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Galactic Centre Luminance Mosaic 5x5 at 530mm


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Hi Again, While the Luminance for the mosaic didn't quite work out at 5x5 panes, due to the Eagle getting its wings clipped, I had to add another row to the top. I missed the final pane in the top right. This is something I hope to finish soon, and which will will then give me a wider view of the top, allowing the eagle lots of room to flap. Anyway in this version I have managed to angle a crop to get the Eagle, just about, in the frame. So now this just leaves the final 3 rows of RGB, or I guess 4 rows really. This is 60mins Lum per pane, and a crop of 29 frames. Taken with the Tak FSQ106N and Atik 11000, between May 2012 and June 2013. While this region has been done before by Rogelio, and the phenomenal 50 pane picture from Stephane Guisard, both were taken with the focal reducer, so while I can't match Stephanes picture for data, this is of a higher resolution. Another one for the wall at home if I can find a wall big enough. Even though there is only an hour per pane, this is a bright region of the sky so there is a good signal present. Stitching was done by creating a base layer with Star Align in Pixinsight. Then using Gradient Merger Mosaic, I created a better more accurate base layer from the star aligned files. I then had to go to Registar to individually match each pane to the base layer, which I then stitched together in CS2. The same GMM PI base layer was then used for the RGB panes to match to in registar. So despite some small areas where the join was not perfect, I do hope to be able to combine the RGB data, and the Lum as 2 huge but separate layers either for PI or PS. This will help a lot with colour saturation, balancing the image for brightness, contrast, and sharpness etc.. I've posted an image on Flickr which might be a bit larger than this attachment. http://www.flickr.co...N02/9157592351/ There are lots of beautifully shaped dark nebulae in the image, open and globular clusters and even small planetary nebulae in there that I did not notice until I went to check the stars charts.post-4679-0-99451500-1372429731_thumb.jp

Edited by Tom OD
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Absolutely incredible, Tom... I've been struggling matching backgrounds on just a 4x3 mosaic (some gradients occasionally crept in due to moonglow) and that experience is teaching me never to go beyond 2x2 in future! I imagine that dealing with 25 panes introduces all sorts of additional complications... not least are which are file sizes, especially using an 11000?

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Absolutely incredible, Tom... I've been struggling matching backgrounds on just a 4x3 mosaic (some gradients occasionally crept in due to moonglow) and that experience is teaching me never to go beyond 2x2 in future! I imagine that dealing with 25 panes introduces all sorts of additional complications... not least are which are file sizes, especially using an 11000?

Cheers Andy, yes the file sizes are huge. 22 Megs for a FIT, and I had to recently upgrade the laptop to be able to even use PS with the files. There is a 4 Gig limit on PS so I found that the 29layers would not save the panes. PS would flatten the image to save space. Very annoying when you're stitching the object. With the huge FOV, there are a lot of distortions the more panes you add. Some rotation from the polar alignment plays a part, and also I think that the registration of each pane gets more and more difficult. Some stars start to get elongated, or squashed a bit. I didn't take any of the panes while the moon was out and I was careful with the flats to avoid gradients, but there are some there due to the differences in shooting over multiple nights. Still DBE in PI is a massive help, that and the colour sampler in PS, and lots of patience. Give bigger mosaics a try again, its worth the effort.

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... yes the file sizes are huge. 22 Megs for a FIT

Wow... A bit of a difference to my lowly 1.44Mb! Sadly I'm unable to use DBE in PI - I dithered over buying it for 2 years or more and when I finally decided to bite the bullet... I found Pleiades don't supply or support 32 bit anymore :sad:. It would have come in VERY useful I'm sure with the OIII in particular - I'll have to save my pennies... or hope work buys me a new laptop sometime soon :rolleyes:.

It's also interesting to hear about the curvature you've mentioned - I think this is something Martin also came across with his recent huge mosaic... Although I know not the "right" reason for taking mosaics, they are very forgiving when viewed at 50% or less, which even for my 4x3 with the 314L+ is still 40"x40" - I dread to think how big yours would be at 100%... Do you have a wall big enough?!

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That has to be one of the most staggering images I've seem. This probably sounds really odd, but, to me, it conveys a real (and slightly dizzying) sense of the sheer enormity of space. Absolutely amazing Tom

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Wow... A bit of a difference to my lowly 1.44Mb! Sadly I'm unable to use DBE in PI - I dithered over buying it for 2 years or more and when I finally decided to bite the bullet... I found Pleiades don't supply or support 32 bit anymore :sad:. It would have come in VERY useful I'm sure with the OIII in particular - I'll have to save my pennies... or hope work buys me a new laptop sometime soon :rolleyes:.

It's also interesting to hear about the curvature you've mentioned - I think this is something Martin also came across with his recent huge mosaic... Although I know not the "right" reason for taking mosaics, they are very forgiving when viewed at 50% or less, which even for my 4x3 with the 314L+ is still 40"x40" - I dread to think how big yours would be at 100%... Do you have a wall big enough?!

I was chatting to Martin about that earlier, and we didn't have a real answer but some theories on it. I'm surprised that PI isn't in 32 bit anymore. A lot of the tools do need 64 bit to work properly, you get memory errors otherwise. 4x3 for the 314L is very big, nice job. For me the problem is finding a printer big enough not a wall :grin: Thanks for the comments also Mark and Steve. I'll try and keep these mosaics coming. Fingers crossed.
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