M81 Files

[Prolifics]

Hi I got my first ever data on M81 been trying to post process this data. Learning but not really getting anything. I just wanted to see if the data was any good.

Files are LRGB master .tiff files. I have stacked them with Flat, Darks and Bias.

https://www.dropbox.com/sh/skqoxrbe5huosg4/AAAdQ_UEP0XsX0S0b6oBPiiKa?dl=0

 

If you feel like playing to show me if my data is viable or not would be appreciated.

 

Regards David

 

 

[Xplode]

Firstly the luminace master is a RGB file, did you try to make a syntethic luminance file by stacking the RGB files?

Stars are large blobs so all your images are unfortunately out of focus
Looking at vignetting/donuts i can also say that your flats aren't fixing all problems perfectly.

[Adreneline]

1 hour ago, Prolifics said:

If you feel like playing to show me if my data is viable or not would be appreciated.

Well I managed to get something for you although I'm sure those with more expertise could achieve far better.

All the individual masters were rgb so I converted them to greyscale. I haven't used the Luminance master.

I took them into PixInsight, cropped the vignetting (not sure the flats are doing the best job for you) and then applied AutomaticBackgroundExtraction (ABE) twice, once as subtraction and then as division. I then created a luminance mask and applied some noise reduction. I then duplicated the image and to one I applied incremental/multiple HistogramTransformation (HT) and the other I applied an ArcSinhStretch. I took the resulting images into Photoshop and layered the HT image over the ArcSinh image as a lighten layer with about 40% opacity. Finally I applied a little bit of extra noise reduction.

You can definitely tell it is M81!

Maybe the focus could be a bit tighter and there are a few artifacts on the masters I don't understand (especially the red for some reason) but hey! - you got a pretty good first image hiding in amongst all that data.

HTH

Adrian

P.S. May I ask how you are taking your flats?

Edited May 18, 2019 by Adreneline

[Prolifics]

2 hours ago, Adreneline said:

Well I managed to get something for you although I'm sure those with more expertise could achieve far better.

All the individual masters were rgb so I converted them to greyscale. I haven't used the Luminance master.

I took them into PixInsight, cropped the vignetting (not sure the flats are doing the best job for you) and then applied AutomaticBackgroundExtraction (ABE) twice, once as subtraction and then as division. I then created a luminance mask and applied some noise reduction. I then duplicated the image and to one I applied incremental/multiple HistogramTransformation (HT) and the other I applied an ArcSinhStretch. I took the resulting images into Photoshop and layered the HT image over the ArcSinh image as a lighten layer with about 40% opacity. Finally I applied a little bit of extra noise reduction.

You can definitely tell it is M81!

Maybe the focus could be a bit tighter and there are a few artifacts on the masters I don't understand (especially the red for some reason) but hey! - you got a pretty good first image hiding in amongst all that data.

HTH

Adrian

P.S. May I ask how you are taking your flats?

Hi Adrian

 

Thank you for taking the time to do that. I focused with a Bahtonov Mask checked it in APT HDR was around 1.6.  I took my flats by placing a white t-shirt over the lens in a near dusk scenario. I used APT to help me set up the flats with a 16000 ADU. 20 flats, 20 darks and 20 bias. There was approx 17 frames of each at 3m exposures LRGB totaling around 3h 45 minutes in total.

 

I did have some problems in PHD2 at some point. The graph went AWOL!  Guiding was averaging 0.72 in general. I inspected each frame. Not sure what to do about the RGB stacked images I just saved each stacked colour as .tiff. Should I be saving them as greyscale? Loaded up each colour seperately in DSS and flats, dark and  bias. Stacked good pictures as saved. Used options from many Youtube tutorials.

 

Also to the left of centre mainly looks like my cat got her paws on the canvas  Not sure what caused this maybe Dew drips?

 

Regards David

Edited May 18, 2019 by Prolifics

[Adreneline]

Hi David,

18 minutes ago, Prolifics said:

I focused with a Bahtonov Mask checked it in APT HDR was around 1.6.

I've used a BM with and without success. I've recently started using SharpCap (£10 per year) to help me focus with a preference for FWHM measurements but success depends on so many things, including the 'seeing'.

21 minutes ago, Prolifics said:

I took my flats by placing a white t-shirt over the lens in a near dusk scenario.

I do pretty much the same but I have had more success using a uniform light source; I use my iPad running a lightbox type app and get very consistent results; the flats also work!

22 minutes ago, Prolifics said:

Guiding was averaging 0.72 in general.

Well done you! I'd be happy to have that average over an imaging session.

23 minutes ago, Prolifics said:

I just saved each stacked colour as .tiff.

tiff is just fine but I wonder whether it is DSS that decided to save as rgb rather than greyscale. I presume you have checked it is expecting to process mono images - it's in one of the Settings menus somewhere - can't exactly remember where though.

As for the artefacts I'm really not sure what to say - it doesn't look like dew to me. It may be the flats just not doing their job properly.

Another thing I would say is that the advice seems to be not to use Bias with a ASI1600 Pro. Rightly or wrongly (but it seems to work for me) I've started using flats + dark + dark-flats (instead of bias). If I'm doing something very wrong then hopefully someone will pop up and put me straight! Dark-flats are exposures taken with exactly the same exposure times as the corresponding flats but with the lens cap on - hence dark! You can use them in DSS.

I would have another bash at taking your flats. I know dust bunnies may have moved but it might correct the vignetting problems you are experiencing. People use a variety of white light panels; I tried using one of the Huion panels but found it gave me severe 'banding' when used with both my dslr and ccd's so I gave up.

HTH

Adrian

[Prolifics]

3 hours ago, Xplode said:

Firstly the luminace master is a RGB file, did you try to make a syntethic luminance file by stacking the RGB files?

Stars are large blobs so all your images are unfortunately out of focus
Looking at vignetting/donuts i can also say that your flats aren't fixing all problems perfectly.

Thanks for the constuctive criticism. 

For the Lum i stacked dark flat and bias with the lum only data.

I used HDR to 1.6 on SGP and APT. I will need a routine to improve my focus

Flats do have a problem I need to get a better light source.

 

[Prolifics]

7 minutes ago, Adreneline said:

Hi David,

I've used a BM with and without success. I've recently started using SharpCap (£10 per year) to help me focus with a preference for FWHM measurements but success depends on so many things, including the 'seeing'.

I do pretty much the same but I have had more success using a uniform light source; I use my iPad running a lightbox type app and get very consistent results; the flats also work!

Well done you! I'd be happy to have that average over an imaging session.

tiff is just fine but I wonder whether it is DSS that decided to save as rgb rather than greyscale. I presume you have checked it is expecting to process mono images - it's in one of the Settings menus somewhere - can't exactly remember where though.

As for the artefacts I'm really not sure what to say - it doesn't look like dew to me. It may be the flats just not doing their job properly.

Another thing I would say is that the advice seems to be not to use Bias with a ASI1600 Pro. Rightly or wrongly (but it seems to work for me) I've started using flats + dark + dark-flats (instead of bias). If I'm doing something very wrong then hopefully someone will pop up and put me straight! Dark-flats are exposures taken with exactly the same exposure times as the corresponding flats but with the lens cap on - hence dark! You can use them in DSS.

I would have another bash at taking your flats. I know dust bunnies may have moved but it might correct the vignetting problems you are experiencing. People use a variety of white light panels; I tried using one of the Huion panels but found it gave me severe 'banding' when used with both my dslr and ccd's so I gave up.

HTH

Adrian

I have Sharpcap as it comes free with my Altair GPcam2 aor130 but I first started using SGP for focus with the mask by right clicking picture and using the HDR option on the menu. Not sure how to do that with Sharpcap will take a look later. But if i change camera it will de-license itself as its only a full version with the Guidecam above selected. I use Sharpcap for my Polar Alignment.

I will investigate in a better light source for my flats some sort of evenly lit panel that has different brightness options and try the flats again. I will stop the bias frames from now on. 

I will also investigate options in DSS so they don't save as RGB and ssave as Greyscale.

After that lot is sorted I may see some of the problems go away

 

 

 

 

[Adreneline]

6 minutes ago, Prolifics said:

I used HDR to 1.6 on SGP

From purely personal experience I have found SGP hdr focussing not to yield good or consistent results. I have wasted so much time trying to get autofocus to work that I now focus manually, albeit with a stepper motor focus unit - I go and stand outside and use SharpCap on a laptop - five minutes (if that) and I'm done.

As for SharpCap I've decided £10 year is money well spent; it is constantly being updated and improved. I use both the FWHM Measurement and Bahtinov Mask options and find I get very good results.

Solving problems is all part of the fun! Not sure you ever reach the point where you've solved 'em all though!

Good luck.

Adrian

 

[Prolifics]

On 18/05/2019 at 13:27, Adreneline said:

From purely personal experience I have found SGP hdr focussing not to yield good or consistent results. I have wasted so much time trying to get autofocus to work that I now focus manually, albeit with a stepper motor focus unit - I go and stand outside and use SharpCap on a laptop - five minutes (if that) and I'm done.

As for SharpCap I've decided £10 year is money well spent; it is constantly being updated and improved. I use both the FWHM Measurement and Bahtinov Mask options and find I get very good results.

Solving problems is all part of the fun! Not sure you ever reach the point where you've solved 'em all though!

Good luck.

Adrian

 

Hi Adrian 

 

Out with the scope used Sharpcap and used the Bahtanov mask and focused exactly the middle spike to the centre. Then went to  FWHM Measurement mode in Sharpcap showed as 5.6 I used the fine focuser and got the bars down to low yellow average 3.3. It won't go any lower than that. 3.3 Obviously an improvement over 5.6 whcih is where my setting were on my first upload.

 

I also found huge movement in my EQ6 Pro mount on the dovetail head of over 6mm  Tightened the 3 tap screws and re-aligned for home park position.

 

So tonight I aim to do some 2 minute exposures. I will let you know how they turn out if they look OK i'll upload them so you can take a look. I think I am heading in the right direction  Thank you for all your valuable help!

 

Kindest regards David

[Adreneline]

27 minutes ago, Prolifics said:

So tonight I aim to do some 2 minute exposures.

Good luck David! Hope you get some good results tonight; not easy on these short nights when Mr Moon is up and about but it's still a good opportunity to sort out a few niggling issues and problems.

Next time I get my gear out I will be sure to screenshot the focussing results I get with SharpCap for comparison.

Looking forward to seeing the results of tonights endeavours!

Adrian

[Prolifics]

16 hours ago, Adreneline said:

Good luck David! Hope you get some good results tonight; not easy on these short nights when Mr Moon is up and about but it's still a good opportunity to sort out a few niggling issues and problems.

Next time I get my gear out I will be sure to screenshot the focussing results I get with SharpCap for comparison.

Looking forward to seeing the results of tonights endeavours!

Adrian

Hi Adrian

 

Your right about moon and short time to aquire an image. I decided to take 20 x 1 minute exposures in LRGB I stacked them in DSS without dark or flats. I wanted to eliminate any problems.

Link not M81  https://www.dropbox.com/sh/skqoxrbe5huosg4/AAAdQ_UEP0XsX0S0b6oBPiiKa?dl=0

Firstly I wanted to see if the focus was better and if I eliminated those red problems. Please give me your views if you have any time on your hands to download the new data of a new object. I noticed I have no claw marks now (probably caused by bad flats). But I still see what looks like coin size circles around SW of centre. Are these from the filter wheel or dirt? Scope is brand new nearly.

When I load my masters into PS they are RGB/32 bit. I saved them in DSS as 16 bit not sure either why they are not greyscale when I load them in?

 

Look forward to your honest opinions

 

Kindest regards Davd

 

 

 

Edited May 21, 2019 by Prolifics

[Adreneline]

2 hours ago, Prolifics said:

Please give me your views if you have any time on your hands

Will certainly take a look and get back to you later/tomorrow.

 

[Adreneline]

Hi David,

Well I've had a go.

On the positive side this is a really well framed image of M101. I would say you have definitely improved the focus issues you were experiencing. Don't forget that achievable absolute FWHM is dependent on so many things and trying to achieve some magic low value on any given night is pointless. In my view you need to achieve the lowest value you can for a given filter - they will all vary. With my ED80DS I find that blue never focusses as well as red, green or luminance. Many of my rgb images suffer from blue bloat around the stars.

On the negative side the flats are clearly not doing what they should be doing as all the masters exhibit severe vignetting and evidence of dust bunnies; I would suggest the latter are on the filters as they move from filter to filter.

Having said that I have done my best (I'm sure others could do better) to reduce the effect of vignetting and dust bunnies as much as possible, probably at the expense of some of the outer arms of M101.

I've processed pretty much as before but this time I also used the Luminance image as a 'Lighten' layer in Photoshop at about 45% opacity.

Can you post one of the master flats - anyone - so I can have a look please.

HTH

Adrian

[Prolifics]

8 minutes ago, Adreneline said:

Hi David,

Well I've had a go.

On the positive side this is a really well framed image of M101. I would say you have definitely improved the focus issues you were experiencing. Don't forget that achievable absolute FWHM is dependent on so many things and trying to achieve some magic low value on any given night is pointless. In my view you need to achieve the lowest value you can for a given filter - they will all vary. With my ED80DS I find that blue never focusses as well as red, green or luminance. Many of my rgb images suffer from blue bloat around the stars.

On the negative side the flats are clearly not doing what they should be doing as all the masters exhibit severe vignetting and evidence of dust bunnies; I would suggest the latter are on the filters as they move from filter to filter.

Having said that I have done my best (I'm sure others could do better) to reduce the effect of vignetting and dust bunnies as much as possible, probably at the expense of some of the outer arms of M101.

I've processed pretty much as before but this time I also used the Luminance image as a 'Lighten' layer in Photoshop at about 45% opacity.

Can you post one of the master flats - anyone - so I can have a look please.

HTH

Adrian

Hi Adrian 

 

Thanks again for all your help. As I stated above there is no flats or darks in this image. I did not want to complicate matters and wanted to try and fix focus issues etc. Would you suggest next to use some flats and darks taken on the same evening as I take some exposures? I also am waiting on my light panel to arrive. So seeing there are no darks or flats in these stacked images I think they have turned out ok ish  This is still my 2nd ever object I have imaged. Next to the flats and darks. 

My theory on Darks is to take:

same length of Exposure as lights
Same Gain and offset as Lights
Complete darkness and temperature as of lights taken.

Flats will need experimenting with via APT Flats maker and a suitable Light source.

 

Also Using FWHM in Sharpcap making the square reitcle smaller over a star also brings down the Focus number

 

Also PHD2 guiding on my gear modded eq6 pro was 0.51 over 1.5 hours. There was a time that for 35 minutes no corrections to the graphs were ever made. I though that this was an error but it was guiding at 0.23 (total error) then

I run Phd2 guiding right out of the box as to say and don't even bother with the guiding assistant.

 

 

Kindest regards David

 

 

 

Edited May 21, 2019 by Prolifics

[Adreneline]

40 minutes ago, Prolifics said:

As I stated above there is no flats or darks in this image.

Sorry about that - it's getting late and I wasn't concentrating on what you wrote regarding the flats.

You can take darks at any convenient time as long as they are at the same temperature, exposure, gain and offset. Complete darkness is essential. People often use the sensor cover supplied with the camera; some advocate wrapping it in tin-foil. The considered view is poor darks introduce more problems than they solve. I guess you can say the same for any calibration frame!

I usually take my flats the following morning - I'm usually too tired to do it at the end of an imaging session. I can't see it being an issue providing you don't disturb the imaging train at all. If dust bunnies move they can often be reduced during processing. The flats will really help with the vignetting. You should take the dark-flats at the same time but with the lens cap on.

It's all going in the right direction and looking good!

Apologies again for not registering the lack of flats and darks.

Adrian

Edited May 21, 2019 by Adreneline

[Prolifics]

1 minute ago, Adreneline said:

Sorry about that - it's getting late and I wasn't concentrating on what you wrote regarding the flats.

You can take darks at any convenient time as long as they are at the same temperature, exposure, gain and offset.

I usually take my flats the following morning - I'm usually too tired to do it at the end of an imaging session. I can't see it being an issue providing you don't disturb the imaging train at all. If dust bunnies move they can often be reduced during processing. The flats will really help with the vignetting.

It's all going in the right direction and looking good!

Apologies again for not registering the lack of flats and darks.

Adrian

Hi again Adrian

 

No problem I do that a lot myself  I think I got the PHD2 tracking great and the focus acceptable. Just need a clear night and try with flats and darks. A never ending learning process thats why I am enjoying it so much

I usually stay up until i go unconscious  Then I realise I need to bring the scope and mount in as well as all the wires. I need to organize myself and finish 45 minutes earlier so I can take the flats just before I fall to the ground

Have a good sleep.

[Prolifics]

My flat panel should arrive tomorrow. In APT the ADU is set as default at 20,000 should I leave it there or change it. Some people have mentioned 12,000 is better? Or use a histogram and do it that way?

I would like a good start to my flats probably take 40 per filter.

 

Regards David

 

[Adreneline]

On 22/05/2019 at 13:08, Prolifics said:

In APT the ADU is set as default at 20,000 should I leave it there or change it. Some people have mentioned 12,000 is better? Or use a histogram and do it that way?

Well I’m not sure. In SGP I go for 30,000 - 32,000 or thereabouts. That’s always worked for me. 

Have a go at a range of settings and see what works best. 

😊

[Prolifics]

Weather been aweful no clear skies for last 8 days and not looking good for bnext 5 days either :(

I received my light panel so wikll check it out as soon as I can.

 

 

[Adreneline]

Good luck with the light panel - at least it should provide consistent and repeatable results.

[Prolifics]

On 05/06/2019 at 20:40, Adreneline said:

Good luck with the light panel - at least it should provide consistent and repeatable results.

Thanks not been a clear night since I last spoke to you. Looking better for next week. Its because I bought a light panel :)

 

[Prolifics]

Another major fix I have just made which I would have not picked up on if I wasn't scouring the forums. My EFW zwo wheel was on the wrong way. Which means the gap between the camera lens and the filter was 8.5mm instead of 2.4mm approx. Plus it also meant the filters were on the wrong way. I reversed it all and the camera is on the correct side of the filter wheel now and the screw threads on the filters are facing the camera.

Which accounts for those big black reflection filterwheel size circles on my images  Should also reduce vigneting sigificantly!

 I just purchased and installed the EAF ZWO Auto focuser and is working like a dream. Can't wait to get back out hopefully this weekend for another try. Will post end results. 

 

Regards David

Edited June 26, 2019 by Prolifics

[Prolifics]

Managed to get out last night. Spent alot of time getting the autofocuser working as I wanted it. I ended up with only a couple of hours so I tried M13. With the filter wheel the right way around

I have no photshop skills as you can see. Took me about 10 minutes to get something that qualifies as identifiable. Flats seem to have worked a lot better this time. Be pleased to have some input please as this is a minefield in learning which I love.

Guiding averaged 0.85 in PHD2
HWFM 1.37 and HDR 0.50 using ZWO EAF 

30 x 1 min Luminace
15 x 1 Minute Red
15 x 1 Minute Green
15 x 1 Minute Blue

20 Darks
20 Flats @25000 ADU

 

PS. I have some slightly oval stars to the edges are these caused by not having a Flatener/Focul reducer? I should have cropped the picture but left it as is.

 

 

 

Edited July 1, 2019 by Prolifics