fast telescope? slow telescope?!

[SpaceMonkey777]

I'm looking at the SW 150dob, with f7.84.

Is this considered fast or slow and what does this mean to me??

thanks for the help!

Jon:iamwithstupid:

[John]

For a newtonian (a dob is a newtonian on a simple mount) F/7.84 is quite slow. It means that the maximum field of view attainable will be narrower than a faster scope but that you will not need really short focal length eyepieces to achieve high magnification. A slow newtonian is also more forgiving of low cost eyepieces and is easier to collimate and keep collimated.

Slow scopes are popular for viewing the planets, the moon and binary stars. Faster scopes are popular with those that like wider fields of view to take in large deep sky objects.

[Capricorn]

The f/number relates to photography, on the assumption that you are using it for visual then don't worry overly about it.

There are characteristics relating to fast/slow scopes and if it is for visual then the slower one are possibly better.

Slow scopes being a longer focal length tend to be less critical of eyepieces, they need collimating less and with the same eyepiece you get a biit more magnification.