BAADER HYPERION MODULAR SPECIFICATIONS

[bomberbaz]

I decided to make a spreadsheet of what I consider to be use able variations of the Hyperion eyepieces. I have got a F4.9 12" Dob now and wanted to check on the magnifications my EP's would produce.

Anyway this as ended up in me putting together a kind of review, not really based upon viewing experience (although I do mention it in one area) but on versatility.

I did this in-between clear skies, so it didn't take long

The top two lens are not Baader but I put them on anyway for my own purposes.

Below that the Hyperions are boxed with the top white one being the master size and the ones below the variations.

The 17mm basically cross over all the other variations so these are not on the spreadsheet, and the 17mm without the first set of lens in pink is more or less the standard for any without the first set of lens except the 21mm which I don't have.

While on the 17mm minus lens variation, I have used it in that mode a couple of times although not with the new Dob but the honest use able area when in that mode is in my opinion only about 70% at most. (I suspect this will be the same or even less when tried out live) Also i can't be sure of the FOV but my calculations bring it in at 79, I may be a little out but I used the field stop quoted of 30 to come to that and the TFOV.

I realise some of the smaller sizes also cross over almost but only really at around 8mm. The 9mm crossover is with a filter so its a diffferent EP altogether in that respect. So it boils down to what you are using on the night as to which one you end up modifying.

Also the filters quoted are Baader filters, Skywatcher filters are slightly thinner so the modular size of the EP will be slightly higher.

One thing I did find is the 10mm variations are very hard to find, even Baader themselves seem to miss it from their own literature which I found a little strange.

At first I found the changing around with the Fine tuning Rings a little fiddly but once you have done it a few times it is quite easy, even on a cold night. I now have 2 x 14mm FTR's as these just seem to get used more than the 28mm version. And of course 2 of them make a 28mm anyway.

Under 5mm takes magnification very high and the exit pupil is under 1mm, I don't think under 4mm would be use able at all. With a 28mm FTR you are up to 470 mag and exit pupil at 0.64mm,very unlikely to be used. Of course this is with my scope and so users of shorter focal length scopes will have different resulting figures for magnification, TFOV and exit pupil.

So what you do have is effectively 16 eyepieces for the cost of four and a few extras. The FTR's are under 50 pounds and the filters, well you need them whatever. I have a NDF, O-III and UHC-S (all Baader) at 2", these sit between the first set of lens and the main EP body as do the FTR's.

They state the EP's to be par-focal and by and large, they are right. Sure you need a little tweaking but nothing other than that.

The other two EP's are a Moonfish 30mm and a SWAN UWA 25mm. The only other bit of kit I have is a 1.25mm variable polarising filter which is a great bit of kit.

Again other users will have to work out their own figures for their own scopes but the modular sizes are standard.

In closing I know in reality I am not going to use all these variations, however it is nice know I have so many options. I will play around and come to my favourites and stick by them. However I shall print this off and laminate just as an aid until I find my preferred selections. Finally for what you pay and get, I reckon that the Baader Hyperion's are a hard act to follow.

Steve.

[John]

I think the Hyperions are thoughtfully designed and very flexible as your table suggests. It's just a shame that they show quite so much astigmatism when the focal ratio dips below F/7 or so.

[twotter]

I either don't recognise astigmatism when I see it, or else it doesn't bother me, because I use my Hyperions in both my F10 refractor and F6 dob and enjoy the views in both. With the fine tuning rings I could really get by with fewer eyepieces but where is the fun in that?