APT questions from total newbie

[kirkster501]

Hello guys,

Got my camera - canon 1100d hooked up to APT and my ED80 scope and checking into it all with dummy set-ups in the living room but have a few questions and would really appreciate your input on:

1. No serial cable required between camera and PC? I think it can all be done through the USB cable but would appreciate confirmation? Certainly the dummy plans I have created *seem* to work....

2. I don't understand the focus tool.... How can it focus without attaching to the telescope focuser in some way? Since the camera is at prime focus of the ED80 the only way to get focus is by the scopes own focuser right? So how do I use the tool to help get focused? And when focus is achieved on a star or something, is everything from then on "in focus" until the focus is disturbed?

3. it says mirror flip up is automatic with the Digik4? Not sure I understand this. I get ye reasons for mirror flip up per-se but why is this auto with the later cameras and why should I care?

4. connect to scope option. Why would i want this software to connect to the scope? Surely there must be reasons for this that my newbie brain does not yet understand...

Thanks, Steve

[JamesF]

WIth my 450D I only needed a USB connection, so I'd assume your 1100D should be the same. I have a nagging feeling that the serial connection is for older cameras that couldn't have the shutter operated over USB.

I think the focus tool is to allow you to get some sort of measurement of how well focused an image is, not to focus for you.

James

[kirkster501]

Ok thanks James for answering all my questions ! I am totally new to this and don't know anyone in my neighborhood to ask these questions. A little bit of a pointer and I can suss it out for myself thanks to you and others for the pointers !

[RikM]

No need for a serial cable with the 1100D.

There are a couple of focus tools. The FWHM box can be moved around the preview screen and gives an indication of how tight the focus is on the star in the box. The smaller the number, the better the focus. There is also a lens focus tool, which you can use to drive the autofocus motors when shooting with a camera and lens rather than a scope at prime focus. You focus using the scope focuser as you said.

No Idea about mirror flip up, never noticed that before.

The 'connect to scope' is so you can drive the scope around from the PC instead of using the handset...I think...again I don't use this feature. You would need to connect the mount directly to the PC for this though.

[Yoddha]

Hi Steve,

Here are more answers (I'm the author of APT)

1. Definitely you need only the USB cable with 1100D

2. I can't describe it better than Rik But with other words - you pickup a star in LiveView and using the scope focuser manually finds the lowest reading of FWHM. If you use lens then you can find the Autofocus feature quite handy. Everybody that tried that finds it very useful

3. 1100D doesn't support mirror locking. It is the only model what lacks this feature (it is very strange for me) In short mirror locking allows to flip the mirror some seconds before the start of the exposure. It helps to eliminate the influence of the vibrations caused by the mirror move. It is an issue only if your setup is on the limit. Usually it is not critical - especially with long exposures.

4. The telescope control is useful when you want to make small movements to frame an object or to make a GoTo without using the handset. Also it is needed for some features that I planned implement in future

[Gina]

I thought APT used the LiveView mode as an alternative to proper mirror lockup. Certainly when I use the Pause in APT with my 1100Ds the mirror goes up then the pause, then the exposure. At any rate, I have found no vibration problem with any astro images I've captured In fact I've found the 1100D excellent for AP