Lodestar Live - December Update

[Paul81]

Hi All!

Been a bit quiet recently as I have been super busy off the pitch as it were. Anyway, I decided to create an SGL blog to chart the development of Lodestar Live rather the lots of posts on the group. I aim to keep the blog up to date as development progresses.

http://stargazerslounge.com/blog/1349/entry-1549-start-of-the-blog/

The first entry has details of recent efforts!

Paul

[Carl Reade]

Hi Paul can you not just do a 20 second near live loop with the camera? Or does it need what you doing software wise. Im not sure how these work TBH. 

[allcart]

I think the Lodestar is only a one shot camera, so can only display a single frame at a time, unlike video. I haven't used one either, but I don't think there is any software yet that will allow stacking on the fly. I'm sure thats what Paul is trying to develop. It would be really cool if he could manage this. 

[Paul81]

Hi folks!

You are correct, the Lodestar does not output video like a Watec or Mallincam, it takes single exposures of (in theory) unlimited duration. The application I am writing performs stacking and dark frame subtraction on the fly, and also allows you to adjust the image display parameters (the Lodestar is a 16-bit camera, hence you need to scale this to 8-bit for display) on the fly. There is software out there to do this kind of thing, mostly in different packages, but nothing (as far as I could tell) integrated into a single easy application, and certainly not for mac (my app is portable to windows, mac and linux). Basically, I want to turn the lodestar into a video style camera that it easy and enjoyable to use for live view astronomy.

Currently (a few issues aside) the app performs capture, dark frame subtraction, focus assistance, and image export. As for the stacking, I have developed the algorithms in matlab but have yet to port them to C++ for integration into the software. I am trying to sort out some lose ends before starting that (and have also had a few requests to support the colour version of the lodestar).

[DoctorD]

Hi

DSS Live can handle stacking on the fly but you also need a capture program to handle the continuous capture - as Paul says, you can use the lodestar for near real time viewing but it's not straight forward.

Using the basic lodestar software, you need to manually capture, convert from RAW to colour (if you have a colour camera) then adjust the levels to see the final image. All just a few mouse clicks - takes only a few seconds.

You can set the Lodestar software into continuous capture mode and apply automatic level adjustment but manual offers more control.

Paul's Lodestar live will offer you this flexibility along with automatic control.

I cannot wait for Christmas - MrsD says Santa might be bringing a Lodestar-C

Clear skies

Paul

[allcart]

Well if Paul can pull this off and make it compatible with a colour Lodestar running through windows, I will buy him a beer. I would probably get a Lodestar C as well. This would make the lodestar a very useful cam for live viewing.

[Dragon Man]

I applaude people like you Paul, for attempting to advance Video Astronomy to include even more cameras and software.

Whether people belive it or not, agree with it or not, or hate the idea or not, Video Astronomy is the way of the very near future for many people as the night skies vanish to light pollution for Visual and Astrophotography folk.

[Paul81]

Thank you all for the kind comments! I certainly would never refuse the offer of a beer! lol!

I agree, I think video astronomy is a great tool to go alongside visual observation - this is one of the reasons why I wanted something which was simple to use (like an eyepiece..) so as not to take away the experience of seeing things as near live as possible. Even in dark skies, the introduction of a camera taking short (60 secs or less) exposures will turn my 10" onto a telescope many times the size. For most of us, we have to contend with light pollution and this is where video really helps too.

My ultimate plan is to visually observe with the VX10, and run a side set-up (perhaps an RC8 with 0.5 reducer) with the Lodestar showing a detailed view.

Hmm.. sounds like Lodestar-C support is a very popular idea! I'll get thinking on my way forward to get colour in. I might have to have a scout around existing software and pick some peoples brains on how level adjustments are handled in colour from a user perspective. In LodestarLive as current (monochrome), you set the black (low) and white (high) level and it scales to 8-bit in that range using linear scaling (hyperbolic sine and logarithmic coming soon...). So would you set these levels independently for R, G and B, or as one setting for all colour components? I assume as well as gamma, brightness, and contrast some sort of colour balance / enhancement would be useful too to bring out some of the faint details.

[nytecam]

Hi All!

Been a bit quiet recently as I have been super busy off the pitch as it were. Anyway, I decided to create an SGL blog to chart the development of Lodestar Live rather the lots of posts on the group. I aim to keep the blog up to date as development progresses.

http://stargazerslounge.com/blog/1349/entry-1549-start-of-the-blog/

The first entry has details of recent efforts!  Paul

Hi Paul - glad you're making progress with the s/ware -  the Lodestar has lots of potential in the brief exposure field.  Well I would say that  Been using it successfully for 3yrs and the Lodestar-M for 2yrs prior to that via images on SGL and CN Fora.  Suggest you download both M and C s/ware from Starlight Xpress' site - they're helpful with codec.  What effect does 8-bit make to image quality against native 16-bit?  Lodestar-C colour is 8-bit per R+G+B channel.

Contrary to some comments here the colour image [via Lodestar-C s/ware] can be auto generated and in a continuous exposure loop and autosaved as files in FITS format, if desired, with auto date/time/exp stamped.  I choose to save raw images prior to colour conversion as the 'mono' file size is 1/3rd that of the colour image.  Colour saves would soon fill the HD!   Raws are the best saves - to my knowledge video has no raw files - all are auto processed and there's no going back to correct artefacts.

Good luck with the project - if you need any sample raws to play with let me know

[allcart]

Glad you're onboard with this project Maurice. Your experience with the Lodestars could be very helpful.

[DoctorD]

Hi Maurice

My apologies - I did not realise that you could auto generate the colour images in FIT format - looking at the Lodestar-C software without the camera I thought this was only a manual option. I'll be able to test it for myself soon!

Lodestar Live looks like it will be a very useful addition to the VA world.

CS

Paul

[Paul81]

Hi Maurice,

The raw bayer encoded data from the Lodestar-C will be 16-bit, so when it is converted to RGB, you will still get 16-bit RGB pixels as opposed to 8-bit - that is certainly the route I will be taking anyway! 16-bit offers a greater dynamic range, so you can capture both darker and lighter parts of objects in one exposure. Also the scaling of the image back to 8-bit (for display) allows teasing out of different details (this is actually in my opinion a great advantage the lodestar has over conventional video cameras for this type of work).

Based on some reading online, and going through Nik Szymanek's tutorials in AN, I am going to perform dark frame subtraction in the raw bayer encoded image space. This should mean hot pixels do not effect the colour of the surrounding pixels when converted to RGB.

After this, the raw image with be converted to RGB (I have done this many times in video processing systems - many different algorithms to suit different types of images), and processed from there. I think I am going to provide controls to alter the levels as a global setting (i.e. all colour channels at once) - this will work like the current mono version, but also have controls so each colour channel can be modified in brightness and contrast, thus effectively allowing re-balancing of the colours (often blue is the weakest channel in astro imaging so often needs a boost to get a natural looking image).

If I can grab some raw FITS files from your Lodestar that would really help get some of this prototyped - both light frames and a dark frame or two if that isn't too cheeky? I'll PM you my email details!

[nytecam]

Hi Paul - your seem to have all the problems under control !  

An error on my part in earlier post.  Been checking and whilst, under Lodestar-C s/ware, you can autosave to FITS and auto-colour-convert, you can't do both together eg save a colour converted images as a FITS! Also I believe there is no "FITS+colour format" - FITS is mono only unless things have changed recently. 

It probably doesn't matter for your s/ware but I can't do a colour FITS - only a generic SX colour file that you won't[?] be able to read 

[Paul81]

Hehe.. I am sure there will be some unexpected problems - there always are! Luckily I develop image processing systems in the professional life, so a lot of this stuff is known territory to some extent.

Can the software you are using save a raw bayer encoded image from you Lodestar-C to FITS in format (so basically mono 16-bit per pixel)? If so that is exactly the type of data I need to work with, as basically it is the raw dump from the camera CCD. I can feed that into the image processing algorithms for development and testing.

[budman1961]

I guess I cant understand why a live preview screen from the lodestar cannot be captured live, and broadcast live on google plus or nightskiesnetwork?  Is there something going on behind the scenes that would prohibit this from happening?

I'm kind of stumped on this camera.  Maurice presents reasonable images with his camera, I just cant figure out why a live broadcast seems to be undoable or unreasonable?

Andy

[nytecam]

I guess I cant understand why a live preview screen from the lodestar cannot be captured live, and broadcast live on google plus or nightskiesnetwork?  Is there something going on behind the scenes that would prohibit this from happening?

I'm kind of stumped on this camera.  Maurice presents reasonable images with his camera, I just cant figure out why a live broadcast seems to be undoable or unreasonable?Andy

Perhaps that's the reason for this thread!? Must up my 'reasonable' to ' better sometime - lol :-)

[Paul81]

I guess I cant understand why a live preview screen from the lodestar cannot be captured live, and broadcast live on google plus or nightskiesnetwork?  Is there something going on behind the scenes that would prohibit this from happening?

I'm kind of stumped on this camera.  Maurice presents reasonable images with his camera, I just cant figure out why a live broadcast seems to be undoable or unreasonable?

Andy

This is definitely do-able, it is just a question of the right software being available. A live broadcast via the web services mentioned is not currently on my roadmap at the moment though.

[allcart]

Don't worry Paul. If you can get the Lodestar to act like a video cam and give us the features you mentioned earlier, we can do the rest.