Adreneline

I know this is a personal thing but I really like to see images of HH without the diffraction spikes.

This is a great image Adam - thanks for sharing.

Adrian

Hi vlaiv,

Thanks for clearing that up.

Adrian

2 minutes ago, vlaiv said:

apply some type of denoise algorithm after combining of individual masters

Hi vlaiv,

The PI forum article (the link I've sent) says in Warning (Note) 2 : "Do not combine denoised images. Signal-to-noise ratio (SNR) will be enhanced by combining noisy images and denoising the result. Combined images must be equally exposed, have the same pixel resolution, and be registered by projective transformation with no distortion correction."

The LV tutorial (  https://www.lightvortexastronomy.com/tutorial-narrowband-bicolour-palette-combinations.html ) advises the opposite - perform denoising before combining. That's why I'm confused.

Sorry if I am confusing you as well

Adrian

14 minutes ago, vlaiv said:

Can you give a link to second one - recommending denoising after channel combine?

This is the link vlaiv:

https://pixinsight.com/forum/index.php?topic=9206.0

Thanks for looking.

Adrian

4 minutes ago, wimvb said:

Usually if the data is good, it doesn't need noise reduction.

Hi Wim,

I agree entirely, but these two articles seem to be at odds - one says denoise before combining Ha, OIII, SII masters using PixelMath (or whatever) and the other says denoise after combining the individual masters.

I have a feeling it's all pretty marginal if the original data is good and you would be hard pressed to tell the difference as to when the noise reduction was performed. As you say, best to have good data and not to have to denoise and not to have to use deconvolution either!

Thanks for your response.

Adrian

Hi vlaiv

Many thanks for your reply.

27 minutes ago, vlaiv said:

I don't think this refers to channel combination.

The PI forum article was specifically about combining Nb images, e.g. Ha, OIII and SII, and using MureDenoise, making the point that individual masters should not be denoised prior to combining. The LV article mentions MLT but previous tutorials make it clear MLT is only one option, others include MureDenoise. Hence my confusion. The only thing in common is that images should be stretched to non-linear before combining.

Adrian

P.S. This is the link to the PI forum article: https://pixinsight.com/forum/index.php?topic=9206.0

So far when processing Nb images prior to combining as Bi-Colour or HST etc. I have followed the advice given in the LightVortex tutorials, namely "They have been fully pre-processed, have been registered with each other, have had background gradients removed with DBE and have been noise reduced with MLT...... in order to get the most out of colour combining these images, it is best they are stretched to non-linear".

I was nosing around on the PixInsight forum and came across a MureDenoise script for denoising linear monochrome images, where the advice given was  "Do not combine denoised images. Signal-to-noise ratio (SNR) will be enhanced by combining noisy images and denoising the result".

So now I'm confused - I think! What's the considered view on SGL? (a) pre-process, denoise, stretch and combine, or (b) pre-process, stretch, combine and denoise.

Adrian

16 minutes ago, Seanelly said:

but AdobeCC ($!) will have to wait a while, yet

Several years ago I was very, very fortunate to purchase PS-CS6 Extended Version for Mac only on an Education Licence and saved myself literally hundreds of pounds. I don't have PS on a PC but I have been experimenting with Affinity Photo - very much cheaper and very capable compared with PS. I am still having trouble understanding how to work with colour channels but layers is very much like PS. Might be worth a look

HTH

P.S. It's been cold here but nothing compared with the temperatures you folks are experiencing. I remember being in Pittsburgh 25 years ago when the Monongahela River froze over - that was pretty cold!

49 minutes ago, Seanelly said:

I have 8x5minute quality light frames

Sean, with my f2 Samyang 135mm and Atik428ex combination I can blow out the core with 20s LRGB exposures let alone 5 minutes.

I have found it a very difficult target to image successfully without recourse to layers in Photoshop to get an acceptable result.

I've tried a huge range of exposure timings from 5s LRGB up to 5 mins Ha/OIII/SII and most things in between.

M42 is a real challenge; however, it does provide you with plenty of processing experimentation on cloudy nights!

Adrian

Well this is how I see it using the two basic formula f = m * a and f = (G x M x m)/ (r^2) where in this case M is the mass of the Earth, m is the mass of a feather, or a man or an elephant, and r is the mean equatorial radius of the Earth.

So all objects fall at the same rate, i.e. acceleration due to gravity - neglecting air resistance.

Does that help - or confuse?

Hi,

I don't use heated clothing for AP but I do use heated clothing for motorcycling.

Sports Bike Shop are excellent : https://www.sportsbikeshop.co.uk/motorcycle_parts/content_cat/1391 : they also have an excellent returns policy if it's not suitable/doesn't fit. It's also not too bulky as it has to fit under other protective clothing. Many of the units can be run from pocket power supplies - some run off the bike itself. Worth a look maybe if only to get some ideas.

Adrian

Thank you Grant. All is back to normal now on Safari (MBP and iPhone).

Adrian

47 minutes ago, davew said:

If I am wrong please let me know.

I'll do some research. Have to say I hadn't thought about compatibility with BYEoS - I just assumed it would work!

I'm thinking of getting an M50 anyway and was just wondering if I could get some extra gearing from the purchase.

Thank you for your advice.

Adrian

Hi Everyone,

Just wondered if anyone had used a Canon M50 (or similar) for AP?

If so any issues with spacing, using filters, etc.

Thank you.

Adrian

42 minutes ago, Tiny Small said:

I ran into a few problems controlling halos around some of the stars

Hi,

Very nice image - I really like it.

You don't mention which processing software you used. I use PS to create Hubble Palette images (Annie's Astro Actions) and run into problems with magenta halos, however, I discovered there is a nice fix for it in PI using a PixelMath script (attached) I found on the PI forum. Apparently the same thing can be achieved using ColorMask under the Script menu but as yet I've not tried that method.

HTH

Adrian

remove magenta stars.xpsm

I'm G4NOV but very much QRT (non-operational) these days - all I have is a very old IC2E and I've not heard anything on that for years! I was always a big fan of RTTY and Amtor writing my own software for the BBC (now in the loft) and Archimedes (long gone to a new owner). I would be very interested to know/hear how you get on trying to have a contact with ISS. I was always impressed by amateurs who used meteor scatter for brief contacts using large, high-gain, steerable, multiple antenna arrays - the ISS sounds equally challenging.

Good luck!

Wow! I am seriously impressed. I am also impressed this feat of construction appears to be taking place in the lounge! But to be serious that is some undertaking and I only wish I felt I could do something similar. I'm currently trying to pluck up the courage to drill two holes in a Vixen bar - maybe tomorrow.

Good luck and I look forward to seeing the finished item.

Thank you for sharing and inspiring.

Adrian

I use Arcsinh a lot but in PI. I perform gradient removal first followed by colour calibration and then noise reduction before applying Arcsinh incrementally. I then use PS to pull out the colours. I presume the same process might apply in PS.

Adrian

Hi Oleg,

This is the version I use - running on a 2013 MacBook Pro.

My programming experience is very dated - 6502 processors on home computers, IBM8080 and Fortran IV on ICL1900 mainframes - all way back in the 1970's and 80's. Since then I've been a GUI 'wrapped in cottonwool' user I'm afraid.

I am currently trying to get to grips with Linux (via VirtualBox on the NUC) and programming an Arduino (via the MBP) and at my age it could be too much!

Thank you again for a very useful utility.

Adrian

I have Raw2Fits running under Ubuntu Astronomy within VirtualBox on a NUC-PC (I gave up with the MacBook!).

This is a really steep learning curve for a non-Linux person. I have tried the current version and it worked perfectly on my Canon raw files, converting them to individual RGB .fit files.

Thank you.

Adrian

If only I could get Ubuntu to run on my 2006 MacBook I would like to give your software a go - it looks very interesting.

Back to the MacBook

Hi!

Have you looked at one of these:

http://www.teleskop-express.de/shop/product_info.php/language/en/info/p5632_TS-Optics-50mm-f-6-6-APO-Doublet-Refractor---Day-Night-Scope-and-Tele-Objective.html

I've purchased from Teleskop-Express in the past and delivery is typically five days.

I've been considering upgrading my SW finder/guider on my ED80DS Pro ; AA scopes seem to be constantly out of stock/awaiting delivery. All very frustrating!