plate solving with AZ mount

[zoltrix]

hello

is the 2 or 3 star alignment of an AZ mount necessary before plate solving ?

[admin]

Hi,

yes, since if you have not done the 2/3 star alignment the mount may not report a position at all, or it may be a *long* way from where you are really pointing. You can use 'Plate solve only' from the tools menu without alignment, but it will take longer as it has to search the whole sky.

cheers,

Robin

[zoltrix]

thanks Robin

a couple of questions

# is plate solving in any case reliable even though it will take longer ?
# if the mount is fitted with encoders it should report its position (azimuth and elevation)

[admin]

Hi,

yes, plate solving should eventually give a result even if it has to search the whole sky (exception: PlateSolve2 is too slow - SharpCap will not attempt a whole sky search using it). You should get the same result, it will just take longer to get there than it would if you could tell the plate solving program 'look in this region only'.

With encoders, the mount will know the orientation of the telescope relative to the mount base, but there will still be some uncertainty if you move the tripod into position each night - a few degrees error perhaps due to slightly different alignment or tilt of the mount. Plate solving should cope with that though, even without a full sky search (SharpCap defaults to a radius of 15 degrees if it thinks it knows the current position of the telescope).

cheers,

Robin

[zoltrix]

thanks again Robin

good news...
actually I tried time ago but it did not work probably I was using platesolve2
however if you can key in also azimuth and altitude of your scope, I think that it would be of great help
it should be enough to orient the tripod
it is what it must be done with "north level alignment" method then to go manually close to target in a 15 degrees radius should not be that hard
on the other hands sometimes the 2 or 3 stars alignment can be an issue because of clouds and/or natural obstacles particulary for "balcony" people

[admin]

Hi,

also, PlateSolve2 is probably the least capable of the plate solving engines you can use in SharpCap - it works, but it is too slow to do a full sky search for instance.

The latest version of SharpCap 4.1 contains a new, built-in, plate solving engine that I have developed. This means that you no longer need an external plate solving tool as long as your field size is at least 0.5 degrees in each direction. Read more here : viewtopic.php?t=7122

cheers,

Robin