Various EPs and Powermate comparisons

[cgarry]

Looking at my young but quickly expanding EP collection I realised that there were some magnifications I could get in two different ways. So once the clouds cleared tonight I went out on a mission to compare the different options. So I spent a couple of hours constantly swapping EPs, which I am quite good at now.

Before I start I shall add a quick disclaimer that this is a beginners view since I have only had my scope a few weeks. Also the focal length of my 6SE scope is 1500mm so it is not very demanding on its EPs.

Tele Vue 15mm Plossl vs Revelation 15mm Plossl (from Revelation Photo-Visual Eyepiece kit)

Magnification: 100x

To start with I looked at Jupiter and its moons. At x100 this is quite small, but crystal clear through both EPs with nothing to choose between them to my eye. Next I moved over to the moon and my imediate reaction to both EPs was wow! After swapping between them a few times it became obvious that the edges of the view with the Revelation EP were not clear, while the Televue was clear right to the edge of the view.

All in all the Revelation eyepiece performed very well only failing to match the Televue when you got close to the edge of the view.

Tele Vue 8mm Plossl vs Revelation 20mm Plossl + Tele Vue Powermate (2.5x)

Magnification: 187.5x

I have to admit before trying this that I have loved the Tele Vue 8mm Plossl ever since I got it, so it is fair to say I started off a bit biased.

I started by looking at Jupiter through the Tele Vue EP. Unfortunately the seeing was terrible and I could not quite hit the sweet spot on the focus to get a good view. I could make out one belt but that was about it. Next I swapped over to the Powermate + Revelation EP combination and tried to focus. To my surprise I managed it. The seeing was still bad but this time I could make out the darker southern pole. I swapped back and forth a few times and soon realised that this was not just a fluke, the Powermate and Revelation EP combination performed better every time.

The other thing worth mentioning was eye relieve was so much nicer on the Powermate + Revelation EP combination. I had not had a problem in the past with the eye relief of the Tele Vue 8mm Plossl, but swapping between the two setups made it really obvious.

Celestron X-Cell 10mm vs Celestron E-Lux 25mm Plossl + Tele Vue Powermate (2.5x)

Magnification: 150x

I needed to swap between these two setups a lot of times before I could decide between them, both setups give excellent clear views. I seemed to find it harder to hit the sweet spot on the focus with the X-Cell and overall I preferred the E-Lux + Powermate combination, but it was close.

I should quickly mention that the Revelation Photo-Visual Eyepiece kit comes with its own 2x Barlow. I tried using this when I first got the kit and hated it. I could not see anything clearly though it and it has been sitting on a shelf ever since.

Conclusion

The big conclusion I came to was that the Tele Vue Powermate is awesome! As all the reviews I have read say, you really do not know it is there apart from the 2.5x magnification. I now see to reason to buy high power EPs, with their short eye relief and tiny little holes to view through when the Powermate allows much more comfortable EPs with longer focal lengths to do the same job.

[perrin6]

RE: the Revelation 20mm + 2.5 X powermate showing better detail on Jupe - Could this be because there was more glass in the former, dimming the view slightly making detail more stand out - Jupiter is rather bright ?

[cgarry]

RE: the Revelation 20mm + 2.5 X powermate showing better detail on Jupe - Could this be because there was more glass in the former, dimming the view slightly making detail more stand out - Jupiter is rather bright ?

That could easily be the reason. To be honest the seeing was not good enough to use 187x magnification so I am not sure how valid the result is. I want to try the test again when the conditions are better, plus try looking at a few more targets and check out how much of the field of view is usable.

Chris

[Kef9]

I have the 2" powermate and it works brilliantly with my ethos line.

It really does dissapear.

[Markstar]

very informative post from 'cgarry', cheers!

I am also quite new to astronomy and have been thinking of investing in a powermate...looking forward to receiving my new BST Explorers in a few days. Hopefully should improve my Celestron 127eq (stop laughing, lol!!!)