Which scope for me? My story…

[rikyuu]

Downsize and computerise?

I know the most common advice for beginners is to go for as large an aperture as possible and avoid paying loads for a computerised mount in lieu of a decent scope and I definitely agree with getting a decent scope, though now I don't place as much priority on aperture. In just one year, due to my unceasing curiosity, I've been through the whole cycle of small computerised mount, to large Dobs, to large EQ mounted scope, to imaging and back to a computerised scope (still imaging). Unfortunately for my bank balance, I tend to enjoy learning through experimentation,n so I've been through quite a fair mix of equipment.

My geographical situation is a small garden surrounded by rows of terraced houses, trees and a garage, in a city centre with country side to the south and a brightly lit dual carriage way to the east. So not the best!

I also have very little time in the evenings, so viewing is limited to about 3-4 hours in the winter and less in the summer when it doesn't get dark until late. It's also always cloudy, especially when the weather forecast says it will be, but also when it's meant to be clear!......and when it is clear the moon is up!

I thought I'd post this to show my experience as a (hopefully informative) alternative angle on which scope might be best for those choosing a scope. I think I have finally arrived at what is best for me (although no doubt I'll be changing my mind again!). Of course everyone's situation is different and people want different things out of astronomy. If there's one thing I've learnt, it's that there's thousands of combinations of equipment available to use and that no single setup suits everything. Here's my story! (Sorry for its rambling structure, but I'm writing from memory trying whilst to stick to the timeline)…..also please feel free to correct any glaring technical errors, as I am still learning!

Ps. Having written it now, it appears so complex that it will put off anyone thinking about it! But please don't be, this is just my experience, I just recommend reading as much as possible about it before deciding what to buy.

I don't know why it took me so long to get into astronomy, after-all I'm interested in the stars, photography and image processing. I think I was put of by the complex looking EQ mounts with knobs everywhere! Anyway in Feb 08 I bought the Celestron Nexstar 60 SLT, brand new for (what is now) a bargain price of £99. I knew nothing about it and rushed to test it out on a weekend when my family was visiting. It didn't appear to work for long despite trying (what I thought were) new batteries and I ended up sending it back for a refund. First mistake, I later found out that low batteries could have caused it to work incorrectly.

After reading about astronomy for a short time, I realised (or thought) aperture was king, so bought a second-hand F/4.7, 1200mm, 10" Dobs. Two problems quickly presented themselves; finding stuff and tracking stuff. The view of Saturn was superb, for a second, then it was gone. I also quickly realised it was nice to photograph an object to remember it and to show to others, my first step into imaging was photographing Saturn and the moon with a digicam through the eyepiece. I found moving the Dobs by small amounts was difficult. I quickly installed rollers, but still struggled. For finding stuff, I installed a digital tiltometer and rotary angle encoder, but it was still difficult for me to get the correct ALT/AZ location and track objects.

I decided tracking was the way forward. I unsuccessfully tried to build an equatorial platform and even built a wooden ALT/AZ mount controlled by parts of a Meade DS GOTO mount. It worked to some extent, but wasn't really ideal, so ended up buying an EQ6 mount, as this was the only one suitable for the huge 10" scope. By now I had also bought a Mintron 12V6; a very sensitive B&W CCD camera. Of course, the whole setup was a very heavy (50kg+), although very stable and it took some time to set up. It certainly wasn't portable and it was no mean feat mounting the 10" tube on it each time. The sensitivity of the setup was great, particularly with a focal reducer on the Mintron giving approx F/2.5. But the field of view was horrendously narrow, making it very difficult to find objects with the setting circles. The light pollution fog was quickly reached and the images were low resolution. I did have a c-mount zoom lens piggybacked onto the scope which did help in finding stuff when the Mintron was attached to it, but it was still time consuming and I often got lost.

It was also during this time that I had been reading a lot of books and internet articles about the subject and started to realise that aperture isn't always king (or at least it isn't an overriding priority), particularly for imaging in my particular location. I also realised that I was only imaging the easy to find stuff, due to my very limited time, such as the Orion Nebula and Pleiades. I did star hop to the Crab nebula once, but it took a while!

So based on: Heavy awkward setup, low resolution (actually low pixel count, ie. 700Kpixel) B&W imaging, high light pollution, very narrow FOV and difficulty finding stuff I decided to have a change…..again.

First quick stop was a Meade DSI to at least get colour images, but I wasn't satisfied, same issue of low pixel count and narrow FOV. Plus my archaic laptop wasn't really up to it.

Right then, also during this time, I realised (more than I had done before), that a smaller aperture was ok, as long as the focal length was smaller too (for imaging with the same camera), it's just that the 'magnification' would reduce ie. FOV would increase. I also realised that the potential resolution of a large scope (eg. 0.5 arcsec) would probably never be realised from my back garden and I would be lucky to get 2 arcsec, which is achievable with a 60mm scope. I also realised that even with a big scope, many objects visually (especially nebulas and faint galaxies), are going to look like a faint grey smudge or nothing at all. This really emphasised to me, the power of a camera to see many times more than the eye. Adding a long exposure or sensitive camera was like significantly increasing the aperture of the scope. What aperture would be needed to see a colourful Orion's nebula visually? Quite big I expect. Yet it can be easily captured with a few seconds of exposure with a camera. A smaller scope would just need a longer exposure (or more frames to stack). Visually, I would still see a faint smudge (although fainter of course).

Oh yes, then there's collimation, I think I was quite paranoid that I hadn't correctly collimated the reflector and wasn't getting the best out of it. Which is one reason I went for a nice semi-sealed refractor. Although by comparing the two, I decided the reflector was actually nicely collimated, but just too big.

So after at least a month of deliberation about what replacement scope to purchase, I picked up a C80-ED refractor from FLO. 80mm, F=600mm, F/7.5, ED optics. I thought I'd get a scope with well recommended optics and what a beauty it is. Visually, the image is pin sharp with great contrast.

(I also got a Skywatcher Skymax 127 Mak-Cass, another lovely scope with fantastic high power views, F=1500mm in a tiny package!)

The 10" Dobs was sold on at a bargain price. So now I had doubled the field of view with the Mintron, for a drop in brightness (F/4.7 – F/7.5, but the Mintron could cope) and a massive reduction in size and weight (12kg down to 2kg).

As this time, in the quest for a camera with a greater number of pixels and colour images, I started to look at DSLRs. I was amazed at how cheap second hand cameras were and quickly snapped up a Canon 300d. This gave me a fantastic FOV or 2 degrees with the C80 for wide vistas and with 6MP, the image could be nicely cropped for smaller objects. The imaging resolution was about 1-2 arcsec from memory, about right.

But, the problem of finding stuff in my limited time was still there. I was still focusing (pardon the pun) on the easy stuff.

I was also reading about imaging with ALT/AZ mounts. I like this type of mount as 'it goes where it's meant to'. Ie. Up/down and left/right is easy, it's not so easy to get your head around moving in RA and DEC and comparing it to what you see on a skymap. I read about long exposures on these mounts and found that around 30sec can be successful without suffering from field rotation. I found I could only take up to 30s exposures from my garden anyway, before the sky fog became too great, even with a light pollution filter. I also saw some images taken using a Celestron SLT ALT/AZ GOTO mount which were quite impressive. I was very keen on getting a GOTO and wanted a quick, easy and light weight setup.

So, rewind all the way back to the beginning, regretting sending back my original SLT, when the fault was probably due to the batteries (although I'd learnt a lot in the process), I went on the hunt for an SLT mount. The prices of the Nexstar 60 SLT had doubled and it wasn't easily available. I missed getting a couple of cheap second hand deals, but eventually found a new one for a semi-reasonable price.

It handles the C80 scope easily and is quite stable for such a light weight mount. The GOTO is a dream (for me), especially as I have it plugged into a laptop running Carte's du ciel (free). With the ASCOM driver (free), it tracks the scope position on the skymap on the laptop screen, fantastic. With the Mintron looking though the scope and hooked up to a 12" monitor above the laptop I can see the exact stars and objects appearing on the sky mapping software.

I don't think this detracts from learning the sky, I think it helps in a way. The main stars on the screen are labelled and I can see them in the sky. As I move across the sky and zoom in, I can instantly find the name of any object in view on the camera image. Now that I can set up find objects quickly, I can finally start to work though the 'Turn Left at Orion' book. The camera can be easily switched to the 300d. The setup is easily portable too, the mount scope and camera can be quickly packed up off to a dark site. I'm quite pleased with it and it works well for me. It's been quite a torturous route to effectively get back to where I started from (albeit with a better scope and camera), but a heck of a learning process and hopefully I'm more knowledgeable because of it.

I hope this helps in some way and doesn't just add to the confusion!

I emphasise again that this is just my experience and based on my knowledge of astronomy which may be wrong.

[kniclander]

wow . Great post -very interesting - a lifetime's scope experience in a year

the Mintron/ Watec approach sounds very interesting.

[MikeP]

Very good post. Do you think you have arrived at your final destination or will we be reading chapter 2 in a year's time?

Mike

[Helen]

Nice report, and useful stuff for newbies ...I worked my way down to a small scope...and then worked my way back up .. so I think a chapter 2 is likely!

Helen

[jgs001]

Great post, glad you've found a setup you're happy with. I've got a couple of small scopes, and have had one of them since day 1.

[Doc]

Just think how much you have learnt in a year....

I think I'm heading down a similar path to you. I have had the same feelings as yourself and keep edging towards a smaller scope but then on that special night, the dob blows me away.

[ZOG]

End of episode 1 ??

[SteveP]

Riky

A lovely tale in the pursuit of the best scope. There's a very useful answer to the simple question of 'what is the best scope?' Answer - the one you use most

It looks like you've arrived at your best scope .... for now anyway!

Steve

[The Warthog]

Great story and lesson! Aperture is king, until the damned thing gets too heavy and awkward to move around.

[marsan]

Excellent post.

Thanks for sharing your experience.

Would love to see some examples of the images from the Mintron and the DSLR.

[rikyuu]

I think I missed a couple of bits out!! Like a brief foray into LRGB imaging with home made filters on the Mintron and also a cheap (£12) 3MP digicam, which I removed the lens off for prime focus, high resolution imaging of the moon. This works quite well for close up images (the sensor is small with tiny pixels) and it can be set to capture a frame automatically every 2sec, but the image has some cross-hatching in the top left corner, I don't think they had prime focus astrophotography in mind when they designed it!

As for chapter 2, well, that will depend on whether I finally get to emigrate to Australia……cue a large pier mounted GOTO SCT! The visa is in the bag, just keeping fingers crossed for a voluntary redundancy payment to make up for the collapse in house prices which unfortunately was getting into full flow just as we got the visa.

And yes definately, the best scope is the one you use the most!!

[rikyuu]

Excellent post.

Thanks for sharing your experience.

Would love to see some examples of the images from the Mintron and the DSLR.

Thanks! I haven't done so much actual imaging with the Mintron, I tend to mostly use it to provide a live image on the monitor. I did take a photo of the ring nebula last year, which was actually a photo of the monitor display! I was quite suprised, I could see the central star live on the monitor! I've also done a couple of Orion's nebula, but that's an 'easy' target of course. My DSLR work is still developing (pardon the pun), but have had a few pleasing photos including a particularly nice moon shot which I posted on the forum. It's been cloudy for so long since I got it, I've only had a few chances to try it, but it's nice to be able to use it independantly of the laptop ie. stand alone, and of course it's a huge, high quality sensor for a bargain price. My main issue is with focusing, which I need to spend more time on.

[x6gas]

What a great post - thanks so much for sharing your experience.

I recognize a lot in myself from what you say, especially the learning from experience which can get rather expensive!

I went for a 6" goto Newt trying to balance portability / speed of set-up / ease of use and cost as I'm in a similar boat regarding lack of time. It's new so I can't say whether it will keep me happy for a reasonable period of I'll end up with a larger app. SCT!

Thanks again!

[Tom Redfern]

I swapped from a skywatcher 150pl to a skymax 127 for issues to do with weight and size. Im very pleased with what you might call a small scope. What you use the most is the best scope!

[wolfytom]

Brilliant post!

But I have a question...

The over-riding message seems to be that I'll see little of value visually and need to take pics to get value, whatever the size of the scope I pick!

Is that a correct interpretation?

I'm not currently interested in pics - I want to 'see' stuff,

Kind regards

Andy

[Capricorn]

Think the message is that even a 10" dob may not mean you see things. If you cannot locate and keep them in view then you are looking at a patch of empty sky.

Too much is made of aperture. I only know one person that can easily point a scope at a patch of sky and get what he wants or expects in view. How he does it I have no idea, nor do many others.

The other interesting point is I think that his first choice was probably close to the best option. A post on CN said the same aboiyt 6 weeks back. Follow you instincts or intuition, your first thoughts are probably right.

[KE400]

I found this an excellent post and very interesting to a newbie like myself. Thanks

[metz]

got to admit that was good reading and im now sticking to my refractor ...very good post

[collangm]

Being in the current position of deciding which scope is also best for me, I found this posting extremely useful and am now possibly re-thinking my whole approach in this important decision making process!

Thanks,

Gary

[Orion_the_Hunter]

What a great post!

This thread may be the one which makes me FINALLY decide

[West End Wendy]

Yes it is a great post. It's also nearly 2yrs old. I wonder what set up the OP has now…

I've gone down the small telescope and live camera route myself (ED100 & Watec). Ok, so it's low resolution, black & white, and you need a telly or computer to see the image, but I'm getting the performance of a 10" scope (at least) with the convenience of a 4".

There's always a compromise somewhere…