Explore Scientific - Argon vs Nitrogen?

[rwilkey]

I have tested the 4.7mm and though it is not quite a Televue or Pentax it can be about a third of the price of one.

Good eyepieces,

Alan

Hi Alan, I have been thinking about the 4.7mm, but at the moment others suit my viewing preferences better (star clusters & nebs), but great to hear your views.

[alan potts]

Robin,

I would think you would be OK with the 4.7mm but this is more for Jupiter, Saturn, Venus and the Moon I would have thought, I used a 1000mm scope so the power would be the same but a fraction brighter in yours. I regualarly use a 4mm Radian in the same scope and it handles that well and even higher on good nights.  It is a very long time since I observed in England but I would have thought X212 was useable most nights. If you have not got much in the way of LP globulars will take this power too, some like M 15 & M 80 need it, though the latter is way past its best.

TS over in Germany have this 4.7mm at 119 Eu which is a very good price, if you read the review it was against the XW 5mm at a massive 369 Eu, this make the UK look cheap.

When you think the Meade S5000 4.7mm was 179 pounds if I recall correctly, though from memory I though mine was the tiniest bit better.

Alan

[baggywrinkle]

Either Argon or N2 would be fine, but do they state what dew point the gas is? Do they purge before sealing in order to remove moisture molecules which adhere to the surfaces.

That said it is a bit of a gimmick. Unless they purge and seal in a very dry environment then the moisture molecules would desorb off the surfaces and the effect would be lost. Plus the outer surface of the lens would still be exposed to cold air.

We used to purge periscopes after they had been serviced but that was with good reason, the skipper would throw a wobbly if he got misty views! Plus part of the scope was inside the pressure hull and the other exposed to cold seawater so there was a large change in temperature.

[rwilkey]

Robin,

I would think you would be OK with the 4.7mm but this is more for Jupiter, Saturn, Venus and the Moon I would have thought, I used a 1000mm scope so the power would be the same but a fraction brighter in yours. I regualarly use a 4mm Radian in the same scope and it handles that well and even higher on good nights.  It is a very long time since I observed in England but I would have thought X212 was useable most nights. If you have not got much in the way of LP globulars will take this power too, some like M 15 & M 80 need it, though the latter is way past its best.

TS over in Germany have this 4.7mm at 119 Eu which is a very good price, if you read the review it was against the XW 5mm at a massive 369 Eu, this make the UK look cheap.

When you think the Meade S5000 4.7mm was 179 pounds if I recall correctly, though from memory I though mine was the tiniest bit better.

Alan

Hi Alan, after looking at the TS website, I decided to go for the 4.7mm having whetted my own curiosity, and ended up buying it at Telescope House at £107, also a good price and next day timed delivery.  Great, I got it this morning and have tested it out in daylight, looks good, needed a lot of back focus for objects across the street (the view from my front window).  I look forward to using it at night time now, roll on clear skies!

[alan potts]

I will not say you could use some of my weather which I would normally as it is rain outside again, it's almost like being in England this year. Good luck with the 4.7, I think you will like it, I've still got the one I tested here so I may give it another outing if the clouds play ball.

Alan