Uranus / eyepieces

stevejack (Steve) · #1 29-01-2009, 12:48 AM

I saw Uranus for the first time over the weekend - I knew it was close to Venus so a quick search placed it in the eyepiece. Quite a thrill I have to say - and seeing Neptune for the first time a couple of months ago was also a highlight.

One question though - It could have been because it was so close to Venus, or quite low to the horizon (or both) but Uranus appeared quite brown (no joke intended here!). How should it normally look colour-wise?

All I need now are some quality eyepieces... trying to decide between saving for the 13mm Nagler t6 and the 13mm Ethos. At double the price it's a tough choice! Whichever I choose I'll keep it for life but other than field of view is there any significant benefit in getting the Ethos over the Nagler for a 10" dob at f/5? In terms of future-proofing my eyepiece collection, is it really that much BETTER (+$500!)?

Matty P (Matt) · #2 29-01-2009, 03:07 AM

Hi Steve,

Viewing the outer planets is definitely a thrill just like oberving some of the closer planets like Saturn and Jupiter.

I remember Uranus to be a blueish green colour when I last had a look at it. I'm not sure why it appeared brown. The only reasonable explanation I can think of is that being quite dim and low in the horizon, the visible colours changed maybe due to dust or smoke in the air at the time.

Sorry I can't comment on the eyepieces.

troypiggo (Troy) · #3 29-01-2009, 08:40 AM

Out of interest, what sort of magnification was that at? What was your eyepiece and focal length of scope? Sorry, I'm new to this and trying to get a feel for it all.

stevejack (Steve) · #4 29-01-2009, 12:38 PM

Troy, np prob - I was using 15mm and 9mm GSO eyepieces, The 10" scope is f/5 (1250mm focal length). I also had a barlow but am not happy with it at all - it really softens things up (probably becuase it's cheap as well!). I'm hanging out for quality eyepieces/barlow now and just trying to research what will match my scope the best.

Matt - thanks, I was pretty sure it was supposed to have a diff colour - And yeah, there was a little dust blowing around as well which wouldn't have helped. After last months dust storm I noticed a bit of crunchyness when I was inserting eyepieces! :O
I'll have to remedy that.

Paddy (Patrick) · #5 29-01-2009, 02:00 PM

Hi Steve,

I'm no expert but I imagine that the brown colour is due to the refraction of the atmosphere and dust. It's usually a lovely bluish green colour.

As for eyepieces, I like my 13 mm Nagler, but have to say I was pretty blown away looking through a 13 mm Ethos in my 16" at Snake Valley last year. There will be a lot of people who know lot more about the quality of these eyepieces than me and I think John Bambery (ausastronomer has had some recent IIS posts that you might find helpful. If I had a spare $500, I'd go an Ethos over a nagler if I didn't have either. I don't think that I would invest in an Ethos already having a Nagler unless cash was not an issue. Both are quite spectacular.

As you say, you'll have your ep for a long time, so its worth investing in.

stevejack (Steve) · #6 29-01-2009, 10:43 PM

Yeah thanks for your thoughts mate - its really a matter of thinking; i'm starting an eyepiece collection from scratch, and it doesn't matter how long it takes me to acquire them... so I may as well do it properly

That said, I'm sure i'll be just as happy with the 13mm t6, and in a lot of ways i would probably be better off getting the Nagler + 24mm panoptic for the same price. Decisions, decisions....

renormalised (Carl) · #7 30-01-2009, 12:03 AM

The ol' hand grenades (Naglers, if you get either a 32 or 40mm EP, you'll see what I mean

) are excellent EP's. However I here that the Ethos EP's are even better. Really though, it's a pick of two excellent EP's. You can't go wrong with either of them.

Ick!!!!...make sure you clean out your scope's tube and the focuser of any grit and dust!!!. That'll ruin your focuser quicker than anything, and it won't do the optics any good either. Be like rubbing them with sandpaper!!!.

Uranus is a blue-green colour. I'd say it was the dust that was making it brown. That and you viewed it low to the horizon...blue light gets scattered the most close to the horizon. That's why sunsets are red....red light, because of its longer wavelength, doesn't scatter as much and you see it more easily.

Paddy (Patrick) · #8 30-01-2009, 09:46 AM

Quote:

Originally Posted by stevejack

That said, I'm sure i'll be just as happy with the 13mm t6, and in a lot of ways i would probably be better off getting the Nagler + 24mm panoptic for the same price. Decisions, decisions....

The 24 mm Panoptic is a very nice ep - When I upgraded my scope, I got a williams 28 mm UWAN as I was increasing my focal length and thought the 24mm pan wouldn't be enough of a wide field eyepiece. I thought I'd sell it, but I still use it heaps because of the quality of the optics. It also barlows nicely - I used it a lot with a GSO Barlow before I got my 13 mm nagler and found it very useful. If that was the combo you were going to go for it might be worth getting the Pan first with a barlow and then getting the nagler later. you'd then cover both focal lengths with a quality eyepiece. Good barlows are not too pricey.

Oh, and the 13 mm Nagler is a very modestly sized ep - another point in its favour IMO

stevejack (Steve) · #9 30-01-2009, 12:37 PM

That sounds like a great idea - If I grab the 24mm pan + barlow It'll be a vast improvement over what I have now and will give me some time to decide on a dedicated 13mm EP.

Is the TV 2x big barlow recommended for the Pan?

At a cost of around $700 for that combo it's getting very close to the cost of an ethos :\

Quark (Trevor) · #10 30-01-2009, 01:44 PM

Hi Steve,

For viewing the planets at high mags I think the orthoscopic design is far better than a plossl. They provide excellent contrast and very sharp images. Uranus at 6mm in my 16" F4.5 Newt is a small greenish disc and Neptune appears to me as a small grey disc about half the diameter as Uranus. The detail through the 4mm and 6mm otho's, depending on the seeing, is stunning sharp as a tack.

The field of view when observing a planet is irrelevant. My shortest F/L eyepieces are 4mm & 6mm orthoscopic's then I go to a 9mm Nagler.

There is no comparison to the quality of image the otho's give compared to the Nagler. If the seeing is good enough for better than 6mm I would always go to my 4mm otho rather than the 9mm Nagler in my triplet 2 x Barlow.

I actually find the 9mm Nagler of greatest use when I am Imaging Saturn and Jupiter with my DMK and a 2 x or 3 x barlow. I slip the 9mm in to initially align the field, this is where the wide field of the Nagler excels, then I very gently swap back to the DMK and the planet will appear on the screen of my Laptop in the IC Capture field.

Don't get me wrong regarding the quality of Nagler eyepieces, my 31mm Nagler is just in a league of its own. I also have a 14mm Meade series 4000 Ultra wide which is also a stunning eyepiece, the one I do about 80% of my observing with. But for high magnification I think the orthoscopic design stands alone.

My 6mm and 4mm orthoscopics are at least 20 yrs old, I have heard good reports about a Japanese brand, not sure but think they were Abbe or similar name.
I am sure you will get other opinions on this subject, but these are my thoughts.

Regards
Trevor

fragchamp · #11 02-02-2009, 02:37 PM

TV 8mm plossl is a near perfect planetary IMHO. Magnification won't always be enough though and eye relief, well my eyelashes touch the housing if I want to see the whole FOV. Uranus and Neptune, not exactly spectacular but the achievement of hunting them down is something.

Also, unless you have a tracking mount, the sharp FOV is an important factor in my considerations.

stevejack (Steve) · #12 02-02-2009, 03:25 PM

Ahh yep thanks guys - your views on the eyepieces are really helpful and i'll do some research into the orthoscopics as well.

I should have been clearer in my message - I am after eyepieces for DSO viewing only (with maybe a quick peek at the planets, but nothing too serious). So I am after 1 or 2 quality eyepieces for this purpose to use with my 10" f/5 dob.

TBH, I am leaning towards a 13mm nagler t6 which will give me plenty to look at for a while and won't bust the bank (too much).

I have read that there are problems when barlowing the 24mm Pan, and that a Powermate is recommended to correct the issues - have I got this right?

Paddy (Patrick) · #13 04-02-2009, 04:27 PM

Quote:

Originally Posted by stevejack

I have read that there are problems when barlowing the 24mm Pan, and that a Powermate is recommended to correct the issues - have I got this right?

I don't know what others' experiences are, but I have never had any problems with the 2 Barlows that I've owned (GSO 2" 2x and TV 1.25" 2x)and the 24 Pan. I have compared the 13mm Nagler and 24 Pan barlowed and found no difference in image quality and have not noticed vignetting. Had a good second hand 13 mm nagler not come up, I'd still be using the Pan with the 2x TV barlow. I used this combo heaps with my GSO 12" for DSOs, perhaps more than any other configuration.

stevejack (Steve) · #14 04-02-2009, 04:55 PM

Quote:

Originally Posted by Paddy

I don't know what others' experiences are, but I have never had any problems with the 2 Barlows that I've owned (GSO 2" 2x and TV 1.25" 2x)and the 24 Pan. I have compared the 13mm Nagler and 24 Pan barlowed and found no difference in image quality and have not noticed vignetting. Had a good second hand 13 mm nagler not come up, I'd still be using the Pan with the 2x TV barlow. I used this combo heaps with my GSO 12" for DSOs, perhaps more than any other configuration.

Thanks Paddy - Was this the standard TV barlow or the more expensive "big barlow"? I may be reading this wrong but from what I gather the big barlow accepts both 2" and 1.25" eyepieces??
Is there any other difference between the two (quality wise)?

There is a second hand 24mm Pan up for sale at the moment that I would love to grab if the barlow works that well!

Paddy (Patrick) · #15 04-02-2009, 08:27 PM

Quote:

Originally Posted by stevejack

Thanks Paddy - Was this the standard TV barlow or the more expensive "big barlow"? I may be reading this wrong but from what I gather the big barlow accepts both 2" and 1.25" eyepieces??
Is there any other difference between the two (quality wise)?

There is a second hand 24mm Pan up for sale at the moment that I would love to grab if the barlow works that well!

I use the 1.25 inch 2x Barlow, currently at Bintel for $139. I haven't tried the 2" big barlow, but have been very happy with the 1.25 and the 24 Pan.

ColHut (Colin) · #16 04-02-2009, 11:55 PM

You might want to luck at the 6mm Lunar/Planetary Eyepiece Comparison on cloudynights

http://cloudynights.com/item.php?item_id=1935

cheers