BGO 7mm & 9mm available

[faulksy]

Nice purchases Graham and Russell

I have the BGO 5mm and 6mm and a TV plossl 8mm as my "low glass" set. Very nice eyepieces

I'll be getting some of the Hutech / Kasai orthos in the next few days so expect a "shoot out" report including the Baader Classic's in due course

that will be good john, look foward to that

[Stargazer_00]

I've just done a first light on the moon and jupiter with the ES 6.7mm ES 4.7mm and BGO 6mm in both my 250px and 150p.

In short the BGO wins, on axis, for contrast and colour control. sharpness right on axis is a win for the BGO but the ESs perform very well on axis too, its quite close.

Jupiter (planets I guess)

For instance right now I am able to see clearly the GRS seperated from the main band its spinning in in all eyepieces. The BGO appears fractionally better right at the centre but I found it drops off both focus, contrast and sharpness massively from about 50% out and continues to the edge where it isnt good at all. Bang on axis in the dead centre 10% it's very good. So I just kept nudging it to keep it on this sweet spot.

I put in a 6.7 and a 4.7 and could resolve similar detail on axis. I find the ESs introduce an amount of false colour on bright objects which is a little off putting, but the wide field trades this off and I found that the ESs perform well across 50%-60% of the field where the majority of abberations are under control well enough not to be distracting.

Between BGO and ES I found the ESs more comfortable on Jupiter because they needed less nudging and the on axis performance between them was comparable enough. the ESs performed much better over a wider field of view so that was the win here for me.

This was all in the 10". So BGO 6mm 200x, 4.7mm 255x, 6.7mm 180x

Lunar

I found the BGO a hands down winner here. no contest.

I was using the hadley rile (rima hadley?) as my target. I was able to resolve this feature in all eyepieces on my 10" and it was difficult in the 150p for the ESs but would appear every few seconds and go again in them, and when in view be a little soft, but was nearly a constant sharp, well defined, contrasted feature in the BGO with a long continuous sinuous rile resolved perfectly well (again only on axis) even at the low mangification of 125x. The 4.7mm was 160x here and the 6.7mm - 111x

The wide views in the ESs makes the moon difficult to look at if you are trying to pick out specific features as the periphial vision is blinded in the glare. There is too much going into the visual cortex to be able to concentrate on the detail on axis. The BGO makes hunting specific features much easier as your eye is focused on the specific field of view. I again found that the view on axis was amazing but very quickly degraded around 45%-50% and then became just a blurry feature from there to field stop. The moon wasn't moving too fast even in the 10" at 200x so could quite easily keep the target in the centre 10% area with a little nudge every 10 seconds or so.

It just clouded over a bit so I came in, its reportedly going to be clear for a few hours tonight and will be proper dark soon. It was still quite light when I was doing this viewing.

This is obviously only a first light, first impression with less than an hour, which included swapping out eyepieces. Maybe 40 minutes of viewing time with the BGO only so far. I would need a lot more time with them to get to know them better. They aren't exact matches on magnification so it's not really a true test anyway, a lot of variables are not the same here so comparison is as much personal perference and opinion as any real grounded observed truths.

The eye relief on the BGO is about the same as the 4.7mm ES in terms of tightness but the BGO is somehow easier to cosy up to. It's much colder on the face though when it touches skin, the ES having a rubber guard the BGO being a lump of metal.

The wife even came out and snapped me at it!! You can see it's still quite light as well.

You can see just how comfortable a mey observing stool is with a dob.

[John]

Nice report Graham

I'm using BGO's and Pentax XW's on the moon tonight. Seeing is a bit unsteady but I'm picking out some great detail in the steadier moments. Silly hobby in a way - we spend all this time and dosh getting the very best eyepieces and scopes we can, get them cooled and collimated and then nature just occasionally gives us glimpses for a few seconds of that our gear can really do !.

You sort of live for those moments for a while when observing the moon or planets at high power though

[Stargazer_00]

Absolutely John. The seeing is variable tonight but for fleeting moments it really is snapping into absolutely perfect viewing. Going to go back out and break in the BGO on the moon some more The rest of the sky can rest tonight, the moon is my target.

[andrew63]

Good you had a chance to give them a spin. Surprised to here of the quality of view dropping that far out. I guess it's the coma in your mirror ? Mine is razor sharp to the field stop.

andrew

[russ.will]

I was wondering if the fact that two relatively fast reflectors might have a bearing on that.

Russell

Sent from my iPad using Tapatalk HD using chubby fingers. Sorry.

[John]

I've just checked out the view with my 6mm BGO on the Moon. I'm using my 12" F/5.3 dob and the view stays sharp to the field stop. I've just tracked some craterlets on the floor of Plato and they stayed crisply defined as they slid behind the field stop. F/5.3 is a bit different from F/4.7 though.

Just for a change I switched to my ES 20mm / 100 to look at the whole lunar disk against the blackness of space. What a beautiful object it is. The changes in surface texture and tone are really quite stunning at a lower power.

Comet Panstarrs is not looking too bad either, despite being rather low in the NE right now. Good night tonight and no wind - lovely

[Stargazer_00]

Interesting you should say about plato. I was just working down the terminator on my Lunar 100 list and the last target was plato craterlets which id never looked for before.

I haven't looked at a photograph yet to see how many there are but I could clearly see 2 and a linear feature like a rile running across the crater. I drew a quick sketh with a biro was that was all i had on me. (please excuse the quality as you dont have many options with a biro... ) so I could record what I was looking at. There was a patch of differing colour which I loosley sketched within the crater in which I think I might've just seen another craterlet but i couldnt be sure so didnt draw it.

Could only see the central craterlet in the ES 4.7, could see all 3 of the sketched features in the BGO. I'll have to look at why its loosing focus past 50% but it certainly is.

Again in the dob at 200x

[John]

Nice sketch Graham

[Qualia]

I actually loved the look of the Delos. So comfortable...

Guess what Mr. Posty delivered today after me selling a load of EPs and saving for about two months

[Stargazer_00]

[Dude_with_the_tube]

Very interesting report! I might be tempted by this.somehow i think our 10" require coma corrector to fully enjoy the views and quality of BGO.

thanks for the effort.appreciated Graham.

[John]

Very interesting report! I might be tempted by this.somehow i think our 10" require coma corrector to fully enjoy the views and quality of BGO.

thanks for the effort.appreciated Graham.

The coma corrector would benefit a wide or ultra wide more I reckon. The narrow field of the ortho should make coma less obvious.

[russ.will]

Good night tonight and no wind - lovely

I assume that this isn't a dietary reference?

Russell

[alan potts]

Very nice report Graham, I think John was right with the speed of you scope at F 4.7, I don't have anything as quick as that myself not that Delos would have any troubles. I have marked to calendar " on this day Graham said "I will run with them for a year " We will see, we will see. I am the man that said " what the hell do you need 82 degree eyepieces for " until I saw a 20mm Nagler and the same happened, smitten.

I think I am looking forward to my BGO's, when I get back Antares will be getting up earlier and I want to crack this this year.

Alan.

[Stargazer_00]

Never say never I guess

going to check my scopes collimation today. Didn't do them last night when I put them out so they might have been slighty off the sweet spots. I wouldn't have thought this was coma at all given the magnification it would've been utilising only a small central part of the mirror not the edge where coma is usually introduced at low magnification. which uses the whole mirror. This is much more like a collimation error or simply the eyepiece just doesn't like the scope. It's be good to get an honest report from someone with the same exact scope and eyepiece. Our maybe even have someone confirm what I'm seeing on mine.

I've plans to meet a board member in the near future so maybe can do that then

EDIT: I did a mock up of a photo of Plato at about the same moon phase as last night versus the sketch i did. The red circle is a match. the blue circle I saw as one but is actually two. the green area is where I saw a white line crossing the crater, barely visible in the photo though and the yellow circle was where I suspected there was another but couldn't say for sure. turns out it was one so I think that counts.

I now believe the real challenge here lies in visibly splitting the pair in the blue circle

[Stargazer_00]

Just having a think about the sharpness drop off. Could it be the way I observe that introduces the error? It would be hard to articulate this so I drew something to explain (in case it isnt obvious im quite visual - i always feel the need to draw things..)

In 1. This is standard obseving with eye square to exit pupil and head square to eye. looking at the central part of the field and observing edges only in periphial.

in 2. tracking an object across the field without moving head, the eye moves away from the exit pupil leaving some light not entering the eye.

in 3. head tilts around eye which remains central this allows you to look into the eyepiece at an angle but keeps the pupil central to the exit pupil light shaft. You need to move slightly closer so that you line of sight remains within the exit pupil light shaft.

I find 2 works if the object isn't tracked far out from centre but introduce kidney beans and blackout on 82 degrees so I use method 3 for UWAs.

I was using method 2 for the BGO as the field is tighter. Could this introduce out of focus, sharpness loss/blurring? Obviously when tracking an object in this way the on axis is not your focus so I couldn't say the quality. you can only see what you're looking at (obviously).

I did also try method 3 at the field stop itself and it was definitely no where near as sharp as on axis / method 1. about half as good id say, thats a notable loss of performance.

[andrew63]

Some interesting thoughts. As this lack of sharpness was evident in both of your scopes to give such a poor performance in the outer half of field, I'm wondering if it could be field curvature - can you bring to focus the outer parts of the view which are soft? Anyway you should get some useful feedback as there are quite a few on here with fast dobs using orthos.

andrew

[Stargazer_00]

I'm wondering now just how prevelant it was in the smaller F5 this morning. It's going to be clear tonight so will be collimating both scopes thoroughly tonight after i've i put them out to cool and will ensure it's as evident in the slower of the scopes as I noted in the first light post.

I could go and grab my dad's 127 mak (F13) today and give that a spin as well to see how much scope speed is an influencing factor here.

The moon is so bright now that I suspect ill be looking at it some more tonight. If plato is still well illuminated for observing then im hoping to try split that pair of craterlets

[alan potts]

Do Newtonians dobs need collimation so often, I have never touched my Mak/Newt and as far as I can see it's still as good as the day I got it and that's over 18 months back.

Alan..

[Stargazer_00]

anything over an 8 inch I read should be collimated every time you move it. only the primary but with nobs is easy to do b both with a laser in about 3 minutes in the dark

my 6" never goes out of collimation. the 10" doesnt much either I just always check them anyway.

[Qualia]

I always need to give my truss-dob's primary a tweak after setting it up and often throughout the evening-night - as it cools - it does need further tweaking, nothing hardcore, just a gentle twist of one of the primary's screws.

In the 4" f/10 I was pretty much happy with any EP I used but since getting the Moonshane 10" f/5 I have become a lot more critical. In the end I started using only the BGOs and TVPs because they were the only EPs which supplied what my eye wanted to see: amazing sharpness, excellent contrast, no flaring or ghosting. In the f/5 I have no problem keeping track of the given object (simply due to Shane's phenomal skills in building telescopes) and I have never noticed anything like curvature and lack of sharpness nearing the field stop when using either the BGOs or TVP.

Anyway, over the last three months, the situation got to such a state that I finally decided to sell all my other EPs (X-Cel LXs, Hyperions), all of them and use that cash to fund just one decent EP which would offer around a 2mm exit-pupil, half-my-aperture mag, and a little wider field than the BGOs or TVP. It was a toss up between a Pentax XW or Delos and in the end plumped for the latter.

Last night I was out experimenting and the 10mm Delos left me floored. I have never seen the given objects of the night sky looking like that in my life. Give me another week or so and I will try to offer some kind of review comparing the Delos 10mm with the BGO 9mm and TVP 11mm but for now all I can say is that it was more than worth exchanging all my EPs for just that one gem.

[Stargazer_00]

Awesome thanks for feeding my habit some more! I definitely fancy some Delos I think. Looking forward to the report mate.

[alan potts]

Qualia

I have the Delos 10mm and I have sold it as you know but it is still in the cabinet , I hope the 10mm Ethos is as good or I will be crying in my beer. I don't think there is much to choose between them apart fro the FOV and in the case of the Delos better eyerelief which is not a concern for me.

Alan

[alan potts]

Graham,

If you want an afternoon nap after a read, I wrote a review on the 10 mm Delos and it is in equipment reviews, it's a few months back now but I think it is still there. In fact there are reviews on the 6mm and the 4.5 to used in a few scopes.

Happy dreams,

Alan.