L-Extreme...Too extreme ?

[DroneSaif]

Hi all. Need some help please.

I live in a Bortle 8/9 area, in Riyadh, KSA. So to try and do some imaging from my roof top I bought the Optalong l-extreme. As a light pollution filter this filter may be a ..Little Extreme. I have attached a single sub of 600 seconds exposure just to show how extreme it is. They are both the same file, one is auto stretched, and the other isn't. I just removed the green colour cast on both. This is supposed to be M8- Lagoon Nebula. i had similarly underwhelming results from M105 and M85/M86.

I am not sure what I got wrong. Did i just choose the wrong targets for l-extreme ? if so, can anyone suggest a target visible from the northern sky right around 24 degrees ?

Or is 600 seconds is still not enough (!!!)

Or is there something else I should do?

My equipment are as follows :-

Vixen FL55SS - 314mm F/5.7 (inc Flattener)

QHY294C Pro

AZ-GTI in EQ mode

EKOS on Astroberry

PHD2 single star tracking.

Thanks

[michael.h.f.wilkinson]

The L-eXtreme filter is really intended for narrow-band objects, i.e., emission nebulae and planetaries, not galaxies, and certainly not elliptical galaxies which lack H-II regions. This was obtained on the Rosette with teh L-eXtreme

[ollypenrice]

As Michael says, this is an emission Nebula filter but I think you should have had some success with the Lagoon which is quite strong in Ha. I've imaged it easily from my dark site with an OSC camera unfiltered.

You say one image is autostretched but I don't know what this autostretch process is. It hasn't stretched the stars so why would you think it had stretched anything else? Does the nebulosity show if you stretch manually in the usual way (eg Levels and Curves in Photoshop? And has it been debayered for colour? It doesn't look as if it has. This may just be a software/image extraction problem.

Olly

[vlaiv]

OP says that above image is M8 Lagoon, and that is emission target / Ha region.

I think that something is wrong with filter or the way it is used.

Other than that - maybe M8 is very low at the moment, or was shot at wrong time - but I have no idea what's the visibility like in Riyadh at the moment, or what altitude M8 reaches right now.

[vlaiv]

Just checked, at the moment M8 reaches 41° at 3:15am local time (GMT+3) and can be imaged prior to that as night ends at about 4am

When was M8 imaged?

[DroneSaif]

On 02/05/2021 at 13:26, michael.h.f.wilkinson said:

The L-eXtreme filter is really intended for narrow-band objects, i.e., emission nebulae and planetaries, not galaxies, and certainly not elliptical galaxies which lack H-II regions. This was obtained on the Rosette with teh L-eXtreme

Thanks for the suggestion. I will see if Rosetta is something Incan try next. 
 

care to share some exposure details not this photo? 

[DroneSaif]

On 02/05/2021 at 14:28, vlaiv said:

Just checked, at the moment M8 reaches 41° at 3:15am local time (GMT+3) and can be imaged prior to that as night ends at about 4am

When was M8 imaged?

That’s from two nights ago. I suspect, (nay I am pretty sure) I may have been imaging the wrong part of the sky. 🤗

[DroneSaif]

On 02/05/2021 at 14:14, ollypenrice said:

As Michael says, this is an emission Nebula filter but I think you should have had some success with the Lagoon which is quite strong in Ha. I've imaged it easily from my dark site with an OSC camera unfiltered.

You say one image is autostretched but I don't know what this autostretch process is. It hasn't stretched the stars so why would you think it had stretched anything else? Does the nebulosity show if you stretch manually in the usual way (eg Levels and Curves in Photoshop? And has it been debayered for colour? It doesn't look as if it has. This may just be a software/image extraction problem.

Olly

I stack using SIRIL and it has an “Auto stretch” feature. Not sure what it does, I’m afraid. 😌

[DroneSaif]

On 02/05/2021 at 14:21, vlaiv said:

OP says that above image is M8 Lagoon, and that is emission target / Ha region.

I think that something is wrong with filter or the way it is used.

Other than that - maybe M8 is very low at the moment, or was shot at wrong time - but I have no idea what's the visibility like in Riyadh at the moment, or what altitude M8 reaches right now.

I had thought that M8 Lagoon is a suitable target.  
 

But some people pointed out that maybe I was imaging the wrong part of the sky. 
 

I was using EKOS to plate solve and maybe I did not choose the “slew to target “ option. 🤷🏽‍♂️

[michael.h.f.wilkinson]

55 minutes ago, DroneSaif said:

Thanks for the suggestion. I will see if Rosetta is something Incan try next. 
 

care to share some exposure details not this photo? 

I took a huge load of 60 s subs at ISO 800 on my Canon EOS 550D (modded). The Rosette is some 12 hours 21 minutes total exposure time. I was shooting at 384mm focal length, F/4.8. Darks, flats and dark-flats all applied. 

[vlaiv]

2 hours ago, DroneSaif said:

I had thought that M8 Lagoon is a suitable target.  
 

But some people pointed out that maybe I was imaging the wrong part of the sky. 
 

I was using EKOS to plate solve and maybe I did not choose the “slew to target “ option. 🤷🏽‍♂️

I guess that is mystery solved then. Probably the same thing with M105 and others, but do keep in mind - this filter is not suitable for galaxies - only emission type nebulae.

[ollypenrice]

Always do a test shot to see if you're on target. Besides, the plate solution won't necessarily give you the best composition in terms of stars around the edge of the picture. This is quite important when it comes to the visual appeal of the final result. You can also end up with flares from out-of-shot stars. If this happens, drive the mount towards the out-of-shot star and the flare may vanish.

Olly

[DroneSaif]

22 hours ago, michael.h.f.wilkinson said:

I took a huge load of 60 s subs at ISO 800 on my Canon EOS 550D (modded). The Rosette is some 12 hours 21 minutes total exposure time. I was shooting at 384mm focal length, F/4.8. Darks, flats and dark-flats all applied. 

Thanks for the info!

[DroneSaif]

20 hours ago, vlaiv said:

I guess that is mystery solved then. Probably the same thing with M105 and others, but do keep in mind - this filter is not suitable for galaxies - only emission type nebulae.

Yes I understand that. Now making a list of a good targets. Any suggestions? 

[DroneSaif]

17 hours ago, ollypenrice said:

Always do a test shot to see if you're on target. Besides, the plate solution won't necessarily give you the best composition in terms of stars around the edge of the picture. This is quite important when it comes to the visual appeal of the final result. You can also end up with flares from out-of-shot stars. If this happens, drive the mount towards the out-of-shot star and the flare may vanish.

Olly

Thanks for the tips! Appreciate the input 

[vlaiv]

3 hours ago, DroneSaif said:

Yes I understand that. Now making a list of a good targets. Any suggestions? 

Get yourself a copy of Stellarium application.

It is planetarium application that will show you what is in the sky for your location and selected time.

Look at the symbols that I marked. Green squares denote emission type nebulae / HII regions. Circles with little spikes denote planetary nebulae.

These are types of targets that you are interested in. Planetary nebulae are usually small in size - so go for "squares" rather than circles with spikes

You'll have additional info (size, brightness and such in top left corner once you select your target).

[DroneSaif]

On 05/05/2021 at 12:04, vlaiv said:

Get yourself a copy of Stellarium application.

It is planetarium application that will show you what is in the sky for your location and selected time.

Look at the symbols that I marked. Green squares denote emission type nebulae / HII regions. Circles with little spikes denote planetary nebulae.

These are types of targets that you are interested in. Planetary nebulae are usually small in size - so go for "squares" rather than circles with spikes

You'll have additional info (size, brightness and such in top left corner once you select your target).

Thanks very much!

 

Will check it out