by mickb » 01 Jul 2020, 5:31 am
Mate you probably already know, but with eyepieces sometimes less is more. When working out magnification and you take the focal length of the telescope which will be a number provided in millimitres , probably 1200-1500 in your scopes case and then divide it by the mm of the eyepeice( which is printed on it), the magification can end up unworkable or too high. I tried plugging 3mm eyepieces into my scope with its 1200mm focal length expecting to get amazing views of the resulting 400x but the reality was the atmopheric conditions and the light gathering capabilities of the scope were not going to allow that sort of resolution. I found unless I wanted to look at awesome blurry blobs about half that magnification was more workable here in the tropics most nights, and I often enjoyed using a lot less.
Id say with a bit scope like yours you would not need the barlow to double power to get max, using my example above using a 4, 6 or 8mm eyepiece I would get magnification from 300, 200, 150x which took me to the limits of the scope. Using a barlow and the 4mm would increase it to 600x which was beyond the usable limits of its light gathering, everyting became 'highly magnified blurry blobs". Where a barlow is useful is more when you have 'gaps' in you eyepiece collection. For example you might have bought a 10mm, and 24mm. The barlow in doubling power allows you to halve those figures( which double magnification) so its like you now have an extra 5mm, and 12mm to play with by adding the barlow. Its more about flexibility than chasing the biggest magnification