Telescopes and star gazing.....

Moore the merrier as The Sky at Night heads for its half-century

Ali

Unfortunately I didn't get to do any viewing as his 'scope was packed away at the back of the shed with a load of gear in front of it that has been put there in storage temporarily. Shame as it was a reasonably clear night.

I have read 'Astronomy Now' for a number of years so I suppose that there is a degree of loyalty there. The Sky at Night is very good as well and I find them quite similar. The Stargazing Guide is certainly excellent.

My dad buys Astronomy magazine, which is american but he prefers this to the others.

Regards

Mark

Will have to dust off my Pentax LX this digital camera Canon Powershot A40 is just not up to it or is it me ??

Manfred,

I thought you would have had some some comments to add to this thread, as I know it is something you know a lot about. Hope all is well in Germany. Star gazing in Namibia

Regards

Nic

quote:

Originally posted by Roy T:
I have often used this method when taking long exposure shots where I wished to capture the movement of flowers..

Now that's what I call a long exposure!

quote:

That pink noise is back again (the orange glow is clowd) same as in the star trail shot in Wales (on page1 of this thread) and I’m still not sure what it is……??? I attached the viewfinder cover this time, and had lens hood on/off which made no difference at all, the same pink effect top left of frame is in every shot……anybody any ideas….???

I seem to recall reading somewhere that the pink noise / 'fogged' area you refer to is located at the point on the sensor closest to where the image data is read out. This causes the sensor to become very slightly warmer close to this point, causing increased noise which is seen as the fogging you are seeing.

I forget whether this was a CMOS or CCD specific problem (ie the two dominant sensor technologies IIRC) and/or how/whether this was exposure duration dependant.

Not much help I know.

/dl

quote:

Not much help I know.
/dl

Not at all - it's a 'possible' explanation that I wasn't aware of... Thanks!

My wife and step son conspired to buy me a Mead GOTO 4"scope for Christmas. Still reading the owner's manual to figure out the GOTO features, but got a really exciting look at the moon last night. Next up is Pliedes, now that I got the alignment dohicky figured out today. A little chilly outside these nights, though.

Norman

Hi Nic,

nice to hear from you.

Namibia has a very dark sky and it was a great experience to observe the spendid objects of the southern sky under such perfect conditions.

Here in Germany I live in a very light pollutet region, so observing dim deep sky targets is nearly impossible. Sometimes I make a two or three day trip to a darker area 160 kms away ( Eifel ), where the conditions are much better.

My telescopes are:

TEC 140 Apo-refractor
Celestron C8 Schmidt-Cassegrain
GSO 12" Dobson

Best wishes

Manfred

OK, so I got a tantalizing look at Saturn tonight with the 4" Meade telescope I got for Christmas, and of course I want a closer view! The stock eyepiece is 26mm:

1) How much can I reasonably push the eyepiece magnification?
2) Do I buy another Meade eyepiece, or some other glass?

Norman

Hello Norman,

a simple rule is:

Aperture of the scope in inches x 50 = max. magnification. In your case 200x.
To find the magnification of a given eyepiece:
Focal length of the scope : focal length of the eyepiece = magnification

So, if you want a more power than with your 26mm EP, you must buy one or two EPs with shorter focal length, maybe a 15mm and a 9mm. As I don`t know the focal length of your scope, I cannot say, what suits best for you.

Eyepieces with shorter focal length have often a very short eye relief, so it is uncomfortable to look through them. Consider a LE ( = Long Eyerelief ) EP like the Vixen LE-Series.

For more information ( astronomie, telescopes, eyepieces ) look:
here
and
here

Best wishes

Manfred

Hi Manfred,

Thanks very much for your response. I can quote a few specs from the owner's manual: The model is Meade's ETX-90PE with 1250mm focal length, so the 26mm EP yields 48X. They list the "maximum practical visual power" as 325X, so even Meade's own Super Plossl 6.4mm would not be out of the question (is a 2mm eye relief considered long in that size eyepiece?). The owner's manual says that a useful selection of EPs would be SP 9.7mm, SP 12.4mm, and a SWA (super wide angle) 16mm. The thought of Saturn filling much more of the field of view really is exciting!

My remaining question is: Should I simply stay with Meade glass, or should I spend a little more for another manufacturer's, such as the Vixen you mention above? Sort of like my wife always insisting on Nikon lenses over the less expensive competition.

Oh yes, one more. The Barlow type magnifier is mentioned in several places. Is that a useful device, or does it muck up the image?

Regards,

Norman

Hello Norman,

325X is far too much magnification for a telescope with only 90mm aperture. Saturn would be unsharp, very dark and you will not see more details than using an EP with 180X. Even this magnification is not possible every night, very often the air is unsteady and bad seeing avoids high power viewing. There is one exception, for splitting very close doubles you need sometimes very much power.

So, if you aren`t a keen double star observer, your highpower EP should be at the most in the 7mm region (=178X), better around 10mm (=125X).
In addition to this high power EP and your 26mm a third EP in the 14 - 17 mm region is highly recommended.

Meade EPs are of course ok, but there are many strong competitors in the market. The very best imo are the Tele Vue Naglers, they are very sharp, have a good eye relief ( 12mm or more ) and offer an extreme wide field of view - 82°. Its a pleasure to look through them. But....they are extremly expensive, especially here in Germany. However, if you buy an excellent eyepiece, it will be a keeper and it is possible, that you still use it with your second and third scope. If you don´t want to spend so much money, Vixen LVW ( made in Japan ), Orion Stratus and Baader Hyperion ( both made in China ) are all good widefield EPs with excellent eye relief.

Keep in mind, that your ETX accepts 11/4" EPs only, 2"ers would not fit, they are too big.

Using a Barlow lens adds two more lenses with four optical surfaces in the lightpath of your scope, so a little loss in image brightness and sharpness may be the result. I dont´t use a Barlow with my telescopes, there is no need to do so, as I have enough EPs.

All the best

Manfred

Hi Manfred, and again thank you for sharing your expertise.

Googling Tele Vue Nagler, I see that you are quite right about the prices. However, I am wondering if there is a reasonable alternative in Tele Vue's 8-24mm zoom, which is priced ($240) just a little less than a single Nagler type 6 EP ($290). This might be a very cost effective entry into having a nice range of Mid to High range magnification with reasonable optical quality? Again, drawing on my wife's photography experience, there are both high and low quality zoom lenses; she just got a Nikon 200-400mm zoom for ridiculous money that takes incredible pictures that rival fixed focal length lenses in that range. Might I reasonably expect the same from such a zoom EP from Tele Vue?

Regards,

Norman

Hi Norman,

no, unfortunately the Nagler Zoom ist not playing in the same league. The field of view is rather narrow ( between 55° and 40° depending on focal length )and the sharpness is not as good as it is in a Nagler T6. It is a mystery for me, why the TV zoom is named "Nagler".

Oh, I forgot, the Naglers T6s are small and light. This is not the case with the Vixen LVW, Orion Stratus or Baader Hyperion, these are bulky and heavy. As your scope is not very big, it is possible that you will get balance problems with these EPs. Ask your dealer.

Just a remark as a consolation. Here in Germany the price for a T6 is about €320 = $400, so you can be very happy with the US-price.

Best wishes

Manfred

Hi Manfred,

Thank you for sharing your expertise. I have read quite a bit on the 'net in the last two days as well and I need to digest this information to decide how to proceed. Part of the problem is that I do not know serious I will remain in this hobby. It seems to be quite a feat of alchemy for Nagler to maintain quality and the incredibly wide field of view in an EP as small as the T6, particularly compared to the earlier types. One consolation is that TV Naglers seem to maintain their value quite well on the secondary market, much like Naim. So, there seems to be little downside to making a sizeable investment.

Regards,

Norman

Happy New Year folks!

Just an update from me....haven't been on here in a while...and I've just read through this thread again - thanks for all your info/input, Manni - you are very lucky to have 'astronomy holidays' something to aspire to!

Bought myself a couple of Christmas pressies in December, Philip's books - Practical Astronomy, and their Guide to Stars and Planets.

I've been out a couple of times too, and my gorgeous other half accompanied me on one trip - she was first to spot the Andromeda Galaxy with the bin's after some directions from me....much to her fascination....

I was out on our patio a while back and took this shot of a lunar halo.....


Then last night, after waking in a pool of sweat at 2am (I now feel like shit - sore throat/cold/flu bug thing) I wrapped up and went out again with my camera. And just as I stepped outside and looked up (NE of Orion) I saw one of the longest/brightest meteors I have ever had the pleasure of seeing - amazing!!

It was a very clear cold night and it made me think we possibly could do a great deal of observing from our garden - bonus!! I also had the bin's out and could clearly see the colour of Saturn through them.....makes me think what I could see with a scope!!
Can you find Saturn in this pic.......


Cheers,
Ali

Hi Ali,

on the right side and a little bit above of the bright object ( I suppose it is the moon ) you can see three bright stars, wich form a triangle. The right one is the planet Saturn, the other stars belong to the constellation Leo. The star left and below of Saturn is Regulus, the brightest star of the constellation Leo. In the right upper corner you can see Castor and Pollux = Alpha and Beta Gemini.

All the best

Manfred

10 out of 10 Manfred......

A question.....

We don't want to rush into buying our first scope, but, as I said earlier, after gazing up at the stars the other night I feel we could do some great observing from here in our garden, much to my delight - and if it's easier to do we are more likely to do it more often!!

Which has got me thinking again about the type of scope we should go for.....???

As usual, and as with the stereo, my initial budget has crept up slightly. Ended up thinking about a Meade ETX 125PE, popped into Black and Lizars up here in Aberdeen and spoke with a very helpful member of staff. She recommended the Meade highly and I was surprised by it's size! Portability was, and still is, a priority and this scope seemed to fit the bill.

However, I feel I could be limiting myself with the size of aperture 5" - compared to what I could get for that sort of money....although the bulk of a reflector of equivalent cost would make portability nearly impossible, I'd imagine....

Guess I'm kind of answering this question myself aren't I......what takes priority for me/us.....

Problem is - I'm not sure!!

Without seeing a galaxy, planet or nebula through any scope I have no idea what my priorities are going to be....
Is the size of aperture on the ETX going to limit my view of deep sky objects, in which case a reflector would be better, or, are we going to get the most out of the ETX being able to take it down to Wales or out into the country from time to time as well as using it in the garden...???

I'm going to my first AAS (Aberdeen Astronomical Society) meeting tonight, and we are both thinking of joining. Their talk tonight is "a guide to telescopes" so it should be interesting. Hopefully over time I can get a look through other members scopes to make our own decision on what to go for easier.

I'll keep you posted, but any further advice would be greatly appreciated.....

Cheers,
Ali

Hi Ali,

the 125 ETX is a very fine scope. It is portable, has Goto, so you will not waste time by seeking objects and is a good performer on the moon, the planets and bright DS-objects.

However, one thing is very important in astronomy: aperture rules!

So, a 8" Dobsonian telescope will show you far more as it has more lightgathering capabillity and more resolution. DS-objects, barely visible in a 5", will become obvious and, if the air is steady, the 8" will show you more detail on the planets. As a typical 8" Dobson has a focal length of about 1200mm and a 2" focuser, you can get better widefield views using 2" EPs compared to the ETX. This is important, when you look at extended objects like some open clusters ( e.g. the Double Cluster in Perseus ).

A 8" Dobson weights about 15 kgs and is rather bulky, but the setup time is very short, as you don`t need any power supply or cables. You set up the rocker box, then comes the OTA and you are ready. But, you have to find the targets yourself, there is no goto and there is no drive. Finally, the 8" Dob is far cheaper than the ETX.
When you will meet AAS tonight, try to get a chance to look through different scopes. That will help you to make the right decision. And do not forget, the perfect all-purpose scope does not exist.

Best wishes

Manfred

Thanks for that Manfred, I'd figured the perfect all-purpose scope doesn't exist!!

Makes me wish we could buy two scopes, one larger one for the garden and a smaller, more portable one, for trips out and about....

I'm more than happy to learn my way around the skies, it's all part of the fun!

But, another important factor that I have to take into consideration is the height of my gorgeous other half - she's 4'10 and I don't think she'd be too happy clambering up a step ladder to peek into a dobsonian every time! This was what made me think of the ETX Maktusov-Cassegrain type of design in the first place, even over the newtonian reflectors....

Time will tell.....

Cheers,
Ali

quote:

But, another important factor that I have to take into consideration is the height of my gorgeous other half - she's 4'10 and I don't think she'd be too happy clambering up a step ladder to peek into a dobsonian every time!

What about a wireless link from your soon to be installed CCD to your other half sitting at a big screen in the warm nursing something warming in her hands? Sounds good to me and I expect her.

Hi Ali,

in a 8" f = 1200mm Dobson the EP is at a max. height of about 4'. So there should be no problem for your wife, to look throught that scope. She does not need a ladder.

Best wishes

Manfred

Manfred - you are so right....but I had no idea this was the case until last night!!

I went along to the AAS meeting last night, which was good and then tagged along with a few of the guys who were going out with their scopes! The dark sky site is on forestry commission land about 15 miles west of Aberdeen, and after the guys were set up we had a good couple of hours observing.
Scopes were a 12" Meade LightBridge Dobsonian, and a 10" (I think) Meade LX90 with GOTO.

WOW

First view was M42 Orion Nebula, the LX90 didn't reveal as much detail as the Dob but both images were amazing! You could clearly make out the inner stars, the 'petal' surrounding them, and the outer swirls or gas/dust....totally cool.
We also looked at M31 Andromeda Galaxy, M81/82 - in one view through the wide field-of-view Dob, various cluster and other stars, but my most memorable moment of the night was seeing Saturn and it's rings for the first time, a sight and experience I will never forget!!

I set my camera up and forgot about it while we were observing and after twenty minutes this was the result...



It was really interesting seeing the Dobsonian in action, and, as Manfred says, the height wouldn't be a problem for my gorgeous other half, but it is not suitable for astro-photography due to the mount, something I am keen on.....
So, I'm quite happy to wait and get a look through some of the other members scopes (which they encourage) and see which direction we wish to go....I don't think I'd get away with an LX90 though.....

And then tonight, I managed to get a spectacular look at Comet McNaught!!
4.30pm in the Western sky, above where the sun is setting, it can clearly be seen with the naked eye. I had the bin's on it earlier and it is quite something! Unfortunately I haven't invested in a longer lens for my Nikon yet, kit 18-70mm at full zoom, then a crop in photoshop produced this......



If you can get out of that last meeting tomorrow, or are free and have a clear sky in the west - get out there and catch it before it goes, it'll only be around for a couple more days if that.....

Cheers,
Ali