Rosette Nebula- difficulty seeing in live view and in post processing, is it there??

[el_hop87]

Hi, I am beginning out in astrophotography and so far have managed to get relatively OK pictures of Milkyway nightscapes, the Andromeda Galaxy and the Great Orion Nebula. I would now like to move on to other Nebula/ galaxies but am having difficulty - I attempted the Rosette Nebula from my back garden (bortle 6) using the following equipment: unmodded Nikon D5200, SW 72ED, SW AZ GTI in eq mode and the IDAS P2 light pollution filter. 

I could not see the Rosette Nebula on my live view screen whilst shooting but was quite sure the camera/scope was in the right position because the star formations I could see look very similar to the ones around/in the Rosette Nebula, and so I presumed it would appear during post processing - unfortunately this isn't the case and I can't seem to bring it out! 

I have attached my stacked image TIFF file (even that looks strange!) of 209 frames, 22 secs each at ISO 1000, total exposure time is 1 hr 11 mins. I have also attached a single frame to see if any one thinks there was a problem at that point (as you can see the Rosette Nebula is undetectable in both)....

I would very much appreciate any help anyone can give please! - I love this hobby, it is a sharp learning curve though and I seem to have hit a barrier that am finding it hard to move through!

Many thanks in advance. 

Elly

Autosave.tif DSC_0507.NEF

[Cornelius Varley]

Hello and welcome to SGL. Can you upload the tif file as a jpg or png so that it can be displayed without the need to download it?

[el_hop87]

Sure, here it is in JPEG. 

Thank you 

[carastro]

I can see Rosette is there by the star formation in the centre - the diagonally placed group of 6 stars.  I will just have a go at processing it and report back.  I think 22secs might not be long enough though.

Carole   

[el_hop87]

Hi Carole, 

Great news that you can see it

Each frame was 22 seconds, but the JPEG and TIFF file contain all the images stacked, total time is 1 hour 11 mins. 

Thank you so much for looking at this! 

[almcl]

Agree with Carole, 22 sec exposures with an unmodded camera on a target like the Rosette is going to be tricky.

The good news is that you have got it, image below is just cropped and wiped and then given a gentle stretch:

[pete_81]

Hi Elly, keen to see how this develops... Going to stab in the dark and guess your exposure time should be much longer. Image looks right location, but gut feeling is too short for a magnitude 9 object. I'm trying to build a list of DSOs with camera settings for starting things (https://stargazerslounge.com/topic/373623-dso-dslr-exposure-values) with aiming help for those new to DSO AP and keen to hear what camera settings are used throughout!

 

[pete_81]

Aha, and the refreshed page shows other folks suggesting same . Have another go and let us know!
PS, hope it's OK that I've taken your settings and listed them on my 'database' listing, link in the above comment.

Edited March 12, 2021 by pete_81

[el_hop87]

Almcl - thank you! very positive at least to know that it is in the right position and there somewhere! Is the image you attached one that you've taken? Thank you for your advice! 

Pete_81 - thank you for this. I would love to take longer exposures but seem to get star trails around 22seconds using the same equipment - I know guiding is the next step but not in the position to invest in this yet (plus I feel I need to consolidate the basics!) 

Sounds like you are building a very useful tool to help there, great idea and am sure many will appreciate that (myself included!). 

 

[almcl]

1 minute ago, el_hop87 said:

 Is the image you attached one that you've taken? Thank you for your advice! 

No, no!  It's your image just very lightly processed in StarTools - you've done much better than you thought!

[david_taurus83]

1 minute ago, el_hop87 said:

Almcl - thank you! very positive at least to know that it is in the right position and there somewhere! Is the image you attached one that you've taken? Thank you for your advice! 

Pete_81 - thank you for this. I would love to take longer exposures but seem to get star trails around 22seconds using the same equipment - I know guiding is the next step but not in the position to invest in this yet (plus I feel I need to consolidate the basics!) 

Sounds like you are building a very useful tool to help there, great idea and am sure many will appreciate that (myself included!). 

 

That looks like your picture!

How have you polar aligned? You should be able to do better than 22s.

[alacant]

27 minutes ago, el_hop87 said:

(even that looks strange

Hi

Looks good to me. OK, the image drifted over the course of the session and there seems to be quite strong light pollution from below but cropping and developing brings some nice detail. 

Cheers and HTH.

[el_hop87]

David_taurus83 - is it my picture?? - if so I would be delighted! - and need to learn a lot more about post processing skills because I am not sure how this would have been achieved. Currently using DSS, Photoshop and Lightroom, but am clearly missing something if this is my pic...

I am polar aligned using a polarscope that I have attached to the mount (AZ GTI) not ideal as the mount does not have an inbuilt scope. The aim is eventually to get Stellarmate/ AsiAir and use that to platesolve/ polar align. 

[el_hop87]

Alacant- Oh wow, is that my TIFF file?? - its incredible that you've managed to do that with it! - thank you so much!! Are you able to tell me what programs and methods you used please? 

Thank you! 

[alacant]

 

4 minutes ago, el_hop87 said:

is that my TIFF...

Yes.

I used StarTools.

Cheers

Edited March 12, 2021 by alacant

[el_hop87]

Alacant, thanks so much! Would be really interest to know how you achieved this in post processing if at all possible to share please?

[pete_81]

Stats now on my post too

So you mention guiding - this is to reduce drift etc, but what about simple tracking? Tracking should give at least minimal star-trails for a little longer. Also, the D5200 should be able to cope with higher ISO, don't hesitate to push it up a bit more. My attempt on Orion nebula on my post was more to play with 1st attempt and also more guiding. I'm new to guiding too and the learning curve with it. So thinking to master (or get better!) at that, then go for attempts with DSOs using just the camera lenses I have before mounting to faster and longer optics.

Look at photoshop 'levels' & 'curves' adjustments on the tiff, and spend more time on PS than lightroom, the amount of 'stretching' to be done I don't think one can do in LR, at least not as quickly as PS.

But yeah, a good start and nice image! Post is as much a steep learning curve as the setups! @almcl@alacant, what edits did you apply to the tiff? ie - layers, levels, black5 white20, new layer, repeat, etc? This would be really helpful!

Good luck and keep us posted.

[carastro]

This is my result.   Processed in Photoshop, mostly levels and curves and gradient exterminator.  Needed a lot of stretching due to the data being faint.  You won't see this target on live view with a DSLR, even after a much longer exposure.

Carole 

 

Edited March 12, 2021 by carastro

[el_hop87]

Thank you Carole, that is brilliant! - can't believe its the same image!

Almcl- thank you again, I have never used StarTools so will try to learn this! 

The issue seems to be my lack of post processing skills which I will work on next! 

Thanks for being such a supportive forum and for all your help, really pleased that I posted in here.

[alacant]

11 minutes ago, el_hop87 said:

how you achieved this

Hi

Just follow the StarTools modules down from the top as I've indicated. It takes about 5 minutes. 

HTH

Edited March 12, 2021 by alacant

[el_hop87]

@alacant - brilliant, thanks, I will give this a go! 

[LordLoki]

its nice Data given how short your exposures are. did give it a quick go in Pixinsight. (yes the picture was created from your TIFF)

Cropped -> Dynamic Background Extraction --> Multiscale Median Transformation (to reduce noise) --> Histogram Transformation --> Extracted starless image with starnet --> Created Range mask from Starless image for the Nebula--> With Nebula protected Curves transformation to reduce saturation on Background and then also brought background down a bit on RBK --> Inverted mask upped saturation on Nebula (maybe bit to much) -- SCNR to get rid of a bit green noise. 

All in all 20 minutes + waiting for starnet to get starless image. 

Image21.tif

Edited March 12, 2021 by LordLoki

[el_hop87]

LordLoki- thank you! that is a great result and thank you for listed the steps you took, much appreciated! 

Alcant - did you have to change the TIFF file I attached to use it with StarTools - for some reason it wont let me open the TIFF. 

Thanks Elly 

[alacant]

1 hour ago, el_hop87 said:

change the TIFF file

Yes. Unfortunately DSS saves with tiff deflate. If using DSS, save in fits format. Or switch to a better calibration app;)

I converted your deflated TIF to uncompressed TIF using Siril. Not ideal.

StarTools uses the data, the whole data and nothing... etc. Nothing less will do.

Cheers

Edited March 14, 2021 by alacant

[el_hop87]

Thank you for this! - how did you convert the tiff file to fits format please? - the option doesn't seem to come up when I go to resave it.