how can I darken objects that appear too bright through the scope.

[AlexN]

Hey,

I've viewed Jupiter over the past 3 nights, and have noticed that more often than not it appears very bright, almost full bright (lacking any detail). Usually I can see the 2 top red bands, but the majority of it appears as a white disc.

Is there any tips anyone can give on how to bring more detail?

I'm using an 8" dob with a combination of eyepieces (10mm, 25mm and a 2x barlow) but each time the result is the same, I've even tried with the cap on the the scope removing the 2" cap on the side, but that seems only to make the white disc appear dim.

Can anyone suggest something to try with my current equipment, or suggest a filter that I can use to get some more detail?

Thanks.
alex

[OneOfOne (Trevor)]

Some coloured filters can be used to enhance details, can't remember which colour for Jupiter, but most people find (as do I) that any improvement is marginal, if at all.

To reduce the light level, you don't want to stop down the scope as it will also reduce resolution, so you could try a neutral density filter or I have a "twin polariser" filter that comes in handy for full Moon, so something like that may help.

When viewing Jupiter, however, don't expect to see anything like what the guys here will get with even the crudest imaging setup! In my C11 I basically see the bands, the spot and that is pretty much it.

Have you checked the collimation? Just swing to about a 2nd mag star and put in your highest magnification. Either side of focus you should see concentric rings (diffraction) around the centre star.

[AlexN]

would a lunar filter work? I have one of those, although i didnt try it last night due to being buggered and heading off to bed at around 2.30.

I havent checked the collimation since saturday (when the scope went for a 400km round trip to an observation) probably time to give that a fly too...

Cheers for your input....

[Dietmar]

Alex, just power up magnification!
and: rejoice on that pair of highly sensitive eyes you have (-:

[iceman (Mike)]

I was gonna say the same as dietz. Use a higher power if the seeing can support it.

Oneofone, i'm surprised if all your C11 can see is 2 bands. I think you just need to look in the right conditions. In very good seeing there's an enormous amount of detail visible. You also need to look for a while to let your pupil contract a bit if it's too bright.

Observing detail on Jupiter is a skill, and takes time to improve at.

[programmer]

Hi Alex.

I was viewing Jupiter in my 10" dob from Melbourne last night, and could make out 3 distinct bands at 200x despite less than great conditions. But it certainly is bright, I can see what you mean. I had not observed Jupiter before and was quite surprised. If the conditions had been better I would have upped the power which would have dimmed the disc but possibly at the loss of detail. Just my 2c worth as a beginner!

PS: Maybe a dedicated planetary eyepiece would be the go, as they have special coatings for the task. I can't wait to get a decent high power EP for great views of the planets!

[AlexN]

i was at max magnification for the eyepieces i have... 10mm in a 2x barlow. im buying a 5mm or a 3.5mm this week... so we'll see how they go.

[programmer]

Hi Alex

Do you think it's worthwhile getting a dedicated high power eyepiece like a 3.5mm? Maybe get a more usable 7mm and barlow it on those rare occasions when the seeing is extra special and you can use the 342x in your 8". Which EP were you thinking of getting?

[[1ponders] (Paul)]

Next time your up at Ron's Alex I'll bring along my 2.5x powermate and 6mm TV Radians. If the conditions allow it you won't let me leave with either when I want to go home

[AlexN]

yeah a 3.5 in an 8" probably is a bit over the top. A 7mm in my barlow will provide similar magnification and be a more usable EP...

I was perusing myastroshop yesterday and got myself a red dot finder and a widefield 30mm 2" EP, Thought it best to have a better think about a high power eyepiece, and hence I put the idea forth...

1ponders - Sounds good, Im actually quite keen on another trip up that way, visibility up there is paramount compared to kallangur...

I was also considering a LPR filter... any suggestions?

thanks again everyone.

[OneOfOne (Trevor)]

Originally Posted by iceman

Oneofone, i'm surprised if all your C11 can see is 2 bands. I think you just need to look in the right conditions. In very good seeing there's an enormous amount of detail visible.

Actually, I only got a chance to look at Jupiter a couple of times last year before I got the collimation sorted out so my statement is probably a bit misleading At the moment I would have to wait until 3 or 4 am to be able to see it as there is a tree in the way...Saturn becomes visible by about midnight at the moment, but when I have to get up at 5:45 to go to work, it is a bit late in the evening to be viewing into the wee hours. I could go out to the front yard and get a much better view, and I would be able to read the newspaper under the street lights while waiting for the scope to slew

[programmer]

Alex, please give us the details of your EP purchase. I've been purchasing also.. you might've seen my thread on the subject. Some interesting links at the end of that thread.

[AlexN]

The EP i bought is this one...
http://www.myastroshop.com.au/produc...asp?id=MAS-174


I havent seen your thread as yet - but im off to work now (arvo shift is awesome when ur hobby involves staying up to the wee hours to view..)

I've been viewing Saturn anywhere from 11pm onwards, Jupiter becomes visible from around 12, and at its best by 3.30ish where its around zenith...

Please continue to post any suggestions and questions - i'll be back at around 11.30 to read up and reply... hopefully this ****ty weather goes elsewhere for this evening..

Cheers guys.
Alex.

[programmer]

Originally Posted by AlexN

The EP i bought is this one...
http://www.myastroshop.com.au/produc...asp?id=MAS-174


I havent seen your thread as yet - but im off to work now (arvo shift is awesome when ur hobby involves staying up to the wee hours to view..)

Nice EP! Interesting you got the 2", you must get some great "being there" views with that FOV. Not sure about the skies down my way tonight though

[AlexN]

Yeah.. im looking forward to it arriving on monday.... skies are clear as tonight so im off to the back yard!

[g__day (Matthew)]

Alex - ANdrews has the same eyepiece listed for $99 Andrews
80° UltraWide (UW) EyepiecesOutstanding 2" 80° UW 30mm A$99



I bought one yesterday - very nice!

[AlexN]

g__day - Thanks, but what I had failed to mention in the above link is that Myastroshop had a factory 2nd EP in stock, which was 100% defect free, apart from saying 20mm on the barrel rather than 30mm...

With this being the only defect listed, and the price being $59!!!! I got on to it quick snap (i didnt mention that because i didnt want someone snaking me and getting it before i could).

I was assured that it was a 30mm, and otherwise flawless, and was given a 30 day risk free trial, wherein i could test it for a month, and if i found anything else wrong, i could return it..

It arrived this morning with my red dot finder, and a lengthy inspection found nothing amiss. However typical of our fine hobby, the day i get new toys to play with is the day the sky turns black and buckets rain.... Fingers crossed for tomorrow night being clear so I can post some results.

[AlexN]

glad to report that the clouds buggered off for about 40mins at about 1am. I am STOKED with this eyepiece. Its razor sharp!! I didnt have the whole sky to look at, but had a brief glance at the following...

N6397 - Never managed to spot it before tonight.
N4755 (jewel box) - found this EP allows me to see more colour
N3372 (Eta Carinae)
N3532
N3293

Alpha Centauri and Acrux were visible as doubles despite the magnification,

Oh, And what a gift from the gods a red dot finder is I was going crazy with my finderscope