My First Telescope - Skywatcher 130P Image Tests

[blackparticle]

After watching Brian Cox point his DSLR up at the sky, take a photo and reveal stunning images I thought..

A) Really? Everytime I do a long exposure the stars streak across the sky.

and

I've really got to get me a telescope.

I do a bit of photography so I wanted something that would act as a suitable "lens" for the camera as well and not be overly complicated. I ruled out any sort of GOTO system as I wanted to learn my way around the sky rather than have a stellar tomtom do it for me. An equatorial mount seemed the right way to go. As this is my first telescope I didn't want to go nuts and just buy something really silly. Looking at a 10" Dob in a brochure pic and thinking, "I can carry that outside sure.." and then checking the specs.. Er.. No.. I set myself a rough budget of about £300.

So, after some research, a bit of umming and ahhhing and not trusting couriers to deliver fragile goods.. I finally went out to a shop that sold telescopes to have a look. In the end I bought a Skywatcher Explorer 130P with EQ2 mounting and it came in over £100 below budget as well.

The basic setup of the scope on the mount was fairly easy. I read through how to use the equatorial mount but to be honest, found it more fun just trying to work it out for myself by twiddling knobs and turning levers. Adjustment of a telescope seems to be quite an intimate process at times and I am enjoying my novice fumbling as it's allowing me to get to know my scope.

I don't want to talk about First Light too much as something I realised within the first 10 minutes of looking at Saturn that Astronomy is.. to some extent.. inherently underwhelming when compared to the images you can see on the internet. Yet, at the same time I "got it" as soon as I finally found M51 and could see.. the absolute faintest of imperceptible smudges. I'm never going to see those kinds of images with my eyes on a scope like this.. The magic of basic astronomy is found by thinking like it was 1611.. not 2011.

Before buying my telescope I'd managed to take a photograph of Saturn with my Pentax K10D camera and a Tokina 500mm f/8 lens.

I would imagine this is very similar to what Galileo saw 400 years ago. A planet or sun with two spheres orbiting it.

And that was enough to get me started.

To allow me to connect my camera I ordered a T-Ring and eyepiece adapter off eBay from Hong Kong for about £25. This allows for both prime focus and magnified images. I also spent another £30 on a GSO 4mm plossl to give me better magnification. I've also decided the supplied Skywatcher x2 Barlow lens is not very good.

As a test, I tried out some land-based photography first.

And then a prime focus shot to test absolute magnification of the digital image.

Optically, I'm quite happy with that.. especially on the prime focus images where no glass (apart from the mirrors) comes between image and sensor. Daylights shots at least allow for a fast shutter speed which is always helpful when trying to achieve a sharp image.

So, as it went dark I was getting quite excited about trying Saturn again. And just as Saturn started to become visible the clouds started to roll in.

The best image I managed to capture puts me somewhere around Huygens circa 1655 I expect. :-)

What I do know now is that on a clear night with dark skies I'm going to have so much fun. I've not even had a chance to spot the moon yet as it's been so late to rise. Now I know that will be impressive.

Hope this helps anyone thinking about their first scope, taking photographs and what to expect.

-bp-

[rowan46]

welcome to sgl, if you are interested in imaging planets pop over to the planetary imaging section and have a look at what they're doing with cheap webcams. Most people are using the phillips spc850 about £40. dslr's do take good photo's of the moon have a look at the lunar imaging section

[Ad Astra]

The images from your scope seems excellent, the appearance of some graininess as you increase magnification is normal, and your scope and camera seem to function very well together.

Saturn is a hard target for a standard camera. Small image diameter and turbulence make good photos difficult. Web cams take many short exposures, then use image stacking software to add all the best ones into a better image.

Try a prime focus shot of Leo or Virgo at lower magnification and I bet you become lots more satisfied with your setup! Lunar photos, (lots of light, short exposure times) should do very well, too.

Dan

[blackparticle]

I'm holding off thinking about webcams for now and concentrating on single shot images as that will help me improve my optical viewing as well. Thankfully, I'm blessed with very good eyesight and can fully appreciate the difference in quality when the image is viewed through the eyepiece rather than via a CMOS chip. I'd say it was as profound as the difference between reel-to-reel tape and an MP3.

I have just spent a while checking some of the other test shots I did and while the Skywatcher Super 10mm EP only shows very minor red/cyan chromatic aberration, the bundled 25mm lens is dreadful. The GSO 4mm is good on this front but is quite dark optically and I think is really only going to be useful for close-up lunar detail.

Which leaves me thinking I should spend the rest of my budget (approx £75) on a much better eyepiece in the 20mm - 40mm range?

Any recommendations?

[Ad Astra]

Which leaves me thinking I should spend the rest of my budget (approx £75) on a much better eyepiece in the 20mm - 40mm range?

Any recommendations?

I think a nice wide angle lens such as a 32mm would be fantastic. I'm in the US, so I'd say see what others here have to say about your local offerings. I use pretty basic plossl lenses most of the time and do very well with them. I spent all my $$$ on a new mount and a premium refractor, I don't have the cash (or spouse approval!) to go shopping for premium eyepieces.

Dan

[blackparticle]

I'll have a bit of a read I think.

One thing I will say though, judging on optical sharpness between prime focus and the different eyepieces.. The quality of the eyepiece makes a massive difference to the quality of the image, both digital and optical.

From a photographic perspective, the quality of the optics on the 130P are remarkable for the price and are actually way beyond the capability of all the EP's I have.

So I imagine this must apply to most telescopes?

[Ad Astra]

I'll have a bit of a read I think.

One thing I will say though, judging on optical sharpness between prime focus and the different eyepieces.. The quality of the eyepiece makes a massive difference to the quality of the image, both digital and optical.

From a photographic perspective, the quality of the optics on the 130P are remarkable for the price and are actually way beyond the capability of all the EP's I have.

So I imagine this must apply to most telescopes?

Certainly when you are talking about the EP's that come standard with the scope - this is absolutely true. Stock EP's can be terrible and are an area where Mfr's frequently cut corners. Even a cheap $40 plossl can be a massive improvement.

Dan

[blackparticle]

Talking of image stacking, I did do a run-off of 14 RAW files in quick succession.

I found some freeware called Lynkeos (as I am on a Mac) and had a go.

Compared to the single frame shot.. ok.. I admit that is somewhat of an improvement.

I'm calling this shot, "Newton - 1668"

[John]

From a photographic perspective, the quality of the optics on the 130P are remarkable for the price and are actually way beyond the capability of all the EP's I have.

So I imagine this must apply to most telescopes?

If they included good quality eyepieces with scopes they would have to massively increase their retail prices of course so they give you enough to get you going, but no more.

Many premium eyepieces cost more than the cost of the 130P for each eyepiece, sometimes much more

What you say about the impact that quality eyepieces have on the quality of the views is generally true although there are some scope designs that work pretty well with low cost eyepieces.

[EdF_uk]

Blackparticle,

Thanks for your post, I found it quite interesting. I'll soon be getting my first scope and was interested in hearing about your experiences and to see your first imaging efforts. From what I've read the eyepieces do make a big difference to the overall viewing quality. I'm getting the Skywatcher 200P and I understand that the supplied eyepieces aren't the best so I'll be upgarding those ASAP. Obviously there are a whole host of other factors that influence the quality of viewing too including the atmospheric conditions etc. I'll let you know what my viewing is like.

All the best

Ed

[blackparticle]

After some cloudy nights there was a break tonight. Still a hint of smog lower down but certainly worth another go at Saturn.

I'd been doing some tests with DSLR image processing as well and have found that pre-processing the RAW file in Photoshop is usually better than feeding it directly into the image stacker. This certainly seems to apply to the freeware version I tried at least with the filters in Photoshop helping clear the noise.

Anyway, my latest attempt.

I also tried some prime imaging on the 130P and here have hit a snag... While it's fine as a camera lens for land-based spotting.. The focuser doesn't travel back enough to focus stars.

I've since read some articles and it appears this is a common problem with all DSLRs and the 130P.

I even tried a hacksaw on the focuser as it appeared to be made of plastic to take off 1cm of tube but it still wasn't enough. << ( I DON"T RECOMMEND THIS AT HOME.. somewhat messy. ) .. But I'm sure there is a solution there and after a week with the scope this is like riding my first bike. It's fun, I'm learning, it's hinting at what is possible, it may get scraped and at some point it will get outgrown.

Before then though, I've set myself a few imaging check-boxes to hit first.

These are -

1. The Cassini Division

2. Jupiter and Moon(s)

3. A photo of the moon for my wall.

4. Any DSO.

That should keep me entertained. :-)