bad seeing or ?

[vindictive666]

hello all

for he first time in a few days i managed to get a couple hours of viewing in last night


i checked out m42 with the 32 mm 2 incher and i could see the faint greenish glow, brilliant view :)


scanned the milky way with the 32mm and came across some clusters and one with what looked like one with a nebula (iam gonna have to get a chart one day :) )

by this time jupiter was up had a long look at different times but seeing was shocking
still seeing a lot of heat waves which i am assuming is turbulance of jupiter being to close to the horizon ?(this was aound 9.15 pm ) can anyone confirm this please or are my optics still out ? i must admit that as jupiter rose higher it became clearer saw the difference in the 2 eq bands and the four moons stood out as well as for trying to focus jupiter it seemed to be very critical a bit too much one way or the other it went out of focus real quick ?

no sight of color at all (using the 15mm plossle ) also put the lid with the cap removed as well that mede jupiter look dark but a little in color ? does that make any sense ?

does anyone else have this problem with jupiter (i got a feeling i might have to wait until jupiter is a lot higher)

i must say that when i used my small refractor on jupiter i saw the four moons and a definite color on jupiter
clearly, as when viewed thru the dob it very pale white looking any hints at what i might be doing wrong perhaps ?


allso had a quick look (very quick) at the moon bit of a boo boo that was i had a bright patch in front of my right eye for a good while :) i must get some moon filters :)

(i am very happy with the 32 gso 2")

(a bit dissapointed with the view iam getting of jupiter thought but will persist not sure when the next night will be because ive got clouds again today plus that so and so of a centre bolt is playing up again even with the spring washer if i didnt need it to turn i woulda weld the damn thing in place :) )

[iceman]

It's definitely because of a) bad seeing and b) close to the horizon.

There is a huge difference when Jupiter is overhead, so you should probably wait until 10-11pm to get the best views.

If there's a lot of shimmering when you see it in the eyepiece, like looking through water at it, then it's almost not worth bothering and you should concentrate on DSOs for the night instead. :)

[vindictive666]

thanks mike

moon was up as well i did try to look for the lmc but too bright :)

[[1ponders]]

Maybe a planetary filter might help bring out some of the colour. I sometimes find that its just too bright and I end up using my moon filter or a light colour planetary filter. Definately helps bring out the contrast and to a certain degree the colour, but it does dim it down a lot.

[westsky]

As Mike said it sounds like bad seeing and maybe a warm scope, how long did you have the scope out for before you looked at Jupiter?
a 12" dob will take a fair while to cool in our warmer months
I set my scope up around 5pm then I dont bother using it till around 7pm and being a SCT it takes longer to cool than the Dob's, by around 9pm the optics have cooled and the image's I see are better than at 7pm.
if the moon is close to the gas planets I find the image tends to wash out somewhat.
Try letting the scope cool for longer if you can.
cheers

David.

[vindictive666]

thanks people

had the scope out since about 6.15 6.30 pm

had dew forming on it as well but no the mirrors :)

[rmcpb]

The lack of colour is probably due to too much light gathering by the scope!! Sometimes you can get too much of a good thing. If this is a problem try a simple offset mask on your scope.

Get a bit of cardboard and set it up to cover the front of your scope. Cut a 4" hole on one side and see if that helps with the colour. It effectively turns your 12" f5 into a 4" f15 which would be a great planetary scope. I do this with my 8" scope on the moon to great effect, Jupiter is not so much a problem with an 8" scope.

Worth a try anyway and would like to hear of the success or failure of the experiment.

Cheers

[vindictive666]

hi rmcpb

ive tried it with the dust cap with the over 2 inch hole thats in it (it has a removable cap) and jupiter was a lot smaller with a bit of color:), ill try it with some cardboard and a 4 inch hole and see how that goes :)

and write it up with the results :)

[toetoe]

Not that i can get a lot of detail but, i find a great deal of diff with the time of viewing Jupiter. Often i view around 5.45am and find it very good. In the evening time i notice a clarity diff. I do not have good EP`s as yet but i am slowly working out better ways to view with the EP`s which came with my scope. Is this my imagination or are there others out there who find this as well. ??

[ballaratdragons]

Hi Vin,

The cover with the hole in it for the 12" is useless. (read thread 'Hartman Mask'). The hole in the factory cover makes it an f23.

The shimmering waves are a combination of horizonal atmospheric distortion and mirror equalisation. I have the same scope and find that if I turn the fan on 5 mins before viewing the mirror equalises. As for atmosphere, wait until about 10p.m. for the start of excellent views of Jupiter.

In your 12" with the 32mm you should be getting a lot of bright green in Orion Neb! Maybe you have a light pollution problem.

[vindictive666]

yep the light pollution was the good old moon :)

ill try anothe look when it aint there :)

i thought i had some cardboard for a mask but what i have aint big enough :)

[ving]

hi vin, i do the same as rob. I have a 80mm hole tho. the extra contrast given is great during bad seeing.

[Starkler]

I have never seen green in the Orion nebula.
Even in an 18 inch scope I only saw pinks and grey, but never green . Goes to show that each persons eyes are different.

[Dave47tuc]

Try to View the Planets when there high in the sky.

Also the Morning is better than evening.

Another trick is view the Planets in twilight. Try it and see what you think:D
Saturn is good for this at the moment.


I have only ever seen green in Nebula. Some say grey.
I keep saying all eyes are different.:whistle:

:astron:

[ballaratdragons]

My sons see bright green in Orion Neb as well. Must be hereditary, or that it is Orion Nebs colour. (and I didn't leave the Moon Filter in again, ha-ha)

[janoskiss]

Ken, Remove the moon filter!!

[ving]

i see a bright green in all my EPs 15mm and above. my 9 and 6.5 show a darker green. I think your eyes have problems resolving greens geoff :confuse3:

[Starkler]

I have no colour blindness issues . In my work as a tech I have to be able to see colour coded wiring etc and have been tested for it.
The difference is seeing colour at low light intensities. Perhaps the cone cells of my eyes arent as sensitive as for some other people.

My eyes are different in other ways also. Towards the outer portions of the field viewing through nagler eyepieces, I see coma or similar abberations where other people see none.
It would appear that my eyes dont cope with the steep light cone from the nagler.

[MiG]

As far as I know, at low light levels it's not worth paying much attention to what colours our eyes see.

I'm guessing that the green comes from the fact that our eyes are most sensitive to green. We're probably seeing no red, no blue, and a smidgen of green rather than the correct blend of the three.

[ballaratdragons]

Vin,

<b>Just a further thought:</b> If you get a Moon filter you can use it on Jupiter. As Laurie said "too much of a good thing" is right. I find that my 12" can, at times, collect too much light and Jupiter is one of those times. Jupiters bands stand out beautifully with a Moon filter as it cuts the glare. A Neutral Density filter also works but is practically a Moon filter anyway.

12" on Saturn is perfect and does not need filtering. I tried the Moon filter on Saturn and it lost too much light! It was a dark sphere with very, very faint rings. But for the Moon and Jupiter I recommend a Moon filter (or an ND) for a 12" dob.

Just another addition or alternative to making a mask.

p.s. Don't forget to unscrew the filter when you are finished using it. I often forget and wonder why some objects are too dark and hard to see. lol

[Vermin]

I had some moments of incredibly still seeing early on Saturday morning using my 4" refractor.

I saw white ovals and festoons on the edges of the equatorial belts for the first time on Jupiter. Woohoo!

However owing to Saturn's low altitude I could only just make out the Casini division occasionally.

[ballaratdragons]

Tom, which EP did you use? My 500 Series 6.5mm plossl just doesn't cut it for that kind of detail.

[Vermin]

I was using a Televue 3-6mm zoom set at 3mm, giving about 180x at 45x per inch of (unobstructed APO) aperture. The image was smallish, but quite detailed at times.

I also tried a 5mm Radian in my Televue 2x big barlow, but went back to the slightly sharper image with the zoom ep.

I tried barlowing the 3mm at 2x, but my Televue Panoramic mount was just too shaky to be of any use at that magnification. I'm sure the scope and seeing would have supported more magnification and am now considering obtaining an alternative mount for this OTA (when finances allow). A portable EQ mount for tracking at high mag. and digital photography is required methinks (EQ5/6??)

As I said, there were moments of exceptional clarity, I have not seen the sky that still since buying my scope years ago. Hopefully it's partly due to the location - a friends farm 30min out of the city - as I plan to make the site my regular dark sky site for use with the 16".

I had set up the scope outside (in the very cool air) an hour or so before and that helped too.

[ving]

I've had seeing like that. :)
...once :(