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JGM1971

The "No EQ" DSO Challenge!

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2 hours ago, Minhlead said:

Looks like the denoise algorithm of Astra is somewhat better than lightroom but you still lose detail when do the denoising in post so I'm looking to optimize my stacking workflow. But thanks for the suggestion :D

Bear in mind that I did that on a screen grab of a jpg, you can do it on your 16 or 32 bit uncompressed original data.

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On 10/02/2019 at 00:39, Stub Mandrel said:

Bear in mind that I did that on a screen grab of a jpg, you can do it on your 16 or 32 bit uncompressed original data.

wow, really? Thanks! I think I'll give it a try :D

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9 hours ago, Minhlead said:

wow, really? Thanks! I think I'll give it a try :D

Just to be sure, I mean using it on after stacking your data but you need to experiment with the best point in your processing workflow to use it.

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Last year I started experimenting with using a 200mm M42 lens piggybacked (well actually side-backed) on to my Nexstar 4SE to give a larger field of view through the GPCAM IMX224. I'm still early on the curve, but finally feel confident enough to share, especially as last night was suddenly a clear sky, and very welcome it was too.

So please see M31 (59x16s subs, 14x8s darks) and NGC2244 Rosette Nebula (166x15s subs, 14x8s darks) taken last night. Oh yes, and just to confirm the Nexstar was running Alt-Az! All processed using DSS followed by GIMP for some stretching. Frankly I think my GIMP work could use some more practice!

It's only when you give it a go that you realise just how much hard work goes in to even getting a half-decent image... The pictures you all take are amazing!

 

Well, clear skies to all.

Nexstar4SE.jpg

m31 dss 16sec darks v4medianRGB_stretched.png

ngc2244 dss 16sec darksMax v2medianRGB_stretched.png

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Nice start. I've got the same 200, just wondering what aperture you used, is it full open (f/4) ?

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Good question! For M31 it was around f/4.5, but I tried stopping it down a little more on NGC2244, around f/5.6. Not sure it made a lot of difference to sharpness.

While I nothing about camera lenses it seems pretty sharp, even wide open at f/4. And my thanks to @Bobby1970 who sold it to me a while back!

Viewing this page now on my iPhone the colours are all a bit mangled (or absent) compared to on my laptop last night... so... if you’re looking at my pictures and wondering what’s going on then close your eyes and imagine Hubble took it 😁

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On 23/10/2014 at 10:22, Martin Meredith said:

Great idea. Everything I do is in alt-az, mainly in short exposures for "near-live" observing (none of these are for hanging in your gallery). All taken with the SX Lodestar-C guide camera using SW Quattro CF 8" f/4, no filters unless mentioned nor coma correctors. All are saved screenshots from Paul81's wonderful free LodestarLive application with no further manipulation. I mainly post on the video forum but these are as yet unseen shots.

BTW alt-az induced field rotation is not much of an issue with live stacking + shortish subs. I mainly limit myself to 60s with my 80mm f/6 refractor and 30s with the Quattro.

NGC 6946 Fireworks galaxy 1 x 30s

post-11492-0-58630900-1414080558.png

M1 Crab (rather low at 23 deg at the time) 4 x 30s

post-11492-0-46143700-1414080597.png

M101 4 x 30s

post-11492-0-62855100-1414080636.png

B33 Horsehead + NGC2023 (stupidly low at 16 deg and with out-of-date darks but irresistible and a proof that I'm mainly an observer and not an imager :smiley: ) 4 x 30s

post-11492-0-27319800-1414080513.png

Part of the Veil with O-III filter 3 x 30s

post-11492-0-61697100-1414080783.png

NGC7635 Bubble 4 x 30s

post-11492-0-35307000-1414080721.png

M27 1 x 30s

post-11492-0-24139300-1414081105.png

Cheers

Martin

Are you still active on here Martin? I see this is from a good fee years back but I've often wondered about the quattro  on an  alt/alz mount. Wouldn't  mind picking your brains if you're  still here.

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I'm still here! I've been a little busy lately (mainly coding up a new tool for EAA which will be ready soon). Anyway, fire away! The Quattro + alt/az is still my main scope.

Martin

 

 

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Thanks  , I was just wondering  mainly about clearance.  The mount I have is the evolution  mount.  I can only get about 63° with the sct when the camera is on ect, which is good enough for me. I'm guessing  the Newt is quite a lot heavier  to the rear which would allow me to push it forward quite a bit without it being too much front heavy? I've searched high and low online for a picture of my mount with a newt on and cant find one. 

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Hi

I'm not sure about the Evolution mount. Mine is the AzEQ6 mount and I don't have a problem with clearance at any point as you can see. While the scope is bottom heavy, by the time you take the focuser, camera and filter wheel (and dew shield) into account, it is surprisingly evenly-balanced anyway.

The Quattro is quite short too being f4. 

 

1508297299_ScreenShot2019-02-13at21_50_23.png.5df50142c8103d6baa4a303260d05792.png

 

I can't resist sending this one to show just how small the 8" Quattro is (and not a matter of perspective). 😉 But it does indicate where the balance point is.

1110734055_ScreenShot2019-02-13at21_56_27.png.e836c66d49b7fab454f20a301410a40a.png

 

Yes, the EAA software will be available to anyone who wants it.

Martin

 

 

 

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Bloody hell that dob. Thanks for the info. I'll maybe make a mock one up out of card and see what the clearance might be.

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The rear clearance looks worse than an SCT with image train for the evo mount. I think pushing the newt too far forward could cause issues in the wind.

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On 11/02/2019 at 22:42, Grogfish said:

Last year I started experimenting with using a 200mm M42 lens piggybacked (well actually side-backed) on to my Nexstar 4SE to give a larger field of view through the GPCAM IMX224. I'm still early on the curve, but finally feel confident enough to share, especially as last night was suddenly a clear sky, and very welcome it was too.

So please see M31 (59x16s subs, 14x8s darks) and NGC2244 Rosette Nebula (166x15s subs, 14x8s darks) taken last night. Oh yes, and just to confirm the Nexstar was running Alt-Az! All processed using DSS followed by GIMP for some stretching. Frankly I think my GIMP work could use some more practice!

It's only when you give it a go that you realise just how much hard work goes in to even getting a half-decent image... The pictures you all take are amazing!

 

Well, clear skies to all.

Nexstar4SE.jpg

m31 dss 16sec darks v4medianRGB_stretched.png

ngc2244 dss 16sec darksMax v2medianRGB_stretched.png

How did you connect the camera to the lens, and then the whole assembly to the scope? (Sorry to go OT, I used to attach my DSLR using rings to my 127slt but it's too heavy for the mount.

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I have the same sort of mount head on the virtuoso. I have a dove bar I fitted a camera shoe clamp to, the wooden block stops any twist.

Perhaps either of these would work in the Celestron mount head.

IMG_20170115_205552.JPG

And the skywatcher L bracket gives the other orientation.

IMG_20161231_100154.JPG

Edited by happy-kat
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30 minutes ago, jimbo747 said:

How did you connect the camera to the lens, and then the whole assembly to the scope? (Sorry to go OT, I used to attach my DSLR using rings to my 127slt but it's too heavy for the mount.

Sooo... I have an M42 to C mount adapter - cost around £18 on eBay. I also have the Altair GPCAM bracket that holds the camera and provides various screw mount points. That I attach to the Nexstar 4 using the Nexstar 5/6/7 piggyback camera adapter. And because it’s designed for a SCT, it doesn’t quite fit.. however mounting the piggyback holder reverse does seem to fit ok (and not block the eyepiece holder), but it means the holder (and thus the camera) stick out to the side of the Nexstar, rather than being on top.

All a little Heath Robinson... but.. kinda starting to get some results!

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On 12/02/2019 at 19:49, rotatux said:

Nice start. I've got the same 200, just wondering what aperture you used, is it full open (f/4) ?

What aperture do you tend to use with the 200mm? Do you run full open, or shut it down a bit? 

I’ve also got a f/2.8 135mm cosinon lens, but I’ve not had a chance to try it out much- and when I have I wasn’t particularly impressed- it appeared very soft at f2.8

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My copy of the 200 (same "bokeh monster" variant as yours) is very soft at F/4, I must close nearly at F/5.6 to get decently shaped stars (esp. on borders and corners). This is why I ended getting another 200 (Olympus OM) which is fine wide open at F/4 (though it suffers another aberration).

About 135mm I've got many, 2 M42/Pentacon F/2.8 (long and short) that are both good at F/4 (the long variant is a bit better), and 2 F/3.5 from Minolta and Olympus which I barely tested but need to be closed at F/5.6 (Minolta much better). Having to close is normal I think, the shortest the focal the bigger aberrations need to be corrected by closing; Only long focals would be kept wide open, at 200/4 you can find many good ones (don't know at 200/3.5), at 135 I didn't encounter any yet (but maybe some F/2.8 from Minolta, Takumar or Pentax) -- though if you have budget there's the Samyang 135/2 which is a wonder from what I have read everywhere.

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39 minutes ago, rotatux said:

My copy of the 200 (same "bokeh monster" variant as yours) is very soft at F/4, I must close nearly at F/5.6 to get decently shaped stars (esp. on borders and corners). This is why I ended getting another 200 (Olympus OM) which is fine wide open at F/4 (though it suffers another aberration).

About 135mm I've got many, 2 M42/Pentacon F/2.8 (long and short) that are both good at F/4 (the long variant is a bit better), and 2 F/3.5 from Minolta and Olympus which I barely tested but need to be closed at F/5.6 (Minolta much better). Having to close is normal I think, the shortest the focal the bigger aberrations need to be corrected by closing; Only long focals would be kept wide open, at 200/4 you can find many good ones (don't know at 200/3.5), at 135 I didn't encounter any yet (but maybe some F/2.8 from Minolta, Takumar or Pentax) -- though if you have budget there's the Samyang 135/2 which is a wonder from what I have read everywhere.

Phew! That's a collection.

Have you tried a Zeiss? - it was they that invented the Sonnar configuration. This is the  135 f 3.5 wide open:

987338051_Cygnus2.thumb.png.0db3924ba78396f92204cf4f3069e9f0.png

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Thanks Rotatux. Sounds like I need to be braver at stopping down the 135mm. The Samyang looks fantastic, but out of my price range sadly.

Regards star bloat I’ve not satisfied myself how much it’s due to poor focus, aberration, stacking technique, or bloom from a pixel well overflowing on the cmos (is that the right terminology?!).  Not really thought about it like this before, but I suppose I need to work out how much each of those is contributing to star bloat to push my imaging on a level...  that’s given me some homework for the next month!

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23 hours ago, Stub Mandrel said:

Have you tried a Zeiss? - it was they that invented the Sonnar configuration. This is the  135 f 3.5 wide open:

It's a nice image with regular stars on the whole field, but I can see the diffraction pattern of a closed diaphragm on bright stars... so are you sure it was wide open ? Anyway my collection only grew from trying several lenses to find an astro-correct one, and I will sell most of it ASAP but no Zeiss yet :)

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2 hours ago, rotatux said:

but I can see the diffraction pattern of a closed diaphragm on bright stars... so are you sure it was wide open

Good point! Perhaps it wasn't?

I have used it wide open.

It does suffer a bit of CA with blue stars getting small haloes, but easy to process out.

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Quote

 

Hi everyone! 

Congratulations on a very informative and inspiring topic. 

I live in Bucharest and my pictures are made under a high light polluted skies from my balcony. My setup is: Meade LT-8 ACF, Fujifilm X-A1 camera, Optolong L-Pro filter 2" and Antares f/6.3 focal reducer. I am at the beginning of the astrophotography road. I do not like equatorial mounts, for me they are bulkier and not as easy to setup. So, here are my attempts (DSS and Startools) :

M81 & M82, 60x25sec, 30 dark, 30 bias, 30 flats

247722446_M81M82.thumb.jpg.822a4c35ca16d1c814297766c892654f.jpg

M108, 30x25sec, 30 dark, 30 bias, 30 flats

M108.thumb.jpg.f4f95b06d6269f487f6c9333dc8edcee.jpg

Thank you, 

Cezar

Edited by antaeus
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Welcome to the thread, great images there with good colour showing too.

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