Prolifics

my scope is F6.5 or F5.13 with the focal reducer.

I have the Pegusus power box so the dew heaters come on and off automatically when the due point gets near the temperature point. That would make a difference if the tube was getting slightly warmer by .5c would expand the tube?

Maybe having the due heaters on all the time would be better when its cold outside?

Regards David

Yes looked at 5 frames from each filter and nothing. Maybe your correct in temperature change. I will however in future refocus every filter to stop this issue.

David

48 minutes ago, vlaiv said:

Indeed. Flat darks are just darks for flats - same way you take darks for regular lights - you do the same for flats. Same exposure duration, same settings, everything the same as flats except you put scope cover on to block any light.

Great all understood!

I have had a look at all my frames and I do not see any out of focused doughnut stars. Maybe deepskystacker was the culprit? The HFD is between 0.50 and 1.37 for the whole starfield.

Here is a sample of a frame.

Regards David

Thanks Dave for your version it's very interesting seeing the subtle differences between versions. I may have another go myself later and see what I come up with

Regards David

Now that I done a bit of research. When I make my flat plans at the end of the session, I can use them again with the cap on the scope to take the dark/flats in a different directory as they will be named the same. Then just add them to deepsky stacker when stacking?

Cheers David

Hi Red Dwarf

Thank you for all the information. I have taken in everything you have said and that all makes perfects sense. I guess that means all my RGB filters must be Par focal and my LUM not matching with them?
Next time I will refocus for each filter that I use.

I will try next outing to re-focus and use the magnifier in apt on the stars to make sure there is no circles and make sure they are solid and round not fuzzy.

I am a bit confused with flat darks are these bias files? I will do a google search and research the flat/darks.

I am really happy you brought these points up. This will make me move further forward in the right direction. I am quite new to Astro photography this is my 5th image. Althought I have been into astronmy for 4 decades

So better focus and dark/flats next on the menu for me

You have done a great job on the image can hardly wait for the colour version

KIndest regards David

Hi Carole thank you for doing that I will take a look online for some tutorials. I am using cc 2018 PS.

I also bought some actions.

Kindest regards David

Thanks again Geoff for the heads up. there is no way I can afford Pixinsight at the moment and it's probably harder to use than PS

I will post a final image if I get one in here.

Thanks again David

Hi Geoff wow you don't messaround

Not too hot with Photshop I coverted the files to 16 bit and then applied deep space noise reduction.

Adjusted levels and curves bit by bit and then added a new layer and copied the RGB over and then added the LUm channel next to the background and adjusted to luminosity.

Thats about as far as I got.

Unfortunately I had some sort of image that I wasn't very happy with so quit photoshop.

I really need to go on a course or something for post processing.

Regards David

I took 

60s x 90 Lum
120s x 20 RG&B
50 Flats & 50 Darks

I have stacked the L R G and B data in deepsky stacker along with the darks and flats. But I don't seem to be getting much from the data via photoshop.

I am wondering if the data was any good? Bortle 5 sky, good seeing and guiding was excellent last night.

Files are located here https://www.dropbox.com/sh/rzkkbbbokj5fqei/AAAR-Jfsyvd3_6gDr3qGCyhwa?dl=0        if you fancy a play and can get anything with it.

Kindest regards in advance David

any ideas?

Hi I use eqascom (eqmod) and APTEverything was working fine last time I set up.

However when I slew to say Polaris it's not in APT live view window the RA is always 3.5 more on APT and EQmod then on the plate Solve coordinates. It will not synch either comes up with cannot syncg to coordinates exception occured.

Using Astap here is the screen with Polaris centered. Platesolv RA and Dec is correct but APT and EQmod althought the same are not.

Using Eq6 Pro and tried the hand controller and the direct Lynx astro cable and they are botht he same so ruels the cable out.

Screen for reference. Ignore the ghosting in middle this is actually a large antenna in the way

1 hour ago, alan4908 said:

I had a look at your data and used Pixinsight and Photoshop to process the result (below). As you can see you've captured quite a lot of detail. 

On the vignetting issue this seems to be mainly in the RGB data, your Lum data is much flatter. I eliminated both with the use of Pixinsight's DBE function - you can do a similar function in PS but you will require the use of the plug-in Gradient Xterminator. 

I also noticed that your lum data is very slightly misaligned with the RGB data, so I realigned this to get better stellar profiles.

Alan

 

Hi Alan thanks so much for doing that for me. It was the first time I used my scope with the focal reducer. I think stars are fairly round now. Use to be elongated near the edges. 

Like I said flats didn't come out right on the night was very tired from 4.5 hours of data  I tried taking the flats 3 weeks later and I think the issue with the fluffy bits is the reason. Not sure about the RGB data.

Not sure why deep sky stacker does not align properly its like a little bit off any settings you recommend to fix that. I use one of the LUM lights best score for the Reference frame as i shot either side of the Meridian and I don't have a rotator installed.

Kindest regards David

1 hour ago, wornish said:

Thanks for sharing the data which is very good.  This was processed in APP ( integration) and PI (background removal)then tweaked in PS.

 

I am certainly no expert but here is my attempt.

OMG thats amazing you can really see the detail even in the little galaxy in the north west of picture. So at least my stacking is fine

First thing I do in photshop is convert them all to 16 bit. LRGB

Then I level and curve adjust them all several times until I get better details.

Make a new layer and copy and paste the RGB data

Then I add the lum to the same layer.

Thats about as far as I got sometimes I play with saturation on the RGB too.

Kindest regards David

1 hour ago, wornish said:

 

 

 

4 hours ago, almcl said:

Take any flats?

They would help with the vignetting.

Yes 50 flats for each Filter
60 darks

Had to take the flats again 2 weeks after which has caused some problems.

Stacked files are here if you would like to play with them LRGB and see if the data is good.

https://www.dropbox.com/sh/rzkkbbbokj5fqei/AAAR-Jfsyvd3_6gDr3qGCyhwa?dl=0

Thanks in advance David

I think I have the data now just not the skills for post processing via Photoshop. My 4th image. I may have over streched the image a bit  If anyone else can do any better then I can post the data.

Intermittant clouds.

Data 90 x 1 min Lum
30 x 2 min Red
30 x 2 min Green
30 x 2 min Blue

TS 107 Triplet 700mm with 0.79 Focal Reducer F5.13

Regards David

I just tried indoors with 1 layer of white T-shirt and a led dimmly lit led panel on top of the T-shirt and it seems to have sorted itself.

It's managed 20,000 adu at 0.046 seconds exposure. Better than the 1m 36 seconds i got before  Not sure what was going on maybe APT feaked out or partially crahed after a 8 hour session.

Regards David

Thanks for the info I am going to set up my light panel and test it indoors. I am thinking its a bug with the latest version of APT. Use to be less than a second exposure now 1.5 minutes. Somethings wrong but it producing good images still.

I normally put a white t-shirt over the lens and a flat panel lit up by led on top. I have tried with and without the t-shirt but I will do some more tests.

Regards David

I am using a 107 Refractor Triplet 700cm F6.5 with a Zwo asi1600 Pro Camera and filterwheel.

I take my flats in APT and set it from 0.000032 seconds to 2 seconds and it works well at around 20k ADU. Exposure times very short sometimes less than a second.

However since I added my 0.79 Focal reducer bringing the scope to F5.13 and around 553cm Focal Length to reach 20k ADU exposure times are around 1 Minute 45 seconds each varying slightly dependant on filter.

I understand there is more light going t0 my scope which is probably has something to do with the mess up I am having with the ADU.

I worked out that a 12 bit ADC camera has the range of 0-4096 ADU so maybe trying 2,000 ish would work better?

KIndest regards David

I would presume they were geese. Did you get any close in shots of them? 😁

Its a beautiful image though I really like it. Stunning!

have you tried higher gains with narrowband like 200 to 300?

On 25/07/2019 at 06:16, alan potts said:

This is 93mins of 3 min subs on 3 nights, all the 3's.

Well done looks great. I love clusters especially when done in 3's. So I will award you 3 out of 3

Keep them coming!

On 25/07/2019 at 06:16, alan potts said:

 

 

 

 

I have been playing with numbers and will be doing 60 x 2 Min of Lum and 15 x 4 mim of RGB just about fit that in the darkness of August month.

What formulae do you use for Narrow band? I guess the exposure time is double of RGB but what about the Lum?

Another question my scope has a focal length of 700mm and i put this in APT so platesolving will work etc. When I get my x0.79 Flattener/Reducer do I put into my programs the new focal Length for example 700mm x 0.79 = 553mm ?

This is the link to small spacers to get my backfoucs perfect I just need 1mm + or -

https://www.365astronomy.com/baader-t-2-delrin-setting-rings-adjustment-spacer-rings-15-pieces.html

Kindest regards David

Haha -30 to keep everything constant   -1 and im already dead!

Do your cables freeze up rigid in -30 + that must be a problem. Maybe a small wooden hand made shed with sliding roof would stop that add +15c to the temp

I would make sure its all greased up well so really then you don't really need a cooler only to keep it constant. Bit like why you need a freezer up there in winter not to keep it cool but to stop everything from freezing.

I guess in midwinter you can image for 17 hours of the day?

Thanks for the link I will check that now. I am away Tuesday for a week so catch up with you then hopefully.

Cheers David