Pelican region in Ha @ 1.3"/p - homemade mount test

[Tom How]

Grabbed a few more hours of darkness on Saturday night before the Great Rains.

Testing and evaluation continues on the homemade telescope mount but at the end of the session I did 3 x 30 mins exposures on the Pelican region with the Ha filter.

1.5 hours of data is very low for this kind of Ha work but the data was better than expected so I decided to post it in this section. I'm sure the processing could be improved but I'm horrifically out of practise.

The bright sky glow at this time of year makes things difficult, but the Ha filter does help a lot. The pelican is pretty much the brightest Ha region in the sky at present, so photon-wise it is shooting fish in a barrel, but I must wait for darker skies and longer nights to get the fainter stuff.

Full report on my doings on saturday night

http://astro.neutral.org/astronomy_blog/blog/item/2011/06/another-astrophotograhpy-test-on-homemade-telescope-mount

Full details:

3 x 1800s with Astrodon 6nm Ha filter

Artemis 285 (Sony ICS285 sensor)

8inch F5 skywatcher Newtonian

Homemade EQ mount

Autoguided with PHD via a BW LX modded webcam on a homemade off axis guider.

Calibrated and stacked in maxim and spoilt afterwards in photoshop.

[roundycat]

30m subs is certainly pushing the boundary and the small, tight stars say a lot for your guiding and, probably, PE. I can't ever recall seeing a picture as obviously close-up as this with such fine detail except for those taken up a mountain and as far as I recall there aren't any of those in S'oton. Good detail on the gas jets as well. The whole thing just needs a little extra contrast for me as well as being North up!

Dennis

[Catanonia]

wow, loving your DIY EQ mount... What an effort...

The picture just shows what amatuers can do, brilliant.

Also loving the homemade garden fence observatory, exactly how I made mine, cheap and cheerful

[rfdesigner]

Is that a bow shock I can see in there?

Looking very good so far.

Derek

[ollypenrice]

Very impressive and congratulations on the mount. I often wonder if a very long spring, like a clock spring, could not be built into a mount to drive out the backlash. It ought to be able to deliver constant pressure for the kind of duration required, no?

Olly

[Tom How]

30m subs is certainly pushing the boundary and the small, tight stars say a lot for your guiding and, probably, PE. I can't ever recall seeing a picture as obviously close-up as this with such fine detail except for those taken up a mountain and as far as I recall there aren't any of those in S'oton. Good detail on the gas jets as well. The whole thing just needs a little extra contrast for me as well as being North up!

Dennis

North is relative

I know what you mean about the contrast, but it didn't seem to be in the data, for reasons best know to itself.

I think the skyglow and moon didn't help, but something not right, I agree.

[Tom How]

Is that a bow shock I can see in there?

Which part of the image do you mean?

[Tom How]

wow, loving your DIY EQ mount...

Also loving the homemade garden fence observatory, exactly how I made mine, cheap and cheerful

I'm glad I'm not the only one. I always think people spend far too much money on observatory. But maybe I'm just poor.

[Tom How]

Very impressive and congratulations on the mount. I often wonder if a very long spring, like a clock spring, could not be built into a mount to drive out the backlash. It ought to be able to deliver constant pressure for the kind of duration required, no?

Olly

Now you are into a fun area... DEC guiding at high resolution is a pain. It isn't really the backlash in the final drive... it is more the "slack" in the whole reduction set and drive belt BEFORE You get to the worm wheel part.

For example, a guiding pulse of 100ms might do nothing. The gears then relax again. Another 100ms pulse, and then another 100ms may also do nothing. However, a single 125ms pulse may move it too far!

The guiding software tries to cope. Normally it can be tuned out by mechanical adjustments and fiddling with the guiding options. However you can't arbitrarily tighten the timing belts: Timing belts need a touch of slack to work well.

Not a problem in RA as it is always moving.

I have been pondering if it is possible to somehow "hold the tension" in the whole gear train between pulses. It might just be as simple as unbalancing the timing pulley on the output from the DS box with a tiny lead weight (or indeed a spring). Something to look into.

[MikeD]

Fantastic mount and a great image.

The contrast looks good to me. IMO too many images of this region have the contrast pushed too far and it all starts to look a bit unnatural, but at the end of the day it's the imagers prerogative.

Mike.

[Coco]

Excellent image..

Super blog by the way... very enjoyable reading

[rfdesigner]

Which part of the image do you mean?

the tip of the pillar.

[Tom How]

ah, yes, That thing.

I understand it is correctly called Herbig-Haro 555, one of the HH class of objects

Herbig?Haro object - Wikipedia, the free encyclopedia

Here is a better image of the region

Herbig - Haro 555 in [sII], Halpha and [OIII] from Stinger 450 Classical Cassegrain

(be sure to click onthe Highest resolution link)

[Tom How]

Excellent image..

Super blog by the way... very enjoyable reading

Thanks Guy.

Just as every man should have a shed, he should also have a blog.

Today we are trying to get rid of all the dark matter.

Astronomy, Astrophotography and Telescope Blog » The Death of Classical Gravity (and Dark Matter!)

Not sure if Dark Matter includes these rain-clouds however

[Tom How]

Fantastic mount and a great image.

The contrast looks good to me. IMO too many images of this region have the contrast pushed too far and it all starts to look a bit unnatural, but at the end of the day it's the imagers prerogative.

Mike.

I agree with you Mike. There is also a great temptation to over-sharpen this region as well. Some imagers go completely over the top and the results look 'orrid!

[rfdesigner]

ah, yes, That thing.

I understand it is correctly called Herbig-Haro 555, one of the HH class of objects

ah.. thanks for the link, I'd looked around for an explanation but didn't turn anything up.

None of the other images I could find showed it much better than yours and hubble doesn't seem to have been pointed at it.

Derek

[Tom How]

.... and hubble doesn't seem to have been pointed at it.

Derek

Yes, I was surprised that I couldn't find a hubble image of the region.

[jsigone]

great image and mount. Makes me want to try and build my own GEM

[RobH]

Great result Tom, you must be especially pleased

30 minute subs are tricky at the best of times, and it's a testament to your skill that you are producing them with such perfect stars on a mount you've made yourself.

If you don't mind, how much do you think it cost you, and what's the payload?

Cheers

Rob

[Tom How]

Great result Tom, you must be especially pleased

30 minute subs are tricky at the best of times, and it's a testament to your skill that you are producing them with such perfect stars on a mount you've made yourself.

If you don't mind, how much do you think it cost you, and what's the payload?

Cheers

Rob

Thanks Rob. Still more work to do improving it - but that is half the fun. Get something that sort of works, and then tweak I really need some slightly longer nights for testing.

I've done my best to discuss cost and pay-load issues on this page

Homemade GEM german equatorial telescope mount - how I made my own DIY mount for astrophotography

[Tom How]

Due to large number of questions, I have had a stab at a price/parts list with links.

http://astro.neutral.org/mount-costs2.htm

When I do DIY projects, I'm usually loathe to spend money unless I feel it is important. The money spent above is therefore money well spent.

There are many alternative ways of solving the various problems, some of which are cheaper, and some much more expensive, but this is the route I took.

These are today's prices including 20% vat.

[saturn5]

I'm glad I'm not the only one. I always think people spend far too much money on observatory. But maybe I'm just poor.

Or like me,just poor and lazy:D

Brilliant result.A great reward for your efforts.

[dc509]

Love it - wish I was so practical...

d

[darkside]

wow stunning image taken with a homemade mount:headbang:

[peter shah]

you cant ever spend enough on this hobby...IMO...my wife would disagree... i would spend loads more if i had the money

that mount is very impressive and the results from it are superb....i wish i was skilled enough to pull off something like that