Saturn 23rd April 2011

peterako

Lovely viewing on the 23rd!



5x Revelation/GSO Barlow
Celestron G8N hybrid 8" Newtonian
CG-5 with RA tracking
Philips spc9000nc
wxAstroCapture

Postprocessing with Registax...a little over processed but I'm happy

Clear skies,
Peter

Ardent

Nice! What kind post-processing did you do and what does it look like unprocessed?

peterako

Hi,

Minimal post processing with Registax.

The 'over-processed' comment comes from me choosing to push all the wavelet filters to the mas....which resulted in the grainy pic.

Pre processing it's an AVI file/film.

Here's what it looked like after stacking in registax, but NO further processing.



I took the above, aligned the red/blue (atmosphere), some wavelet stuff, contrast and histogram, then reduced it to get the first image.

Will spend some more time with the captures when the clouds return and hopefully pull even better out of them

Clear skies,
Peter

Ardent

Love the colours in the unprocessed image! Are you using a filter? Also, is the blurriness due to over-magnification or effect of the barlow?

I have a 6" Newtonian and thinking of getting a barlow for it, was thinking of a TV 2.5x Powermate though, it gets really good reviews.

peterako

Hi Ardent,

The 2.5x Televue will knock the socks off anything I have....and be worth more than my scope

I would guess the blurriness is a lot down to pushing my magnifacation beyond the limits with a 5x barlow....and the difficulty that there is in getting focus spot on at that mag.

I use an IR/UV filter.

Some colouration will come from the atmosphere, some from the barlow and some from the lens in my telescope (it has one between the Primary and Secondary).

With a 2.5x barlow you may get a small image on the camera's chip though.

I look forward to seeing some images from you!

Clear skies,
Peter

Ardent

Thanks for that Peter. The idea is that the 2.5x will be primarily for viewing. I'm new to astronomy and imaging is a little way aways at the moment.

Looking at webcams though and I see the one you use is highly regarded for astrophotography. I'm a little confused about it's effective power though, i.e., if it were an eyepiece what would it's focal length be? I see reports from 4mm all the way up to 20mm? I get a lovely clear - although slightly small - view of Saturn with a 6mm eyepiece so someting in that ballpark would be ideal.

Another noobie question - can you see nebulae/galaxies with the naked eye or do you need to engage in long exposures and astrophotography to see them?

Thanks,
A.

peterako

Hi,

I recon my webcam is roughly the same as my 6.4 eyepiece. So roughly what you want.

What scope do you have? (I see it's a 6" newtonian, but what make/model/mount?)

On Nebulae.

Yes, you can see them visually. Depending on your eye you'll see them as white splodges....and with time will see shape.

My eyes show The Great Nebula in Orion with a blue tinge, and I can see cloud like formation.
M51 I can just about see spiral form with averted vision.

To get the detail you see in photos you need a camera.

Our eyes are not great at picking up colour at these brightnesses, Cameras can.

On pure naked eye....I can see Andromeda on a good clear night....as a splodge with some short faint wings.

I've only begon to delve into shots of nebulae etc. So am not the best to answer any detailed questions.
But basically most of the detailed shots you see are made up of an hour or more or stacked images taken with a DSLR taking 30s or so exposures.

Sometimes through a telescope sometimes through their own lenses.

Check out IFAS for some great Irish astrophotographers and astronomers.

Friendly bunch too

Enjoy!!

Peter

Ardent

I purchased a Celestron Omni XLT 127 SCT and an additional Celestron C6-N Newtonian OTA. The C6-N doesn't have the magnification of the SCT but has much greater light gathering ability. The barlow will be for the Newtonian.

The mount the XLT 127 came with is a CG-4 mount. Good mount but tracking is manual. Planetary and lunar shots initially I think.

Had a go at M51 last night and failed miserably. Need to get a Telrad finder and Turn Left At Orion. I can see this turning out to be an expensive hobby!!

At least, I picked up your webcam at a really good price:
http://www.morgancomputers.co.uk/shop/detail.asp?ProductID=6313&CategoryID=452&SubCategoryID=522

peterako

Will be interesting to see the imaging result comparison between the scopes.

Had my eye on that site for a while. they started at £8 odd :eek:
Still a bargain!

Have processed another capture form the 23rd April night:



This time with 2.5x Barlow so more like what you were thinking of in terms of mag.

Clear skies,
Peter

Ardent

Finally got my barlow and had my first stab at photographing Saturn tonight. This was taken with a Celestron C6-N, 2 stacked barlows (Powermate 2.5x + Celestron 2x) and a Philips SPC900 web cam. Not the worst!

peterako

That's pretty good!

Saturn's well past it's best for the time being so great first capture!

Clear skies,
Peter

Ardent

Hey Peter

How did you get such great colours in your photos? My unprocessed ones were very washed out, almost back and whte! The only filter I used was a cheapo UV/IR filter for the webcam.

peterako

Nothing by design!

What software are you using to capture?

What frame rate, gain etc?

How long is the capture?

wxAstroCapture (free) for camera control and capture is far superior to the Philips VLounge software that ships with your/our webcam.

What are you using to process your capture?

The two barlows stacked may have been too much. Try it with the Powermate alone. It'll be a smaller image but the optics on the TeleVue should be much better than the Celestron + PowerMate.

It's possible some of the colour in my images are false.

Colour may have been added by:

Optics (possibly the Barlow as I get similar colours with my Orion Optics newt)
Atmosphere
Registax (coping with the red/blue 'shift')

I also use GIMP (The image processing software!) sometime, but I don't think I used it on these images.

Also....an 8" scope will capture much more light than a 6" scope so maybe that's the ultimate difference?

My unprocessed ones of Saturn are yellowish, just like the colour I see with my eyes through the scope at highish magnification.

Your image is still great, especially as your first!

My first Saturn (with an Astromaster 130EQ, a Celestron 2x Barlow, €8 eBay webcam and hand tracking):





Clear skies!!
Peter

Ardent

I used SharpCap for the capture and hand-tracked the planet for maybe 10 minutes. I think it recorded the AVI at 10 fps. Then it was a case of deleting the worst frames and importing the AVI into Registax and letting it work it's magic.

You're probably right about the second barlow. I find with just the TeleVue on, there's plenty of light and clarity and I am able to use filters with it. Also, with the second barlow, I'm pretty sure I'm pushing beyond the max useful magnification of my scope.

peterako

I'm still an AstroCapture Newbee...so Caveat Emptor!

Try captures of 2 to 3 minutes.

In any case, with hand tracking you may want to use shorter captures (?)

Also experiment with 5fps and 15fps.

I do most of my captures at 5fps and some at 10fps as I seem to get an unreasonable amount of noise above 10fps.
Most of my captures are < 3 minutes.

A more expensive camera will allow higher frame rates.

What kind of mount are you using?

An RA motor may be a very good investment if you plan to do much photography.

Now....all we need is another clear night