Live webcast - on-air

Hi Denis - I only have a DEC motor on the C8 and my polar alignment isn't good enough to keep the target centered for too long. So frequent trips out to the scope are the order of the day. Also, I don;t have the C8 connected to the laptop. But all this will change next week with the delivery of an AP1200GTO mount. I can then control the mount fully by remote PC. Far fewer trips to the bottom of the garden

The software will stack the image using a reference point that you specify (you draw a target box around the point). This does fine - until the target moves off the CCD... Then its back down the garden...


When you see the image jump on the webcast, what has happened there is I've started taking a new image. I've reset the software, got back onto the target and re-drawn the target box... The DSI keeps imaging until you tell it to stop. During a given image sequence, the target will not move on the composite image, but will move on each individual frame (how much depends on how good the tracking is).

The software to its credit, does what Registax does, but live...

Does this help?

Ask away if you have more questions!

We're onto deep sky now - somewhere in Ursa Major!

Cheers

Dave McD

Now I understand the process

I've googled your ref to the mount - AP1200GTO . The price ! :shock:

I can see, I'm playing with the big boys here

Some of the images of Ursa Major were very grainey, with diagonal striations in the grey. I expect the software does this. You are not adjusting contrast before uploading, i expect. With a bit more processing the image might get sharper ?

Or does the DSI software have a feature to auto adjust color mix/threshold levels etc ?
I see , at present, it's perfectly black and white and sharp. Maybe it's a feature you are turning on or off for effect ?


Denis

Dave,

Clarify for me ? The images are inverted . I had Starry Night open while you had Ursa up and tried to relate the starry night image to you pic.

Tricky

Denis

Hi Denis - to be honest, I've no idea where the scope is pointing in Ursa Major. The tracking is even worse now that I've just tripped over the tripod There's the polar alignment gone anyhow...

The DSI software lets you control a whole host of variables - exposure time, contrast, shadows, gain, offset, white point/black point and also how your images are processed to an extent. It also allows automatic substraction of pre-taken darks.

Striations are probably due to tracking - if you see a more grainy border, that is definately tracking. I try and adjust all these variables prior to starting the composite image process. But sometimes, you take 30 plus images in one composite only to find that it looks crap. Of copurse, the DSI can do all this automatically for you but the results tend to be mixed. Colour is particularly problematic and I am avoiding it for now.

The image does get sharper over time - but tracking is then the issue. You need to keep the target in the frame for this to work well. Hence the AP1200. And no, you don't want to know how much. The VAT man will be happy though... As will the shippers - at 100Kg of kit, they're getting a tidy cut :shock: Now, all I need is Celestron astrograph and a cloud remover...

Actually, the scope is dewing up now so I'll probably pack it in shortly. Dewheaters will have to wait....

All the best

Cheers

Dave McD

Hi Denis,
I watched the eclipse webcast on this link
www.live-eclipse.org/en/live.html.en

You would definitely have needed broadband to watch it.
I believe they have a number of short movies available for download now.

Regards,
Brian

Hi All
Some early photos of the Total Eclipse from 8th April are available here at the bottom of the page.

www.moonglow.net/eclipse/2005apr08/

Apparently the satellite communications onboard the cruise ships were not not up to transmitting live webcasts. I am sure that with all the technical eclipse experts on board these ships that they must have tried their best to transmit to all of us who could not make it. However it appears most of them gave up trying early on Thursday.

Regards,
Brian