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Orthoscopic Eyepieces


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It is birthday time and my girlfriend wants to buy me something for my telescope. I have a celestron 6se and use a 8mm baader hyperion for my highpower observing, however i never seem to be able to focus the image. I have read that orthoscopic eyepieces are the best option for planetary observation, would you say an orthoscopic is a good choice? Am i likely to have the same focussing issue if i go for something in the order of 5mm to 8mm?

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Just a little warning, if you like the viewing comfort and field of view of the Hyperion, you may find an ortho less than satisfying - their optical performance is excellent but, in the shorter focal lengths, the small eye lens, tight eye relief and relatively narrow field of view can be trying.

I've owned a couple of sets of orthos and ended up going back to eyepieces with more eye relief and a wider field of view eventually.

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I would presonally try the 12.5mm its lovely, on jupiter the image is not to small in my 6SE and the eye relief is very nice, i used it at the public observing night and even newbies found it comfortable enough to use even compared to hyperions

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Thanks for the info.

I do find my hyperion very comfortable to use but wonered if they perform as well at higher power as I have looked at the 8mm in their range ?

In slow scopes I reckon the Hyperions do extremely well - if there are any differences they will be barely noticeable at most and the viewing comfort that they deliver may well offset this.

Heres a little review I did a while back comparing the Hyperions to the excellent but more expensive Vixen LVW's:

Vixen - LVW Comparison Review

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I have two dobs at 1600mm focal length so very similar. I'd make a couple of observations as follows:

1) I found that the 9mm Baader Genuine Ortho I had hit the sweet spot most of the time and offered excellent sharp views. the 12.5mm offered even sharper views but a smaller image. both are wonderfully sharp and as long as you don't wear specs to observe and have a tracking mount then as far as I am concerned BGOs are the best planetary eye pieces you can buy at this focal length.

2) might be a mildly offensive question but I presume you are ensuring your scope is fully cool before observing? I have never owned one but I understand it can take a couple of hours at least for a 6" SCT to cool I suspect if taken from indoors to outside.

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Thanks for all the comments.

Yes i do allow plenty of time for my scope to cool down. I have to admit i had forgotten about eye relief. I am a little unsure about investing in another Hyperion as i haven't had fantastic results with my 8mm, although i do recognise that is more due to poor seeing it has effected my confidence in them. I have a 2" 40mm william optics eyepiece which i really like so maybe i should look for a 9 or 10mm WO.

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Thanks again,

Yeah I'm still in two minds but not in a rush to purchase.

Moonshane assume part (2) of your post was directed at Monkey_Coral ?

I do notice a difference in focusing if I don't let my scope cool down enough.

Cheers

Neil

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Thanks again,

Yeah I'm still in two minds but not in a rush to purchase.

Moonshane assume part (2) of your post was directed at Monkey_Coral ?

I do notice a difference in focusing if I don't let my scope cool down enough.

Cheers

Neil

hi Neil, sorry yes, the OP.

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would you say an orthoscopic is a good choice? Am i likely to have the same focussing issue if i go for something in the order of 5mm to 8mm?

BGO's for me are simply superb and I doubt I will ever see the day I get rid of mine. The tight eye lens on the short focal length EP's mean they won't float everyones boat but the views are unbeatable IMO.

The downside is they seem to eat up focus travel and I have experienced focusing problems with only one step up in focal length from 5mm to 6mm. Resolved with an extension tube but this would have to be considered if you are on a budget.

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BGO's for me are simply superb and I doubt I will ever see the day I get rid of mine. The tight eye lens on the short focal length EP's mean they won't float everyones boat but the views are unbeatable IMO.

yep been thinking for a while to invest in a bgo,,,,

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I find it shocking that anyone would sell them. They are cheap as chips used yet they offer some of the most defined images of planets I could ever ask for. I'm sure going up against similar designs the differences would be negligible but if your looking to start a new collection I would say you can't go far wrong unless you wear glasses. I'm guessing most may consider the 7mm on the limit of bearable regards comfort of use as the 6 & 5mm have very small port holes to the universe and unless your dedicated to the point of insanity then it may pay to try before you buy with the shorter focal lengths.

Again I will point out and other may agree that the down side of BGO's is they are very testing on your focuser's travel and again this is another good reason to TBYB.

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In slow scopes I reckon the Hyperions do extremely well - if there are any differences they will be barely noticeable at most and the viewing comfort that they deliver may well offset this.

Heres a little review I did a while back comparing the Hyperions to the excellent but more expensive Vixen LVW's:

Vixen - LVW Comparison Review

very nice review

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Regarding sharpness, contrast and overall image quality BGOs are superb. Got most of mine s/h for about half price too.

Compared to an Ethos they have a slight edge on the contrast. For instance, I can pick the GRS on Jupiter easier on them then the Ethos. They are not very confortable though.

I usually go with the Ethos for confort, but when a formation on the moon, or a subtle shade on the gas giants catches my eye, I put a BGO in to try and tease a bit more detail out of it.

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good advise already given on the ep option guys, as for focusing...it is a bit of a pain on Celestron sct scopes apart from the new Hd range which have mirror lock as do Meade with some of theirs.

I found it a tad annoying using my 6se but was happy enough just to see so many nice objects that I sort of put up with it, when I sold it and bought the cpc 925 I had no better luck with that so looked at a different type of focuser altogether, pushed the boat out and bought a Moonlite, need I say more?

Image shift is completely under control with it and I do like the smooth action and presice control sadly lacking from the built in focuser on the 925.

Would also say the longer you can leave an sct to cool down the better, on many occasions I have left mine out for a good couple of hours before using it, the views are certainly improved if you can resist using yours for that length of time.

A way to speed that cool down time up is to open up the rear end completely, just wrap a piece of cloth around the baffle and out an elastic band around it so nothing can get inside and allow the warm air to escape.

I do not use that method myself but have read it does work.

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