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First Light with Lodestar X2C and LLive


Dom543

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Hi All,

Yesterday I managed to get my first properly color balanced shots out of my new Lodestar X2C with LLive v.0.10. Thank you HiloDon for the advice. Here is the best I could get out of M27.

post-26379-0-57343500-1410811067.png

The 60 sec integration seems excessive but was necessary under the September skies of Seattle. The sky here was clear but the air was full of fine moisture and not transparent. One could barely see the bright alignment stars that the CGEM mount uses. And M27 was not visible in the eyepiece of my 10" Meade OTA. I had to center it in the field using the nearby stars and averted vision.

This was, actually, my second try with the new camera. The day before I got images straight from the Beatles song Strawberry Skies... This time I nudged the histogram spikes of the three colour channels to overlap using the brightness and contrast sliders. I don't exactly know what gamma goes but this image with gamma=2 looked better than with the default gamma=1.

My #1 desire would be to increase color saturation. If anyone knows a trick how to achieve that, I would really appreciate it. I have not tried those filters in LL. Could they be useful for this purpose?

My #2 wish would be to have rolling sum-stacking in LL. So that one could set the maximum  number frames and always the most recent this many frames would be summed. The registered stacking works very well in LL. In fact, better than the tracking of my mount. Fixed-number-of-frames sum-stacking would allow to limit single exposures to 30 sec, or whatever the tracking of the mount allows and synthesize the longer exposures through sum-stacking.

Anyway, big thank you to Paul for LodestarLive and similarly big thank you to SX for this very fast and sensitive modern camera.

Cheers!

--Dom  

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Hi Dom!

I'm just a bit north of you in Nanaimo, BC.  I'm impressed that you were able to get much if you are in Seattle!

I am also just starting out the Lodestar X2C/LL, and found as well that the colours were not as saturated as I 

might have expected.  HiloDon posted some suggestions in another thread, but it sounds like more colour 

related improvements are in the works for LL, which will be very nice!  At this point, I'm still just "fiddling" 

with settings trying to get something which passes the eyeball test as "reasonable", though I resorted to 

some very basic iPhoto (Mac) colour correction to remove some of the magenta cast I was seeing.

I think the filters (3x3?  5x5?) in LL are for smoothing rather than colour correction - if you mean the ones I'm 

thinking of.

Cheers, 

Greg A

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Dom and Greg,

In case you missed it, here's a link to the thread where some of the issues regarding the color problems with the Lodestar X2C and LL were discussed. The X2C is very new so I think there will be a lot of experimenting before it's perfected. There's some helpful responses by Paul in the thread.

http://stargazerslounge.com/topic/223311-first-light-lodestar-cx2/

I'm going to try more fiddling with the controls in LL to determine how they can improve saturation. I'll post the results here.

Don

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Hi Greg,

I have cousins in Victoria BC and nephews and nieces in Port Hardy, Port McNeil, Campbell River and other forestry towns on the Northern part of Vancouver Island. I bought my CGEM from a guy in Nanaimo. He turned solar...

The magenta tint is due to the fact that the red histogram spikes are to the right of the blue and green ones. You can move the histograms of the individual channels by first selecting their respective radio buttons on the bottom of the page (with NO checkmark in the "Change all channels" box). Then increasing "Brightness" moves the spike of the selected channel to the right and increasing "Contrast" moves the spike to the left. Doing this carefully, one can nudge the spikes to overlap exactly. That yields a neutral color balance.

Also, you need to move the "Black level" slider up to as close to the beginning of the histograms as possible. And the "White level" slider down as far as you can go without getting too bright of a background. In my case, the space between the two sliders is approximately 20% of the total available dynamic range.

I assume that your air is just as moisture rich as ours here. But you probably have much less light pollution. I have a straight view of downtown Seattle about 2-3 miles away across Lake Union. I see the city lights both directly and also reflected over the water...

Those are the filters I meant. I don't know what they are for.

Enjoy the nice clear nights, while they last! 

Cheers!

--Dom

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Dom & Don,

Thanks!  I read through the thread, and it appears that people have things well in hand.

I'll play around with the histograms more carefully on my next outing, Dom, and see what 

I can do.  There seemed a lot of "magenta" tint, but to varying degrees depending on what 

part of the sky I was looking at.  I wonder if it was at least partially a result of skyglow and 

the sensitivity of the X2C (more sensitive in the red end of the spectrum?)   It will be interesting 

to test this out, and see what Paul ends up doing to tweak the colour adjustments in the next 

version of LL.

As to the weather and moisture... yep, pretty similar to Seattle, but yes, thankfully a bit less 

light pollution to deal with (though Vancouver does a number on our low eastern skies....)

Cheers!

- Greg A

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Ok, guys, I did some tests with the LSX2c. I printed out a color bar chart and used my Nikon 50mm lens adapted to the LS. At 500ms exposure in a darkened room, I got a pretty good image. Color bar test 1 is what I got with no adjustment. I then went into the image control section and adjusted for balance by selecting green and adjusting the gamma slider to remove the magenta. I think you can use the brightness control as well. Not sure there's any difference there. The image was still a tinge red so I selected red and removed that as much as I could. No doubt finer controls would help. The result was color bar test 2. I then adjusted the white and black levels as Dom suggested above and the image brightened nicely shown in color bar test 3. I then went back to gamma, but selected modify all and moved the histogram to the left which intensified the colors, but threw the balance off again as seen in color bar test 4. The black and white levels need to be readjusted as well. I adjusted the balance again and stretched the histogram by using the contrast slider and readjustment of the white and black levels to get the final color bar test 5. The colors are definitely more saturated, but I'm not sure if the same will happen with outer space pictures. I should also add that I'm not sure I know what I am doing, but experimenting is fun. Isn't that how Madame Curie discovered radium?

post-36930-0-36602400-1410828816.jpg

post-36930-0-83880900-1410828860.jpg

post-36930-0-35206700-1410828885.jpg

post-36930-0-18302200-1410828915.jpg

post-36930-0-36464700-1410828949.jpg

Let me know what you think or if you have suggestions on further testing.

Don

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Hi All,

This is my second try. I used one of the subs that were stacked to get the image at the beginning of this thread. Then I did my best to mimic that Paul said v.011 will do. Here is the outcome.

post-26379-0-50529900-1411005292.png

Here are the steps that I took.

1. Loaded FIT file that was saved by LL during the observing session three days ago from the "Run" prompt with the command

<full path>\LodestarLive.exe -args -<full path>\<filename.fit>

2. Found the center of the dynamical range by moving the "Black Level" and "White Level" sliders to the point, where their position indicators on the right of the sliders displayed the same numbers.

3. Checked the "Modify all" box and moved all three histogram spikes to the center of the range by increasing gamma (to about 3.0). The red one ended up slightly on the right side of the center, the blue and green ones on the left side.

4. I fattened the histogram spikes by pushing up the contrast slider to its maximum position.

5. Moved the "Black Level" and "White Level" sliders to their original end positions and unchecked the "Modify All" checkbox.

6. Moved the three histogram spikes to a position, where their maxima overlapped exactly. This is done by checking the radio button of the respective colors and moving the "Brightness" slider up or down.

7. Moved the "Black Level" slider up to as close to the beginning of the now overlapping histogram spikes as possible. Moved the "White Level" slider down as far as I could without creating a whiteout spot inside of the nebula.

This is all. One difference between the image at the beginning of the thread and this "improved" one is that the recent image was created from a single FIT file and with no darks subtraction. The original image had a master dark made of 5 exposures subtracted and was the result of mean-stacking of 10 frames.

Cheers!

--Dom

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Thank you, Paul and All!

It cleared up for two nights last weekend. Below is my most recent attempt on M27. The LL settings were the same as described above. But this time it was live capture, not reloading an earlier captured FITS file. This way I could mean-stack 12 frames 60sec each. The result is a much smoother image. The alignment and stacking works very well in LL. I also used an IDAS LP2 filter. It helped to suppress many of the overwhelming background and foreground stars and to make the background darker. This way the nebula jumps out better from the background. Apart from the IDAS filter, this image is also filtered through the moisture-rich September atmosphere of Seattle. This time I managed to capture some of the cyan of the interior of the nebula. But nearly not as much as HiloDon from from under his Hawaii skies.

post-26379-0-71946400-1411613986.png

I also managed to see the Crescent and Bubble nebulas on my screen. But the shots are too faint and pale to be posted.

Clear Skies!

--Dom

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Very nice, Dom. Did you use some dark frames? The image looks very clear of hot pixels.

To get the Crescent and Bubble, you probably will need to use sum stacking. Here's my Bubble at 3x30s sum stacking with 30 second dark frames. You might need 4or more depending on the skies. This was right off the screen.

post-36930-0-14837000-1411620872.jpg

Don

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Thank you, Don! Your Bubble is very nice.

Yes, I used 5 darks for the last image. Darks are very easy to take with my flip mirror set up. No need to cover the scope. I take the darks, while the mirror is flipped to the eyepiece and I finding and centering the object. Here is a photo of my flip mirror with LSX2C <http://www.cloudynights.com/topic/144287-post-a-picture-of-your-assisted-visual-setup/page-14> #335 towards the bottom of page 14 or Post #6210685.

My earlier image, that was made from a single frame has quite a few hot pixels. The yellow and magenta ones are particularly noticeable. Comparing the earlier single frame image with the most recent dark subtracted one shows how well Paul's darks and stacking work.

--Dom

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