How not to image!

[Darth Takahashi]

Well I had a reasonable night on Monday this week and completely wasted it. Still, even the negative experiences are lessons to learn just not to be repeated.

Whilst in Japan a couple of months back I pickup a nice short tube sky90II. The reason that I'm telling you this is so the next part make sense!

For some strange reason I decided that my EM200 USD3 could just about manage my M250 + Sky90II and mounting material. It looked fantastic and I was just about able to reasonably balance everything with 20kg of weight all hanging on the end of the balance bar? There was a mismatch but I decided that it was small enough to press ahead.

After some web cam imaging on the moon with vlounge and a SPC900 I had a brain wave - more like a brain fart! I decided to do some wide field imaging with the Sky90II, all guided by the M250. Many of you are probably already laughing.

1. Guiding by Mewlon M250 and Atik 16C at 0.51 arcseconds / pixel

2. Imaging by Sky90II and 450D at 2.14 arcseconds / pixel

This was a disaster but not immediately! The EM200USD3 struggled on manfully for about 5 mins before giving up and lossing the guide star. So what did I do? I adjusted the setting in PHD and tried again:D. Guess what happened, it still lost the guide star...

Lessons learnt

1. An M250 + Sky90II are too much load for the EM200USD3, even though it looks good!

2. Guiding at 3000mm in typical Northen European weather conditions is impossible and a waste of time. The seeing is never good enough. Even if I'd had a bigger mount the seeing is the limiting factor!

3. Never use vlounge from Phillips for capture as it uses mov compressed format to record the video stream.

4. The one bonus from the night is that the computer control software from Canon for the 450D worked perfectly.

The only other plus point is that I have found the practical limited of my equipment. Other limits that I have suspected for a long time (Seeing) have now been confirmed.

Neil.

[Doc]

Looks like you have posted same message twice. I'm sure a mod will be along soon to delete one.

I thought a EM200 could handle that sort of wait. I must be wrong but as you say I bet it looked good.

[Darth Takahashi]

Sorry about posting twice, I don't know how that happened, maybe because I had to log back in to post?

Takahashi states 15kg for imaging and 18kg max. for the EM200USD3. I have pushed it to just under 19/20kg and still managed to imaged with it. The problem was that the M250 = 15kg + Sky90II 3kg + Tube rings 3kg + BT Technologies mounting plate 2kg etc...

In the end when I worked it all out excluding camera's, I had around 23kg load and at 3000mm native focal length for the M250 was just too much.

But it did look good. Even my wife commented on it:eek: Still not sure that that's a good thing!

Neil.

[barkis]

This must have been a bit of a bombshell for you Neil, this way of life is always throwing us curves, but I'm sure you could have done without this one. As you said though lessons learned.

Ron.