Jump to content

Banner.jpg.b83b14cd4142fe10848741bb2a14c66b.jpg

M82, 81 & 106

Tzetze

By Tzetze
in Imaging - Deep Sky

Recommended Posts

Tzetze

Tzetze

Posted
Posted

Here's a couple of shots from over the last week or so. I'm not sure about the colour balance in these images. I'm shooting through a skywatcher light pollution filter with daylight white balance. In processing, I lined up the peaks of the colour channels. Should I bring the blue channel down some?

9x 600s subs

8275346386_1cbbf03b00_c.jpg

39x 600s subs

8275349324_ae163a1168_c.jpg

M106 09/12/12 by .Tzetze., on Flickr

450D, SW ED80, CG5, PHD-Guided

(50 darks, 25 flats and 50 bias in each image)

Link to comment
Share on other sites
  • Replies 27
  • Created
  • Last Reply
Astronut1982

Astronut1982

Posted
Posted

Very nice images Tzetze, I especially like the M106 one & the faint fuzzies you have captured.

I'm no expert but I think the reason they are a tad blue is because you have the wrong white balance set. The camera thinks that what it is seeing when you have the LP filter on is white but is actually tinted blue due to the filter. I use a CLS clip filter to solve my LP problem & my camera did the same until I solved it using a custom white balance.

To do this, I attached the camera to the scope & focus it as if imaging (I previously marked the focus tube on one occasion when I had accurately focused with a bahtinov mask) & then stretch a white T-shirt over the other end. Once this is done, point the camera at an evenly lit piece of clear sky, set the camera to Auto & take 2 or 3 images. Once this is done, go to the the white balance menu in settings & select custom white balance. The camera will then ask for an image as a reference so just select one of those just taken & it will use that as your reference. After all this is done, take an image in the same manner with your new white balance & you should now see that your colour has returned to normal.

What this process does is tell your camera that the blue you get when you image something that should be white, should actually be white so it recalibrates itself in order to remove the blue tint your LP filter has added to all your colours.

There may be better methods out there but this one works perfectly for me.

Hope this helps,

Jeff

Link to comment
Share on other sites
Tzetze

Tzetze

Posted
  • Author
Posted

Thanks very much guys. It seems such a long time since I captured those images, the weather hasn't been at all kind since then.

Mind if I ask if those are full frames or crops?

M106 is 30% of original frame. Heavily cropped.

M81&82 is 69% of original frame.

M106 was cropped heavily. The image is about 50% of the original frame. M81&82 is about 80% of the original frame

Very nice images Tzetze, I especially like the M106 one & the faint fuzzies you have captured.

I'm no expert but I think the reason they are a tad blue is because you have the wrong white balance set. The camera thinks that what it is seeing when you have the LP filter on is white but is actually tinted blue due to the filter. I use a CLS clip filter to solve my LP problem & my camera did the same until I solved it using a custom white balance.

To do this, I attached the camera to the scope & focus it as if imaging (I previously marked the focus tube on one occasion when I had accurately focused with a bahtinov mask) & then stretch a white T-shirt over the other end. Once this is done, point the camera at an evenly lit piece of clear sky, set the camera to Auto & take 2 or 3 images. Once this is done, go to the the white balance menu in settings & select custom white balance. The camera will then ask for an image as a reference so just select one of those just taken & it will use that as your reference. After all this is done, take an image in the same manner with your new white balance & you should now see that your colour has returned to normal.

What this process does is tell your camera that the blue you get when you image something that should be white, should actually be white so it recalibrates itself in order to remove the blue tint your LP filter has added to all your colours.

There may be better methods out there but this one works perfectly for me.

Hope this helps,

Jeff

Thanks very much Jeff. I was thinking a custom white balance would be needed. I've not done this before, thanks for the detailed instructions. I'll certainly try this next time out!

Good effort well done ;)

... treat yourself to an IDAS filter, I know they are expensive but they will transform your images..

Thanks Coco.

I'll look into that filter and add it to the ever-growing list. :)

Link to comment
Share on other sites
andyo

andyo

Posted
Posted

Hi just a post regarding the white balance.Now I am not 100% certain but fairly sure that altering the white balance on the camera to a modded white balance will have no effect if you take RAW images but will if the output is jpeg.However it is best to take RAW images and debayer with your software as this will give better quality images.To solve the white balance problem software programs like DSS have settings to reset the white balance-open up the raw/fits ddp settings (bottom left) and check the use auto white balance box.The blue tint can also be taken out by adjusting the histogram sliders in dss after it has stacked them.In Nebulosity after callibration debayering and stacking use the auto colour balance under the image dropdown box.Sorry I dont know about other software programs but I am sure they will have similar settings, hope this helps

Link to comment
Share on other sites
andyo

andyo

Posted
Posted

My custom white balance works & I have an astro modded camera. I only ever shoot in RAW & have never had a problem since I did the custom white balance.

Jeff

Sorry Jeff I stand corrected.i also have a modded canon 450 and wondered do you use the custom white balance for all your dso's and does it affect the sensitivity towards the red light.I am no expert and wondered if when you set the white balance to custom setting then it does the same to the additional red light it now receives after being modded as it does to the blue tint from the LP filter and recallibrates itself to remove this.This is a question I have not been able to find an answer to on various astronomy forums.Someone must know the answer to this.

Happy Christmas to you and your family

Link to comment
Share on other sites
Astronut1982

Astronut1982

Posted
Posted

Same to you Andy as well.

Yeah I use the custom white balance for all my DSO images. I must confess that I'm no expert either but I don't think it does affect the amount of red as whenever I post images, I'm normally told that they are too red. I have to admit that sometimes they are a little too red but there's not much I can do about it until I'm more experienced with PixInsight & Photoshop.

I've added 2 examples so you can see what I mean.

Jeff

post-16308-0-04251600-1356462875_thumb.j

post-16308-0-26029400-1356462894_thumb.j

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.