925 and wanted to collimate. The moon was out and took the opportunity to take a few test shots. These are taken with a celestron 2.5x barlow and a 178 mono at bin 2 with a 642 ir pass filter. 

33 x 3 minute exposures ( gain 121, brightness 4  ) captured with an Ioptron GEM45, 8" F/4 Newt, 294MC pro with L-Extreme filter. Guiding with svbony 30mm guider and 178mm camera.  

Rather than the t shirt method, may i also suggest getting some light diffusion material like this:

https://www.amazon.co.uk/Seamless-Diffusion-Photography-Lighting-Modifier/dp/B019GSCJFA?th=1

and using some embroidery rings like this:

https://www.amazon.co.uk/Stitch-Embroidery-Plastic-Handmade-Crafts/dp/B08DR76MRD/ref=sr_1_92?dchild=1&keywords=embroidery+rings&qid=1635811700&sr=8-92

I stretched 3 layers of the material in between the ring though this can be a little tricky to get perfect at first, then trim it up. 

Very nice 👍

6 hours ago, neil phillips said:

Very Nice again Steve. Is the C9.25 New ? i wanted to try at 1.5 x times which is a optimal sampling rate for the equipment. But i cant get it to work just yet. So will have to wait.  Looks like your over sampled. Got some of my best shots being oversampled in the past. Yours are showing very good detail. Can see a little noise (Bottom shot) The one above is a lot better with less noise. You have got the detail out. Very cool.            

Hi Neil,

           Thank you   The C925 is around 3-4 years old, it is the ota from an evo 925. The evo mount stopped working properly about a year ago  i haven't collimated in a while and it is just a gnat's hair out, but...you know..... time collimating is time not imaging   I keep meaning to use the 178mm at bin 2 with the 2.5x  barlow, that should be close to optimal sampling but yeah, results are still fine when you oversample a bit and conditions are ok or better.

Thank you  Here are a few more along the terminator from the night, this was with the 294 and a 2.5x barlow.  I kept these desaturated.

2 panel mosaic with the C925 and 294MC pro with ir/uv cut. Mono shots with the 178mm and 642 ir pass filter.

Early Friday morning shot. best 50% of 2.5k  using C925 with the 0.63x reducer and 294MC pro with uv/ir cut filter. Stacked in AS3, sharpened in registax and processed with gimp.

7 hours ago, Zummerzet_Leveller said:

@barkingsteve a lovely image there, I'd love to know how you pulled out the colour in GIMP? I've been playing around with luminosity masks and can't seem to get much from the data.  I've seen the Photoshop tutorials using the addition of hue/saturation layers but can't fathom how to achieve similar in GIMP. Any insight would be greatly appreciated.

Hi Jody,

    It was the first time i had used Gimp for processing, i usually use PS    but if i recall it was just playing with saturation, hue-chroma and hue-saturation under the colours tab. You can individually increase the hue and saturation of certain colours under the hue-saturation tab which can be useful. I also never used layers, just the main image. I really do not have a set procedure, i just play with the sliders until it looks good to me   hope this at least helps a little.

Hi Mick,

            I have an old etx autostar handset from my etx 125 which has been sitting in the cupboard for around 20 years !  as far as i recall it works fine last time i used it and if you want to pm me your address i am also happy to send it on to you free.

Regards,

              Steve.

1 hour ago, A320Flyer said:

Very nice. Did you use the dedicated 0.8x reducer?

Hi A320Flyer, yes i was using the dedicated reducer  

2 hours total consisting of 180 second captures in Bortle 8 with a sharpstar 61 EDPH II 294 mc Pro and L-Extreme filter. Stacked in DSS, processed in Siril, Starnett++ and gimp.

Here is my humble effort of the Veil from last night.  57 x 90 seconds using a 61 EDPH II  294MC Pro and L-Extreme filter ( bortle 8 skies )  stacked in DSS then processed in Siril and Gimp.

26 x 180 seconds ( 1 hour 18 mins ) Stacked in DSS with master flat and dark, processed in Siril and Gimp.

Ioptron Gem45 -  Sharpstar 61 EDPH II @ F/4.5 with 294MC Pro and L-Extreme Filter.

Guiding with svbony 30mm F/4 and 178 Mono

Have you tried Gimp and Siril ( both free )   I use DSS to stack then Siril and finally gimp to process. The noise reduction and shadow functions in Gimp can reduce your stars, I had a little play with your images in Gimp ( hope you don't mind ) just to show you what is capable with a free program.

1:13:30 of data ( 49 x 90 seconds ) Still having slight  issues with coma and spacing of the corrector but a bit better than before. Using the GEM45, 200mm F/4, 294MC Pro with L-Extreme filter. Stacked in DSS with a master dark and flat, processed in Siril and Gimp. I will spend some time in the near future looking at some processing vids but winging it a bit for now  

7 hours ago, GoldTop57 said:

Nice image, and only 40 minutes of data. Did you do something to reduce the star field?

6 hours ago, AstroMuni said:

I suspect its the Optolong filter that causes this effect.

The L-Extreme certainly helps reduce star bloat but in gimp I played around with shadows-highlights and noise reduction. both helped eliminate the fainter stars. I was using the old Altair triband filter before but this filter blows it out of the water. I didn't even have to do background extraction on this stack  

First time using PH2 and dithering. Also the first time using the sw aplanatic cc and l-extreme. Spacing seems a little off as getting coma in the corners, using 55mm but i saw somewhere you need 53.66mm for 800mm fl. As a first light with this setup i am pretty pleased with the results.

Ioptron GEM 45 with TS photon 200mm F/4  ( Bortle 8 skies )

guiding with svbony 30mm f/4 scope and 178 mono

294MC Pro with Optolong L-extreme cooled to -10c

stack of 27 x 90 second frames with master dark and flat applied

Processed in Siril and Gimp.

Now to get my head around stacking, debayering raws, processing, etc   

Good to hear 👍  all your pics will have a green cast due to the bayer pattern ( 2 green to one blue and red ) you can use a program like siril ( free )  to remove the green cast or just balance the colour in post processing ( gimp, photoshop, etc. ) 

In sharpcap settings ( general ) have you ticked compress tiff files ? if so, best to untick until you find a software that can debayer compressed files. The image files will be bigger of course but at least you can debayer them  

Hi Jim,

           Yes it does, if you zoom in you can see the bayer pattern. The problem you might be having is that you are using compression and some programs ( pipp for instance ) cannot debayer compressed tiffs. I am sure someone with better knowledge on software can help  

Took a quick one at the end of an imaging session. 200mm F/4 newt and 294MC Pro. Best 25% of 5k frames , stacked in AS3, sharpened in Registax and processed in Gimp.

You could get one of these for the 294. 

https://www.firstlightoptics.com/zwo-accessories/zwo-anti-dew-heater-strip-for-asi-cooled-cameras.html

On 21/09/2021 at 06:53, Simon Pepper said:

Didn’t know WO were making one to be fair I will be sure to have a google and check it out! 

They were also working on a 91mm version but i am sure that one will be out of my price range  

On 21/09/2021 at 07:38, david_taurus83 said:

So, basically a Star 71 with helical focuser?

But, but.......   it's red  

Looks like the wait will soon be over for this scope, found this Taiwanese web page where it says it is for sale.

https://www.galuxe.com.tw/products/william-optics-redcat-71-apo-中紅貓天文望遠鏡

The discounted cost is around £1300 ( 49,500 new Taiwan dollar )

Compatible with full-frame and phase field range covered by APS-C cameras
Use APO grade FPL-53 optical lens
The design of the optical focus assist plate in the hood
With image field rotation system
Lightweight and easy to carry on expedition abroad
48mm filter screw can be built-in
Vixen/Arca-Swiss double pass specification dovetail version

RedCat 71 APO 

Optical form Refracting telescope
Effective caliber 71 mm
Coating Comprehensive multilayer coating
focal length 350 mm
Focus ratio (F) F4.9
Dovetail plate type Vixen Type and Arca-Swiss compatible
size 430mm long
The outer diameter of the hood 105mm
Weight 3.6 kg