SingAstro

Hi, can anyone explain in more detail what is autoguider port? Is it mandatory for astrography (prime focus) etc?
Thanks in advance

Im not into imaging..but in layman terms:

When there's a main scope (with ccd camera or imaging train attached), u may notice there's a smaller scope (like a small refractor) mounted on top of the main telescope held in place by dual rings...this smaller scope acts as the Guidescope. This is to hold either the target itself (which the main scope is pointing at) or a nearby guide star at a "centered" position so that the tracking is accurate and images don't trail...accuracy is very critical for Deep sky (nebula, stars, etc.) imaging.

For bright objects like Moon , not so essential, so whether is mandatory or not..depends on the object you are shooting at the time..

hope this helps!

You either need a ST-4 autoguider port or your mount must be able to get autoguiding signal via ascom.

Mooey: (thumbs up)

autoguider port? nonsense!

With ProTrack you don't need no steekin' autoguider.

Seriously, to the OP:

autoguiding is needed if you want to take exposures longer than about 1 minute (unless your mount costs 5 digits).

basically you have a secondary telescope with a guide camera that watches a star. The star will wiggle back and forth due to errors in the gears of your mount. The computer connected to the guide camera will watch the wiggles and issue corrections to counteract the wiggles. The corrections are sent to the mount either via the mount's ST-4 port (you will need a GPUSB plugged into your computer) or via ASCOM, as MooEy mentioned. The most common way to drive a mount using ASCOM is via the mount's serial port. You would need a USB to serial converter, get an FTDI one.

only the high-end mounts have less need for autoguiding because they have inherently more precise gears. but even with better gears, the sidereal rate changes as the object moves through the sky (stars move fastest when overhead, and slowest close to the horizon) so even a good mount would need autoguiding. Unless you have mount modeling and variable-rate tracking, such as the ProTrack mentioned above. Note that ProTrack only works on Software Bisque mounts. Astro-Physics mounts are supposed to get similar mount modeling and long-exposure unguided capability with APCC Pro, which hasn't been released yet.

but the vast majority of us use auto-guiding.

On the topic of apcc, anyone tried out the s-chip yet?

~MooEy~

I have the S chip (bought it and installed it myself). But it doesn't really give me anything new because I don't have APCC.

It is supposed to improve crash protection, i.e. the mount will not auto-restart tracking when it loses and regains power. This is supposed to help robotic operation. But again I see no difference. I can pull the power, come back later, turn it back on, resume from park and continue from when I left off. But I understand you don't need the S chip for that.