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First light with imaging setup

milan

By milan
in Imaging - Discussion

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milan

milan

Posted
Posted

So last night was the night, all the bits of the expensive jigsaw were in place so i brought everything down from upstairs where the lit has been living for the last week and a half since its been cloudy.

Now ive only setup an EQ mount once before, which was when i setup the polar scope and reticule etc so i was really chuffed that i found it really easy to setup and it took no time at all to assemble the mount get the scope on, balanced, polar aligned using the setting circles :) and get a 3 star align.

So here are some piccies of it all setup:

660196101_KzfJq-M.jpg

660196113_ZqBau-M.jpg

I then realised that i only balanced the scope with the diagonal and eye piece and not the camera, should i go balance with the camera on? If so wont this put the alignment out when i 3 star align? I decided however to press on.

So the first problem encountered was that my 5D was too heavy and the focuser couldnt take the weight. So after much looking around the scope and not being able to find what i thought was the right allen key head to tighten it i turned to this forum, having also tried reducing the weight by taking off my battery pack. Much fun ensued as i eventually found out that the allen key head i was looking for was under the damn WO quality control sticker! :)

http://stargazerslounge.com/equipment-help/88012-how-do-i-adjust-megrez-90-focuser-tension.html

:o

So next up was focusing, now this i was expecting to be both time consuming and difficult, however i was again pleasantly suprised. Having initially focused by looking through the view finder i put the Bathinov mask on (VERY impressed with the mask received from stay focused) and took my first image of 'Tsih' I zoomed in on the image and found i was actually pretty well focused and the central diffraction spike was pretty much there. I did however have a bit of a play to work out what did what. 12 shots later i was in focus.

So i decided to aim for the M31. So i took a few test shots of varying duration at ISO 800 and viewed the histogram. The histogram showed that the light was in the left third which i read somewhere was about right on 60 second subs. 90 second subs were getting close to the middle of the histogram.

So i set my remote shutter up to take a succesion of 60 second subs with a 30 second gap between exposures and hit the start button. I only managed to capture a total of 10 as some high level cloud decided to appear from nowhere which put a stop to play. :D I then put the cap on and captured 5 darks of the same duration as the clouds rolled over

The following image is a single 60 second sub straight out of my 5D (shot in RAW), note the nasty orange tinge i asked about. The image is not cropped or processed in anyway.

659921169_Mzt3E-M.jpg

So it was about 12.30 when the cloud appeared and being keen i decided to have a play with the images. I downloaded 'Nebulosity' installed and fired it up having only briefly looked at the manual many months ago it was all a bit daunting. So after jumping straight to the page about 'stacking darks', making masters and 'bad pixel mapping' i moved onto the lights (i dont have any flats yet). I followed the steps in the manual and stacked my 12 lights. I was looking for a step that used the 'dark master' durign the process and somehow overlaid it but there didnt seem to be one, does this happen automatically?

So after much experimentation, polar aligning an EQ mount for the second time ever, sorting the focuser tension, obtaining focus and diving into a complex piece of software that i have never used before i ended up with the following image of the M31 at 2am this morning made of 12 x 60 second lights and 5 x 60 second darks:

(Excuse the vertical lines but ive not yet purchased a licence for Nebulosity so it saves images with lines on in demo mode)

659965813_UJqZA-M.jpg

Note that this isnt cropped and probably not very well post processed (thats a whole other learning curve)

Now i know its not exactly the best image on here of the M31 but given the huge learning curve last night im pretty chuffed with myself. Its supposed to be clear tonight as well... :)

So then, the inevitable questions:

Should i balance the scope with the camera on? does it make much difference as your only likely to image one object per session so the scope wont move much, only track.

The image taken seems not really contain much colour, is that just due to the limited number of subs and their duration i have taken? or something at the processing stage?

Whats the best way to get some flats? shot a white piece of paper sometime during the day? how many should i be looking at?

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Aza

Aza

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Sounds like you have done incredibly well for a first night, especially as yo have not used the mount either. Just goes to show what reading and being prepared can do for you :o

I would suggest using Deep Sky Stacker for stacking the images for the time being. Its a lot easier to use, and does everything automatically. In Nebulosity, can you have to do things in a few stages which can over complicate things at first. Although be aware that the image DSS spits out can look very dark. Dont take this for DSS being broken. Load the image up into a graphics program afterwards.

1) You should balance the scope with the camera on, as this is the configuration and weight at which you will be imaging.

2) Your image is incorrectly stacked, try DSS :)

3) For flats you can make yourself a lightbox like I did (Light Box). Or you can take them using the sky. For this get a plain white t-shirt, and stretch it over the scope. This will defuse the light. Point the scope away from the sun at an even patch of sky.

When you expose the shots aim for histogram peak to be at about the halfway position, this will be a shot of less than 10 secs each (mine are usually 1 second). Take 20-30 of these.

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milan

milan

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Sounds like you have done incredibly well for a first night, especially as yo have not used the mount either. Just goes to show what reading and being prepared can do for you :o

I would suggest using Deep Sky Stacker for stacking the images for the time being.

1) You should balance the scope with the camera on, as this is the configuration and weight at which you will be imaging.

2) Your image is incorrectly stacked, try DSS :)

Thanks, did a lot of reading on here with the wealth of information that is available, so its all down to you guys :D

1. Problem i have is that we are a Mac household (although i do have an old PC knocking around, which i could potentially setup) so DSS was out of the question last night.

2. Could you expand further on that point? How so?

3. Just had a quick look and it appears that there isnt a CLS filter that fits a Canon 5D, what other options do i have?

Thanks :)

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Aza

Aza

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Its been awhile since I stacked using Neb.

Just fired it up though and I think this is what to do:

1) Align and combine your darks using the NONE method, to create a master dark.

2) Pre process B&W/Raw Images (Here you select the master dark and light frames)

3) Batch Demosaic + Square raw colour (use this on the pre processed frames from step 2)

4) Align and combine Translation plus rotation on the frames from step 3.

If you can get DSS working it does all this automatically! Including aligning the frames.

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Beyond_Vision

Beyond_Vision

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A great first light Milan you have managed alot more than most on your first night. With regards the filter if you are using a 2" nose piece on the DSLR you can screw a 2" filter into it. I would go for a Neodymium filter which will tackle the sodium light pollution but will not leave too much of a colour cast to get rid of in processing.

Have you got a windows emulator for the Mac you could then run DSS?

Regards

Kevin

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arad85

arad85

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this hobby is a money pit!
Ha ha ha... Not only do you have to buy the equipment, you also have to have peripheral stuff to make it all worthwhile. I'm thinkingof upgrading my laptop so it can cope with a better camera (I've a hankering for a DBK21/DMK21) but I'm also considering buying a new monitor and pen/tablet so I can calibrate it properly and have good enough picture quality so I can properly process the images I get back... Another £500-£600 there :o

Great start by the way :)

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Aza

Aza

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I posted further up how you should be stacking using Nebulosity.

Although this is when I captured using Neb, and the saved images were fits.

Did you try it? Here it is again:

1) Align and combine your darks using the NONE method, to create a master dark.

2) Pre process B&W/Raw Images (Here you select the master dark and light frames)

3) Batch Demosaic + Square raw colour (use this on the pre processed frames from step 2)

4) Align and combine Translation plus rotation on the frames from step 3.

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arad85

arad85

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Hi milan,

Exposure. You've imaged 12 minutes of data (at 60secs). Take a look at other peoples photos of M31. For example here: http://stargazerslounge.com/imaging-deep-sky/87339-m31.html (3 hours data), here: http://stargazerslounge.com/imaging-deep-sky/87688-m31-done.html (5 hours 10 mins), here: http://stargazerslounge.com/imaging-deep-sky/87602-yet-another-beginners-m31.html (2 hours). There are others, but they were the first 3 I could find.

This deep sky stuff takes a lot of work :o

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milan

milan

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Thanks both. It was late but im pretty sure that is the routine that i followed in the instruction manual but will check later this evening.

Also just found 'keiths image stacker' for mac so will give that a whirl also and let you know how it goes.

I assumed it was the amount of data had (or dont have) that was the problem having seen a few of those posts early this morning. Thanks for the clarification though.

I posted further up how you should be stacking using Nebulosity.

Although this is when I captured using Neb, and the saved images were fits.

Did you try it? Here it is again:

1) Align and combine your darks using the NONE method, to create a master dark.

2) Pre process B&W/Raw Images (Here you select the master dark and light frames)

3) Batch Demosaic + Square raw colour (use this on the pre processed frames from step 2)

4) Align and combine Translation plus rotation on the frames from step 3.

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arad85

arad85

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Well your stacked image is mono.
Oops... I've been fiddling with my second monitor (which is where my web browser is at the moment) settings and only just realised that the black level was set way too high. Didn't notice the no colour - just thought there was no detail. Amazing how much more detail you can get if you reset your monitor profile :o:o
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milan

milan

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You cant select option 2 below for lights, confused. Only get option of Dark, Flat and Bias in Nebulosity

Darks = black images with cap on

Flats = image of piece of white paper

Lights = images of object you are photographing such as M31

Or am i getting confused!?!

Its been awhile since I stacked using Neb.

Just fired it up though and I think this is what to do:

1) Align and combine your darks using the NONE method, to create a master dark.

2) Pre process B&W/Raw Images (Here you select the master dark and light frames)

3) Batch Demosaic + Square raw colour (use this on the pre processed frames from step 2)

4) Align and combine Translation plus rotation on the frames from step 3.

If you can get DSS working it does all this automatically! Including aligning the frames.

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milan

milan

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Ack, totally lost with getting colour out of the image with curves, DPP etc. Im used to curves and all but not really sure what im trying to achieve!

I keep ending up with funny hues on screen for some reason. Could be time to boot up the old PC :o

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Aza

Aza

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You cant select option 2 below for lights, confused. Only get option of Dark, Flat and Bias in Nebulosity

Darks = black images with cap on

Flats = image of piece of white paper

Lights = images of object you are photographing such as M31

Or am i getting confused!?!

You select the darks and flats, then continue, and it then asks for the lights :o

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