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M51 (first target for the new mount!)


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Very good for being new to astronomy...data looks good, but you do of course have to learn a lot when it comes to processing.

Did you do any processing other than DSS? Any color calibration or stretching in PS?

If you want to know how good your data is i suggest that you upload an uncompresed TIFF version so others can process it and show you what it can look like :)

Dropbox is a great way to share TIFF files. Remember to save in DSS with "do not apply adjustments to the saved image"

You have great gear so i'm looking forward to what you can make when you learn processing the data :smiley:

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Very good for being new to astronomy...data looks good, but you do of course have to learn a lot when it comes to processing.

Did you do any processing other than DSS? Any color calibration or stretching in PS?

If you want to know how good your data is i suggest that you upload an uncompresed TIFF version so others can process it and show you what it can look like :)

Dropbox is a great way to share TIFF files. Remember to save in DSS with "do not apply adjustments to the saved image"

You have great gear so i'm looking forward to what you can make when you learn processing the data :smiley:

Thanks for this. I know I have a lot to learn!!  I have stretched in PS and adjusted colour (on the second edit). What I was struggling with was keeping noise down when darkening image (during levels and curves adjustments).  I'll upload to dropbox the original file later for people to have a go.

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Don't worry to much about the noise right now, better to leave it till you learn how to deal with it without affecting parts of your image that aren't noisy.

A way to lessen the effects of noise is to not crop your image, when you share it the noise will be smaller and won't look that bad.

You might not be able too use that much of your images if you don't have a coma corrector or taking flats? 

If you don't have a way to easily take flats i can recommend the Huion L4S A4 light pad, it gets power from usb and is just big enough for a 8" scope.

A way to lessen the noise is to use dithering when guiding, this needs to be turned on in PHD and APT. This moved the mount a little for every dither and stacks out the non random noise in your images when you use kappa sigma stacking.

I made an image of M51 with a 6D and 8" newtonian a couple weeks ago and i think you should be able to get a similiar result after improvement in your imaing process and editiing process :)

No noise removal has been done on the image.

get.jpg

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It was taken on the skywatcher 200p as listed only with a Badder barlow in the train (perhaps a mistake but I was trying to increase the size of the image on the sensor). What settings do I need to change to dither? I've read about it and used kappa sigma stacking as I thought I was dithering!!  Also losing al colour in DSS, again prob got some option ticked incorrectly!

Love you're image btw! 

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Using the barlow is not a good solution for a DSLR and nebula/galaxies since you will be imaging at f/10 and need around 4x the exposure time to reach the same level of signal as at f/5. With DSLR and slower scopes the noise often overwhelms the signal and you end up with low details and lots of noise even in the brighter parts the your image.

If you want a smaller FOV you can crop the image during processing...my opinion is that with a 6D you should really take advantage of the hugh FOV it gives compared to a crop sensor or smaller CCD sensor.

To enable dithering in PHD go to tools and enable server. I'm not familiar with APT so i'm not sure how to enable it there, but shouldn't be hard to do.

What iso setting have you used? I suggest 800 and 1600. Also make sure to turn of all noise reduction options on your 6D. I suggest you try with and without darks. I have stopped to take darks, but it's a little colder in Norway than in the UK so might be different with you.

Don't worry about the loss of colors in DSS, after stacking the image in DSS you shouldn't change anything else, just save it with settings not applied and process it in other software.

To learn some basic photshop processing take a look at Doug German's basic processing videos.

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Thanks for the pointers. I've been watching those videos (several times! ) they're great! Will drop the barlow next time!

Been shooting at 1600 or 2000. Will be much better if I can avoid darks and maximise light frames for any given session.

I'll keep trying!

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I tried again last night!  No barlow this time. 43 no. 240s subs, 15 no. darks and 20 no. bias.  I've done a quick median stack (not kappa sigma) and 1 no. linear stretch and a 3 no. curve stretches little colour work in Photoshop. Final noise reduction in Lightroom. still learning and long way to go on processing but I'll hopefully have a bit longer to play with it later.  Happy to share the raw stacked TIFF if anyone else wants a go at processing!!

M51 Day 2 median stack (inc. darks & bias) quick stretch Edit

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Definitely much better:)

You are getting some of the fainter background galaxies here which is very nice.

Good tracking, pretty good stars (a coma corrector would make them perfect) and you are starting to get at least a little color after processing.

I could look at the TIFF later tonight if you share it.

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That would be great!!  Here's the link to the stacked .tiff unprocessed (other than stacking in DSS).  I would have sent it earlier but we have internet issues at the moment and it's taken 2 hours to upload!

https://www.dropbox.com/s/cbnboy6d7abi72i/m51%20day%202%20kappa%20sigma%20stack%20%28inc%20darks%20%26%20bias%29.tif?dl=0

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