14 replies to this topic

[fizicksteacher]

I am very fortunate to live in the path of totality for the upcoming eclipse. I am using my rig to project an image of the Sun on a screen leading up to totality.  I am leaning towards turning the projector off during totality so people actually look at the eclipse instead of a picture of an eclipse but that is a different topic.

 

Anyway while testing my setup with a few of my astronomy students I got comments about isn't the Sun yellow? Now with my students I have the time to explain the how filters work, blackbody spectra etc. but for the general public I would much rather side step that and present the partial portion of the eclipse in a false color yellow since my solar film leaves me with a white light image even with the color camera, actually it is greenish in live mode due to the whole RGGB pixel thing.  Anyway using Sharpcap I can just adjust the color curves while live stacking to produce an "acceptable" color.  This is fine for a normal day, but during the eclipse the live stacking fails due to the motion of the moon over the solar disk.

 

The point, does anyone know of a way to adjust the color balance in the live view mode or get live stacking to automatically start over after say 20 frames so as to avoid the motion blur from the movement of the moon?

 

As an alternate solution, I am more than willing to learn a new capture program if anyone knows of one that can produce a false color image in real time.  I looked at Firecapture but didn't see a solution there but I might have just missed it. On my old astroberry there was a program that would do it, but since I upgraded to the 64bit raspberry pi 5, I don't have access to the older 32bit programs.

 

Any help would be greatly appreciated!

[steveward53]

Personally I'd leave it natural and white , but if you must have a yellow disc why not just stick a yellow filter on the front of the camera ... ?

[fizicksteacher]

The thought had crossed my mind, but ultimately I am hoping for a software solution since I currently don't have a yellow filter, not really a big deal since they are inexpensive. The big issue is I would have to eliminate my uv/ir filter in favor as my filter drawer won't let me stack filters. Thanks for the suggestion as that is my fall back plan.

[fizicksteacher]

Last night I downloaded the latest version on Sharpcap. 4.1.1 and they have added a feature called planetary live stacking which appears to do both the auto refreshing of the stack and/ adjusting the color balance so I can remove the green and add yellow/orange as the situation dictates. I still need to test it with an actual camera but I would need clear skies which for the next few days looks like it won't happen. I would still love to hear any thoughts though.

[cnbilbo]

You don't mention the equipment being used, but the colour film (aka Gels) used to colour theatre/stage lighting comes in many different shades & withstand high temperatures. Simply place it over the dew shield. A little crude but effective & cheap
.

Steve

Edited by cnbilbo, 16 March 2024 - 01:07 PM.

[bmcclana]

I think if you use the planetary live stacking with a short stacking duration it would work…. So you just have to setup the color balance within the tool.

I’ve use it like this a couple times, seems to work quite well.

You could even save the Timelapse to playback later showing the motion of the moon relative to the sun.

[cnbilbo]

I am very fortunate to live in the path of totality for the upcoming eclipse. I am using my rig to project an image of the Sun on a screen leading up to totality.  I am leaning towards turning the projector off during totality so people actually look at the eclipse instead of a picture of an eclipse but that is a different topic.
 
Anyway while testing my setup with a few of my astronomy students I got comments about isn't the Sun yellow? Now with my students I have the time to explain the how filters work, blackbody spectra etc. but for the general public I would much rather side step that and present the partial portion of the eclipse in a false color yellow since my solar film leaves me with a white light image even with the color camera, actually it is greenish in live mode due to the whole RGGB pixel thing.  Anyway using Sharpcap I can just adjust the color curves while live stacking to produce an "acceptable" color.  This is fine for a normal day, but during the eclipse the live stacking fails due to the motion of the moon over the solar disk.
 
The point, does anyone know of a way to adjust the color balance in the live view mode or get live stacking to automatically start over after say 20 frames so as to avoid the motion blur from the movement of the moon?
 
As an alternate solution, I am more than willing to learn a new capture program if anyone knows of one that can produce a false color image in real time.  I looked at Firecapture but didn't see a solution there but I might have just missed it. On my old astroberry there was a program that would do it, but since I upgraded to the 64bit raspberry pi 5, I don't have access to the older 32bit programs.
 
Any help would be greatly appreciated!

If you have a ZWO Camera skip my last answer.
Download ASI Studio. Click Planetary Imaging, Then select ASI Cap. At the bottom you will find a "Sun Colour" box. Tick the box and everything turns to gold.
I've just tested it on one of my cams and it works live.





Steve

Edited by cnbilbo, 16 March 2024 - 02:41 PM.

[fizicksteacher]

Sorry I am using Altair 183C zwo filter drawer system on a Williams Optics Zenithstar 73. I can talk to the theater folks I am sure they have gels I can use. Can't wait to try the planetary stacking. I will post back once I can test, thanks!

[Borodog]

SharpCap specifically includes solar colorization in the live planetary/lunar/solar stacking & enhancement tool.

[fizicksteacher]

SharpCap specifically includes solar colorization in the live planetary/lunar/solar stacking & enhancement tool.

I will definitely dig down into this new feature.  Thanks, for the pointer.

[fizicksteacher]

So after playing some more.  Couple of points. Solar Colorization feature in sharp cap 4.1 is only for Black and White Cameras.  I can however use the color adjustment on the timelapse feature "correct" the white light image.  Timelapse gives the most control over stack size as I can set the stack to 1 frame and then refresh.  Without on the Planetary/Solar Live stacking the stack has to have a minimum of 16 frames before refresh.  Which at max resolution I am getting about 2 fps so the stack only refreshes every 8 seconds even though my exposure time is in the ms range.  The active wavelet adjustment to the stack is a nice feature. I am going to work on reducing the image resolution to help with the low fps. Any other thoughts on increasing the fps.  I am using a usb3 connection, but the cord is on the longish side at 3.5m so I am reducing that length as much as I can and not have problems with placement.

 

Forgive the lemon yellow sun, I was in a rush a just playing with the sliders.  The green sun is what comes through live using my Altair 183c. 

 

 

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[cnbilbo]

So after playing some more.  Couple of points. Solar Colorization feature in sharp cap 4.1 is only for Black and White Cameras. 
Forgive the lemon yellow sun, I was in a rush a just playing with the sliders.  The green sun is what comes through live using my Altair 183c.

Hope this is not too late in the day for you but my kit is miles away.

Checked the colour cam with Sharpcap today. Selecting Mono 8 in the Colour Space drop down will enable the sun colourization in the FX dropdown. Hopefully this will sort things for you.



Have fun

Steve

[fizicksteacher]

That is brilliant, thank you!  Can't sleep too excited!!! 

[cnbilbo]

That is brilliant, thank you!  Can't sleep too excited!!! 

Wish I was there with you, Unfortunately my concord's parked up. The change in temp & the silence is quite dramatic. You can imagine the effect it would have on people in ancient times. Hopefully I'll get to see the next one in Spain in a couple of years.

Take a bit of time on the focusing, When taking snaps in sharpcap I think the colour will save if you select save as seen on screen.

Regardless have fabulous day

all the best from a dismal, soggy, UK

Steve

[fizicksteacher]

I was talking to one of my administrators about just that.  After the experience, I can say that during totality the level of darkness was enough to send a chill thinking of what it would have been like to have two armies stop fighting, return to their camps and decide to have peace instead of chancing the omen that a total eclipse must have been.  Even with being clouded out, it exceeded my wildest expectations!