What are you "supposed" to See ?

[mkbrogers (Mat)]

Hi all,
Bit of a silly question coming up , but a bit of background first.
I purchased a CPC11 a few months ago and I have been using as much as time permits - but havent really gone into any deepsky viewing yet - still trying to learn about viewing the planets first.

My equipment is :
CPC11
Televue 13mm Ethos
Celestron Plossl eyepiece kit
Celestron 2x Ultima Barlow
Televue Powermate 2.5X and 5X
Imaging Source DBK41AU02
and other bits and pieces.

I have no problem doing the alignment of the scope and finding along with setting the tracking to track targets.
So far Ive only really focussed on viewing the moon and primarily Jupiter - I'm one of those sort of people that keep looking at the same object until Ive seen all I can see.

I also dont believe that the scope needs collimating as based ont eh 'how to articles' and resources - the images as to a collimated scope is what I see when going through the steps.

Ive used the camera to take Moon footage and stacked the images in Registax and got some semi decent shots there. Ive tried imaging jupiter as well - but I must have overexposed as it was just all White - though I did capture some "blobs" of its moons as well in the footage.

When observationally viewing I swap out the eyepieces and try different combinations to try and achieve the best possible 'image' in the eyepiece that shows the most detail. This goes well with the moon , but heres where my quesitons come into play re Jupiter and any of the other planets as I move on.

What Should I be able to see of Jupiter ?. (let alone the other planets)

Using a 40mm eyepiece I can see 4 moons and I can make out 3 largish bands around Jupiter. I place in the Televue 13mm and the 'image' doesnt really change that much. even putting in the powermate or barlows - the image gets bigger but the detail doesnt (maybe it shouldnt - thats 1 question ??)

Ive been reading these forums and have seen people comment on being able to view the red spot , or see the moon shadows on Jupiter as they pass by.

Are these Visual Observations or is this mainly using CCD imaging ? If they are visual observations then what am I doing wrong to be able to not see this detail.

Its slightly frustrating, and what caused me to ask these questions (up till now I thought that what I was seeing was really good) is that I was reading the Nov/Dec Issue of Aust Sky & telescope and on page 65 there is a picture of NGC7662 with a description describing that this is what you would expect to see with a 8" scope working at around 100x.

If that picture is what a 8" scope would see surely the CPC11 would be able to view better than that ?

To put it in perspective - replace the blue snowball in that picture with Jupiter and that is sort of the view I am getting. Maybe this is right - i just dont know. < for those that have the magazine that is>.

My concern is that if I cant view the detail in Jupiter (being the biggest planet) then what am I really going to see when trying to find Neptune or some of the outer planets ? This is not to mention what happens when I try to start viewing the distant galaxies and other deep sky objects.

This is really hard to explain in words I know - but any advice would be greatly appreciated.

Are my expectations unrealistic, have I got it all wrong or should I be seeing more than I currently am ?

Thanks
Mat

[dannat (Daniel)]

your equipment should deliver very good visual results - I would post and ask to meet one or two of the canbera guys o here who are visual observers and look thru their equipment. One i might suggest is baz from asign observatory - google asign & look him up - i think he would give great advice

I feel your frustration, what is the focal length of your scope f/l . if the seeing is no good you cannot push the magnification or you'll get blurry images.

[mkbrogers (Mat)]

focal length is 2800mm (110inches). with a focal ratio of f/10.

[erick (Eric)]

One thing, Mat. The photo of the planetary nebula on page 65 will show a lot more intensity of colour than you will see by eye. But I guess the general resolution of the nebula would be somewhat like the photo. Cannot say for sure - I'm going after that one later in November for the first time.

I do know about shadow transits of Jupiter. Through my previous 8" reflector, in reasonable seeing conditions, I could certainly see when they were underway. And if I watched intently, the seeing would settle for a second or less every so often, and give a very clear view of the distinct shadow on the bands.

Agree with suggestion. Get together with someone with experience to see if you scope seems to be performing up the the high standard that it should be.

[BC]

Hi there,

I'm certainly no whizz but I understand your concerns. Firstly the picture on Page 65 you refer to is "similar to the area an 8" scope would show" etc, not the same as what you would see through an 8" scope. I would venture to say that image was done with a camera/imaging. You won't see those colours in a planetary nebula with your eyes.
When I first got my 10" dob I was rather dissolutioned by what I could (or could not) see. I had built expectations based on web-based descriptions of people's experiences (not on glossy pictures), and found my views didn't match. One of the things people say is that you learn to view over time, and I think that is true. I see much more a few years on than I did at first. There are a few other things that factor in however. The 'seeing' is very relevant so if you have picked a bad night, that's unfortunate and you might not know a bad night when you see one at this stage. Cooling the scope is also super important and I believe SCT's take longer than newts. Canberra has big differences between day/night temps (I know, I live nearby), which can require more cooling. I had the experience of taking my scope in the car a week ago to show some others the views and it got heated up a bit. The subsequent views of Jupiter were appalling and disappointing. The bands were visible but I couldn't focus. On a good night I can see the great red spot and shadows of a passing moon and even swirls in the bands, but the image is pretty small. You won't be filling the eyepiece with a wondrous image of Jupiter, but you should be able to see a small wondrous image.

I'm sure other will add their thoughts.
Bruce

[mkbrogers (Mat)]

thanks for the reply Eric, im taking a leap that if you can view the transits from your 8" then I should definitely be able to see this from the cpc11.

[mkbrogers (Mat)]

Bruce,
Thanks for the feedback - I do use a SCT Cooler - I purchased it from overseas for the CPC11 - I let it run for around 30 minutes prior to using the scope.

Maybe part of the problem is that I have done too much reading trying to get all the right pieces of the puzzle and not enough time playing the pieces.

I'm definitely not seeing the swirls of clouds ..thats for sure - would love to be able to see that .

[Whizgig (Eugene)]

Well I have an ebay 6" x1400 F/4.5 Newton and I can see them and the red spot as well, But before I collimated the scope everything was blurry but now its fine and I can see everything fine and in perfect focus. So maybe it dose need to be collimated if you cant see it properly.

Whiz.

[WadeH (Wade)]

Hi Mat,

Your scope should be more than capable of seeing lots of goodies! Especially with the 13mm ethos and powermate. (215X & 538X respectively).

Funny you mention NGC 7662 as I had a look at the Blue Snowball for the first time last night and it looked in size and contrast just like the picture you refer to but without the definition. Just a large bright fuzzy blob (13mm nagler @ 76X). I'll try for higher mag. next time. Your set up should do much better I would expect.

The GRS is definately observable visually. As are the major gaps in the rings of Saturn. And thats just with a 200mm @ 1000mm f/l.

When you get around to DSO's I would suggest getting an eyepiece near 32mm for a wide fov for nebula and glob's.

Good luck and have lots of fun!!

[Bassnut (Fred)]

From my experience, you just cant compare urban viewing to CCD pics, at all. CCDs are vastly more sensitive. At f10 and 2800mm, FL eye ball viewing doesnt compare to even ordinary CCD pics.

[coldspace]

From my experience with SCT you need to have the collimation spot on to get nice sharp images.
Alot of people have these scopes and they are not collimated very good and the image performance suffers. So make sure the defraction rings on say a mag. 1 or 2 stars are nice and round on either side of focus. Just defocus the star a very little bit with say a 9mm eyepiece and you should see the onion rings.
When I first got my Meade 12er its views were excellent, but you should check the collimation all the time, I can easily see great detail through my scope when it is spot on with the colimation.
I remember a friend of mine saying up at Astrofest a few years back he went around a checked most peoples scopes both Newt's and SCT and he found most were out a little and some a lot.
After re-colimating the bad ones for these people they had a very nice night at the eyepiece compared to the night before.

Regards Matt.

[g__day (Matthew)]

My suggestions would be:

1. Add a feather touch 10:1 focuser (reduces mirror shift and greatly improves focusing)

2. Photocopy a Bhatinov mask onto clear A4 transparency and use this to check focus

3. Download CCD inspector v2.06 (from CCDWare) - use it for a month free trial with say a DSLR and perfect your collimination - it really does help!

Once collimination and focus are optimised - that leaves only seeing - you'll know you have your gear in top set up for the night!

Matt

[acropolite (Phil)]

One thing that nobody has mentioned is that the GRS is only visible at certain times, you will need some prediction tables to find appropriate times. Don't forget that times are usually UTC and have to be adjusted for local time.

[Geoff45 (Geoff)]

I don't know how the old guys did it, but here are some interesting quotes from The Planet Jupiter by B M Peek (1958)
1. With a 2" telescope, bearing a magnification of about 60, the shadows of the satellites may be readily seen as little black dots .....upon the disk of the planet.
2. A 3", working under good conditions will show that the belts are not entirely regular, but show darker patches or condensations.
3. An 8" is probably adequate for all purposes; a 12" certainly is.

The main sort of work he is discussing here is the timing of features as they cross the central meridian of Jupiter, which he claims can be judged to within 2-3 min, latitude of the belts, using a micrometer, colour observations etc. A lot of these guys worked with 6-8" scopes. Amazing!

Geoff
BTW, the pic in my avatar was taken with a 4", so a small scope certainly has the resolution to show a lot of detail.

[Geoff45 (Geoff)]

Originally Posted by acropolite

One thing that nobody has mentioned is that the GRS is only visible at certain times, you will need some prediction tables to find appropriate times. Don't forget that times are usually UTC and have to be adjusted for local time.

Here is a great bit of software to show what's happening with Jupiter.