Telescope lens

[flossyplops]

Hi my son got a Meade ETX 80 for christmas, it had two lenses with it 26mm and 9.7mm, would anyone be able to recommend any upgrades from them? is it worth upgrading?
Thanks Heidi

 

[hollis_f]

Hi my son got a Meade ETX 80 for christmas, it had two lenses with it 26mm and 9.7mm, would anyone be able to recommend any upgrades from them? is it worth upgrading?
Thanks Heidi

You'll probably get a lot more answers in an astronomy forum. It's been several years since I had an ETX but, from memory, the 26mm was a pretty good eyepiece (not lens) and 9.7mm is about as small as you'd want to go on such a small scope.

 

[Mark_C]

Yeah 26mm is probably as much as you want to go for an 80mm scope. The smaller mm eyepiece you go the higher the magnification you can get but at the cost of resolution. This is why a lot of astronomers use larger scopes as they collect more photons. If you've got the room, I'd advise to eventually get a dobsonian, they're great for visual oberserving, very easy to use and have fantastic light collecting abilities.

 

[Dune]

It all depends on the air quality on that specific night. Some nights you can use a much high mag possel and get great views other nights your back to lower mags. I would say that one of the best things to get is a moon filter, on bright nights it can be painful through a scope.

Mark c is right over scope size, the bigger the better but the 80 is a good starter / travel scope. Newtonians get a bit bulky and need careful and regular cleaning, where as the smit-cas type you have is a lot easier. I built a 30" newt some years back I had to stand on top of a step ladder to get to the eye peice. What was good was that you could see colour in orion.

Another thing I would recomend is using periperal vision. You may not realise but the center of the eye has no receptors as thats where your optic nerve attaches. So if you look through the corner of your eye and train yourself to look through your scope like that you will pick up more detail.

 

[Cuchulainn]

Another thing I would recomend is using periperal vision. You may not realise but the center of the eye has no receptors as thats where your optic nerve attaches. So if you look through the corner of your eye and train yourself to look through your scope like that you will pick up more detail.

Not quite! The optic nerve is off centre, but you are right that there are no receptors around the nerve attachment. The centre of the eye actually has the highest density of receptors. The reason that using your peripheral vision is more effective is that in the centre of your vision you have none of the dim-light sensitive receptors, only the ones that respond to bright light and colour. So by using the edge of your vision you will have the equivalent of a lower resolution, but higher iso sensor!

 

[arad85]

The technique of using the periphery is called averted vision. For more details see: http://en.wikipedia.org/wiki/Averted_vision

If he is interested in astronomy, I'd join stargazerslounge (just google it). Best online astronomy community I found. You might find, as others have suggested, getting a bigger aperture is more rewarding than changing eyepieces.

 

[Splog]

The ETX80 is a good value all rounder and I'd say let your son get used to it using it more and I doubt changing it will help much, considering he's only had it a few weeks!

If you wish to add to the package? then I suggest an eyepiece of around 15mm, also a barlow and focal reducer, this will give a far better range of viewing options and allow him to see much more.