My first tentative with Orion constellation...

[gabs]

Hi all,

 

On Tuesday the 16th I tried my first tentative to take some pics of the Orion constellation with the intention to spot the Orion Nebula.

I will summarise the steps I followed and result achieved with the follow equipment :

CANON EOS - CANON EF 50MM LENS - LIGHT POLLUTION FILTER - REMOTE SHUTTER 

 

1) I took No. 12 exposures at 20 sec F5 ISO 800 ( with an interval of 2 sec each one )+ BIASFRAMES  No.12 same exposure, temperature etc + DARK FRAME same setting and FLAT FRAME  using my tablet screen;

2) I stacked the exposures into DeepSky Stacker . I got one frame saved saved as TIF ( IMG_3899 ) ;

3) on GIMP I opened the file as per screenshot attached (154028 ). Is the histogram correct or should I expect something better ?

4) When I start to adjust the colour levels then they start to appear the stars however there are tiny some red dots ( screenshot No. 155454 ) , why ?

5) when I zoom in in area where is should expect to see something , the result is what you can see in the last screenshot  ( 165644 ).

 

Please let me know what I did wrong and what right , if there is something correct !

 

Thanks in advance

Edited March 18, 2021 by gabs

[AstronomyUkraine]

The first thing I noticed, your channels are not aligned, hence the green cast. Instead of adjusting all 3 channels at once, adjust individually until they are aligned. Don't stretch the image using the right hand slider, use the left hand slider to adjust the black, and the mid tone slider to adjust brightness. Don't try to stretch the image all in one go, do it in stages, also make sure you don't clip the blacks by taking the left hand slider past the beginning of the curve.

[gabs]

Thanks ! 
 

with the assumption that all my first steps were correct , I mean exposure etc. Do you have a screenshot of what is suppose to be a good histogram with the correct channels so I can try to align them as per your example.

 

thanks in advance.

Edited March 18, 2021 by gabs

[AstronomyUkraine]

34 minutes ago, gabs said:

Thanks ! 
 

with the assumption that all my first steps were correct , I mean exposure etc. Do you have a screenshot of what is suppose to be a good histogram with the correct channels so I can try to align them as per your example.

 

thanks in advance.

All images will be different slightly, the image here is in Photoshop, but the principle applies in any editing software. Align the channels for correct colour balance, and don't clip the black.

 

[gabs]

I think I managed to get a better histogram but still a lot of work to do on it.

There is still a  kind of green green background all over the picture which seems to came from the clip filter ?

At the same time it seems stars are not perfectly focused as per my second screenshot or is that what I should expect to see at this stage ?

 

thanks.

[Carastro]

You last picture looks much better focus.   I am not sure why you are not getting a clearer image except that the stars are trails and quite possibly this also applies to the nebula so it is appearing smudged.  I believe you are using a static tripod.  i.e. one that doesn't track.

 

The green cast will be from the CLS filter, and you can balance the colours to rectify this as described above.  The three colours of the histogram should sit on top of each other as it looks in your last image post number 2.

 

The red dots, assuming that is exactly what they are = dots, are likley to be hot pixels.  All DSLRs get them especially when the image is long exposure and stretched.  There is a way to compensate for this by taking darks but I don't want to make you run before you can walk.

 

Carole  

 

 

 

 

[Carastro]

One other thing, if your camera is not Astro modified picking up some nebulosity will be more difficult than a Modified DSLR.

 

Carole 

[gabs]

Thanks a lot Carole,

Yes  I'm using a static tripod and the camera has the infrared filter so is not modified.

It seems is getting quite fundamental to use a sky tracker.

I want to try a different tentative : taking multiple shorter exposures in a different location where I don't need a clip filter. 

I am not sure but I think 20 sec exposure it's a bit too much is that why the stars start to trail.

Reducing the exposure should minimize the trails effects.

 

Thanks

 

[AstronomyUkraine]

10 second exposures would be your limit for imaging with a tripod, anything above that would leave star trails. To achieve better focus, set your live view to 10x zoom and find a bright star to focus on, focusing will be easier. With a 50mm lens, even bright stars will look like pin pricks, so find the brightest star possible. If you are shooting M42, the brightest star in the sky is close by, Sirius. If your camera has mirror lock, enable it, this will stop any camera shake, as you take images.

Edited March 19, 2021 by AstronomyUkraine

[gabs]

thanks a lot that is brilliant advise.

 

I will try again soon  or rather as soon as i have a clear sky.

 

is there any number of exposure i should take as minimun ? I know some people have taken up to 100 !

 

 

[MarkAR]

Just a quick thought, if you have a skylight or protective filter on the front of the lens it's best to remove it.

[gabs]

Hi Mark thanks for you comments.

 

I don’t think there is any filter or skylight filter in my lens.

 

I have attached pictures.

 

thanks

 

gabs

[Padraic M]

Hi Gabs,

Yours is similar to my first images of Orion, taken with a Canon 400D/ef28-135mm riding piggyback on my HEQ5, tracked but not guided.

EXIF tells me that it was at 28mm, 72sec, ISO1600. When you zoom in you can see that it is clearly out of focus with the telltale donut-shaped stars. The crop below is Orion's sword, so this is what you see for the nebula.  One frame only - I didn't know about stacking in those days.

 

 

I never managed to nail focus on the Canon, because my model doesn't have live view, and you can't see stars through the viewfinder.

 

I can't tell which model EOS you have, but apparently APT can do autofocus with Canon AF lenses if the camera is DIGIC III or higher. Autofocus is definitely the way to go:

https://astrophotography.app/usersguide/eos_lens_control_and_auto_focus.htm

Here's the APT Canon support matrix which lists DIGIC levels:

https://www.astrophotography.app/EOS.php

 

Also, as AstronomyUkraine mentioned above, if you're not using mirror lock, it may well be the cause of your star trails. On my model, mirror lock is custom function 7. I think you're using a remote shutter release which is also essential. Press the shutter release to retract the mirror, give it a few seconds to settle, then press shutter release again to open the shutter (then stand very still and don't breathe!!!).

This is the full image, so you know what to expect!

[gabs]

Thanks you Guys,

 

the camera is an EOS DC 5.1v so it doesn’t have a live view screen. 

I found the mirror locker function and is now enabled I have also found the noise reduction control for long exposure .

 

The good thing of this camera as I literally found it at home and no one used but it seems is not good enough for what I need or should I expect to get better result even without a live view? 

Thanks 

 

gabs 

[AstronomyUkraine]

4 hours ago, gabs said:

thanks a lot that is brilliant advise.

 

I will try again soon  or rather as soon as i have a clear sky.

 

is there any number of exposure i should take as minimun ? I know some people have taken up to 100 !

 

 

100 ten second images is only 16 minutes total. I would suggest 500 if your card is big enough. If you have an intervalometer, you can set the amount, and just leave the camera to take images. Turn off the noise reduction too. Dark images will do a better job of removing noise. You want images that have had no processing done by the camera. If you have no live view, focus on the moon first, if it is out, or focus manually in the daytime at a distant object, don't use autofocus. If your lens has stabilization, turn it off when using a tripod.

Edited March 19, 2021 by AstronomyUkraine

[Carastro]

Quote

 it doesn’t have a live view screen. 

Oh Crikey, you really are up against it trying to focus with no laptop and no live view.  

 

Also just to say you have a bit of a "catch 22" situation.  You are not tracking so you need to do short exposures to avoid trailing.  BUT the DSLR is not sensitive enough to cope with really short exposures.  

 

I am thinking you would be better off not taking your imaging kit to the park on your bike and concentrating on practicing imaging on your mount at home which tracks.  Just use the mobile set up for observing.

 

Carole 

[gabs]

Thank you Carole , AstronomyUkraine, Mark , Padraic M and everyone for your precious comments.

 

I know I am very bad and with a lots of limits but I won't give up for sure.

I will try again from my back garden , just camera tripod and remote shutter.

I hope to show you soon any progress.

 

Thanks so much for everyone .. I was a bit shy and embarrassed to show you what I've done but you have been through the same problems before me

[Padraic M]

Apparently it's a Canon EOS 350D, one generation older than my 400D so I suspect you will struggle to get much better results with it. 😞

 

[gabs]

Could someone advise a better camera for beginners ? 

 

Something affordable with view field and most of the details I need.

 

thanks.

Edited March 19, 2021 by gabs

[AstronomyUkraine]

25 minutes ago, gabs said:

Could someone advise a better camera for beginners ? 

 

Something affordable with view field and most of the details I need.

 

thanks.

That depends on what you call affordable. To make it easier to focus, look for a camera like the EOS 1300D with a flip screen.

[Carastro]

Look on Cheapastrophotography website.  He sells DSLRs already modified.  If you are buying a replacement you might as well get one already modified.  Definitely get live view, you will really struggle without.

 

I can't really recommend a model as I am really out of date with DSLRs.  I own a Canon 1100D and used to own a 450D but these are old models, but they still work fine.  No flip out screen though.

 

He sells second hand DSLRs already modified and I think new ones as well.  Lots of people have used him and always heard recommendations:

 

https://www.cheapastrophotography.com/Available-Cameras.html

 

Carole 

 

 

 

 

Edited March 19, 2021 by Carastro

[TerryMcK]

I agree with Carole. I have an even older 400D which produces excellent subs but it is very challenging without live view to focus for instance. I have a 650D with a flip out screen and live view which is far better. The 650D is not astromodded and I don’t use it for astro though.

So anything from the 650D and newer would be my recommendation but get one with a flip out screen as some of them don’t have one.

[gabs]

Thank you both!

I am having a look to his web site and get in touch with the seller once I found what I need

 

Thanks a lot!

Gabs

[PeterBolt]

You might find this article useful:

 

https://www.skyatnightmagazine.com/top-astronomy-kit/best-astrophotography-cameras/

 

Towards the end of the feature they list their best 18 cameras for starting Astrophotography.

 

The 1000D is a good place to start and I have been using one since the summer of 2020.    It has live view but not a flip out screen.  The pixel size is also more forgiving for beginners so I have been told. I sent mine off to cheapastro to be modified and can highly recommend his service.  

 

Maybe also have a look at BackyardEOS software.  I find it very helpful for finding focus.   But it does mean you have to add a laptop to you kit.

 

Hope this helps.  

Edited March 20, 2021 by PeterBolt

[gabs]

Thanks Peter much appreciated your link and comments,

 

I have contacted cheapastro seller to his email address and found other private seller on eBay for a EOs1200d.

 

I am trying to compare two different options 

Thanks again.

 

gabs