Very over exposed looking subs and particularly poor final image :(

[TiffsAndAstro]

14 minutes ago, Elp said:

You really need to spend more time on target, the above is an improvement. You can see the flame nebula in your above and that's from 17 minutes. Spend up to 3-5 hours and you'll see a lot more, even the horse head nebula next to the flame. You can stack your unstretched stacks per session (as the simplest method, they have to still be in linear state) to combine your multiple session exposure time.

Adding more and more time will help lower the read noise in the stack but won't eliminate it completely, all DSO smooth images have had a noise reduction applied to them post process.

im not expecting to rival the jwt but i'd like to see some progression orion is gettting lower by the day, but its possible i can get some of it tonight. 

i really do appreciate everyone's input and help ty again.

also - only had a little play with siril's noise reduction and i don't like the results. hopefully just means i need more experience with it. the green noise reduction seems to work well mostly. 

Edited February 23 by TiffsAndAstro

[Elp]

Trust me, because your camera is unmodified you really really need to spend longer on target when imaging emission nebula. Orion is easy, you can usually capture it with 5s exposures, but to capture the outer regions and especially the nearby horse head nebula you need more time. To put this into some sort of perspective for you, with my modded 600D I could faintly see the horsehead and the red running off from it with a single 2 minute exposure without editing the image in any way.

[TiffsAndAstro]

57 minutes ago, Elp said:

Trust me, because your camera is unmodified you really really need to spend longer on target when imaging emission nebula. Orion is easy, you can usually capture it with 5s exposures, but to capture the outer regions and especially the nearby horse head nebula you need more time. To put this into some sort of perspective for you, with my modded 600D I could faintly see the horsehead and the red running off from it with a single 2 minute exposure without editing the image in any way.

would 10 x 107sec subs show more details than 107 x 10sec subs, do you think? i know its not an easy question to answer though.

[Elp]

18 minutes ago, TiffsAndAstro said:

would 10 x 107sec subs show more details than 107 x 10sec subs, do you think? i know its not an easy question to answer though.

No, not significantly, total time is what counts. From the above the latter image will be a noisier stack as it will contain 107 samples of your cameras sensor read noise whereas the former 10, being a camera body it'll also run hotter than a cooled astro camera so the noise level will be slightly higher.

A filter may help the emission and background separation, like an L-Enhance/Extreme/Ultimate for hydrogen alpha and oxygen iii rich nebulae (Optolongs), there are many others now on the market too, but try without first.

If you want a wow target with your existing kit as it is go for M31 Andromeda Galaxy or M45 Pleiades star cluster, but you still have to spend hours on target, not minutes. And the end result will greatly (like 70-80pc of the work) depend on your post processing image editing skills.

[TiffsAndAstro]

Ty for the advice, but m31 is too low will look for m45 though and give it a go. 

Pleides probably out of view before orion cant check until later.

 

so too many clouds last night. might be similar tonight, if it is ill try a proper full polar alignment, at least i can practice that. If clear, will try pleides then orion. should have two hours when they are visible for me.

Edited February 24 by TiffsAndAstro

[TiffsAndAstro]

set up full polar aligned, it fact went so easy seems too good to  be true. doing 60sec exposures atm just hoping someone can check my image for any obvious problems? there's cloud in this image and it looks a bit oxer exposed but don't want to drop iso below 200.

 

 

i should set picture style to neutral ?

Edited February 24 by TiffsAndAstro

[happy-kat]

It looks like still +3 on exposure compensation but I'm not sure

It might be for your imaging location and light pollution you'll have to try 45 seconds

Edited February 24 by happy-kat

[TiffsAndAstro]

21 hours ago, happy-kat said:

It looks like still +3 on exposure compensation but I'm not sure

It might be for your imaging location and light pollution you'll have to try 45 seconds

just in case i set picture mode back to neutral so its 0 0 0 0 ty   im tempted to find a reset to defaults and give it a go

last night was covered with thin high cloud i couldn't see it until i loaded the subs onto my pc. still i had a chance to do proper polar alignment via synscan app and it seems im a god at PA.

which is unlikely. is there a way in the synscap app to see how accurate it thinks i am and can even test it? 

Edited February 25 by TiffsAndAstro

[TiffsAndAstro]

here's a random .cr2 file, 135mm f4 60 sec (i think it was - need to make better notes as i go along)

 

seems andromeda might be visial tonight so ill try an hour on that an hour on pleides and an hour or as long as poss on orion

IMG_6399.CR2

[TiffsAndAstro]

90 x 60sec subs with a 500mm mirror lens. its sort of ok, but i think i could do better. full moon light pollution and cloud dodging.  

[happy-kat]

you can see clerly what the DSO target that's great

Using siril I created a starless image, then used star recomposition and merged the stars back and they are rounder now, there's more tweaking you could do but that was a quick change for you

edit: I  see star removal ate a star or two

 

Edited February 26 by happy-kat

[TiffsAndAstro]

37 minutes ago, happy-kat said:

you can see clerly what the DSO target that's great

Using siril I created a starless image, then used star recomposition and merged the stars back and they are rounder now, there's more tweaking you could do but that was a quick change for you

edit: I  see star removal ate a star or two

 

Slander. I think much much more likely I discovered a new black hole or two

 

Honestly, in the scheme of things it's a crap image. But it's my first go at m51 and with a 14yo camera and 25 quid mirror lens

 

Might be clear tonight might give it a go at 135mm f2.8 and/or 200mm f4.5

 

I'm guessing I'm suffering from a common noob thing of being a kid in a candy shop and not concentrating on one target, but dodging clouds, roofs trees and accounting for rotation and how long I have to shoot is tricky

Edited February 26 by TiffsAndAstro

[Elp]

You have to change your mindset. I was the same at one point and with an F2 telescope setup I can still do multiple targets in a night if I wanted to but I don't. If you want quality you HAVE to dedicate and accumulate the hours per target, unless you wish to do EAA which I assume you don't.

Edited February 26 by Elp

[TiffsAndAstro]

1 hour ago, Elp said:

You have to change your mindset. I was the same at one point and with an F2 telescope setup I can still do multiple targets in a night if I wanted to but I don't. If you want quality you HAVE to dedicate and accumulate the hours per target, unless you wish to do EAA which I assume you don't.

well my plan tonight is hh flame and orion (getting them all in shot if i track alnitak) as soon as it goes dark to as soon as they drop below neighbours house. maybe 7pm to 1030 pm. 135mm maybe at f2.8 but may stop it down if it helps star shape. maybe 60sec at iso400 again

Edited February 26 by TiffsAndAstro

[TiffsAndAstro]

So only thin usable from last night was 2 hours on alnitak trying to get "everything" in frame. Which I did but dpnt like

4mins stacking maybe 10 minutes processing I'm pretty happy. M42 core not too blown out but weird processing artefacts if you zoom into core.

Vintage 135mm f2.8 iso400 unmodded 600d moon not up.

[Elp]

Getting better. You can see the horsehead (ic434) and also the reflection nebula m78.

 

[TiffsAndAstro]

50 minutes ago, Elp said:

Getting better. You can see the horsehead (ic434) and also the reflection nebula m78.

Ty this is the first thing I'm happy with after 10 maybe 12 hours practice.

 

[TiffsAndAstro]

Ty after 10 to 12 hours this is the first image I'm happy with.

 

[TiffsAndAstro]

21 minutes ago, TiffsAndAstro said:

 

I really would like the horsehead tonight if clear ish.

Might do quick experiment on it with my mirror and 200mm f3.5.

Maybe andromeda before it drops too loo?

 

[Elp]

You can try Andromeda.

For better results you should really keep imaging the same framing over multiple nights until you have a few hours (say 3-5 hours). Then stack each stack together, it'll give you an even better result than doing just one quick session.

[TiffsAndAstro]

1 hour ago, Elp said:

You can try Andromeda.

For better results you should really keep imaging the same framing over multiple nights until you have a few hours (say 3-5 hours). Then stack each stack together, it'll give you an even better result than doing just one quick session.

i know you speak truth, but i want to try everything. when i'm bored of everything i can try and do something a bit better

m31 tonight now i've realised i can see it for a couple of hours before house roof

i will go back to orion though, mainly because its amazing. i really haven't looked into stacking multiple night's exposures, so a few hours on one target per evening will do for now. 

here's a bluer version of the same image btw lol. didn't think i did much different but there you go lol

i prefer the colours of the earlier one, but this is still quite nice.

tbh, im still in shock a 15 dollar 40 year old lens can do this. 

 

 

[TiffsAndAstro]

On 22/02/2024 at 23:11, mackiedlm said:

There is something going on between image capture and saving the image as CR2. Are you sure you disabled any in camera processing.

Taking the last image you uploaded from last night IMG_5291.CR2;

When I open in Photoshop camera raw, I get this

 

Note the histogram , data in middle. The image is still very bright. A properly exposed astro CR2 will be very dark.

 

If I open that same image in Pixinsight and debayer, This is what I get without any stretch applied;

 

This is exactly what a reasonably well exposed unstretched astro image should look like, Note the histogram way to the left (on a moonless night it would likely be further to the left.

If I apply an automatic stretch with STF I get this

 

Again this is exactly what I'd expect from this camera, lens, no filters, a bright moon, 30s @ISO400 - based on what I get with my 700D, The gradient is almost certainly from the moon and other LP and would be easily handled in the stack using any form of gradient removal.

 

In my opinion, there is some processing imbedded in the .CR2 which Photoshop uses to produce what it does. PI does not understand that imbedded information and opens the true "raw" image.

You need to work out what is happening in camera and stop it. Or else try stacking the subs in pixinsight.

But as long as you shoot with that camera and fast lens un filtered, in full moon conditions, you are going to have live with those terrible gradients and the other issues related to the bright moon LP

Also, I'd just note that stopping down has done little to improve the coma/abberations from the lens. They are still very bad. this is a zoom in to the top left corner.

 

HTH

maybe i like seaguls? sorry for a late reply, only just noticed this.

will have a go stopping down, but right now i want experience/time gathering data, even if its a bit crap data

hopefull stopping down will clear that up might be able to test that tonight ty

 

[TiffsAndAstro]

19 hours ago, Elp said:

You can try Andromeda.

For better results you should really keep imaging the same framing over multiple nights until you have a few hours (say 3-5 hours). Then stack each stack together, it'll give you an even better result than doing just one quick session.

best i could manage last night about 1200seconds i think. those angels/seaguls are getting annoying  ignore the file name pretty sure this was wide open at f2.8. next break in clouds will try stopping down the same lens to F4 or even 5.6 see if this scares away the seafuls.

[Elp]

Is that the same setup as before?

There's something odd going on, it's more than coma from the lens, the Andromeda one shows the coma going in one sort of direction so it looks like there's some sort of tilt also between lens and camera. Coma if present should radiate outward from the centre of the lens near the edges.

The focus in the image is kind of off too so it'll show lens issues more.

[TiffsAndAstro]

10 hours ago, Elp said:

Is that the same setup as before?

There's something odd going on, it's more than coma from the lens, the Andromeda one shows the coma going in one sort of direction so it looks like there's some sort of tilt also between lens and camera. Coma if present should radiate outward from the centre of the lens near the edges.

The focus in the image is kind of off too so it'll show lens issues more.

the andromeda image was a vintage 135mm f2.8 60sec subs for about 20 minutes total. Im going to try the same shot but longer as soon as it is clear and use same set up except ill try stopping down and see if it helps with the angel star shapes.  

any criticism is warmly welcomed so tyvm

 

also turns out my polar alignment was not as good as i thought it was. will do it properly asap and try stopping down the 135mm a bit. 

i will focus on using just that one lens as the focal length seems a decent balance between ease of seeing stuff and being a bit more zoomed in

Edited February 28 by TiffsAndAstro