My first attempt at the SCP (and polar alignment)

Russ59 · #1 22-07-2012, 02:20 PM

Okay, please refrain from laughing, (because I know I would) but here is my first serious attempt at a DLSR on an EQ6. But first some background info.

I unpacked my EQ6 for the first time since purchasing it some months ago, flicked through the instructions, then threw them to one side, bolted it all together and proceeded to polar align.

The mount was as level as possible, the latitude set, then I slowly panned the azimuth until I could find the asterism near the SCP. I used the tutorial here: http://www.iceinspace.com.au/63-466-0-0-1-0.html but my light pollution was simply too much. I can easily find the SCP with my small binos but not though the polar scope built in to the EQ6.

I wasn't going to spend all night attempting perfect PA as the night was getting old and, well I was simply getting impatient

I aligned it as best as I could, mounted the DSLR on top and took 5 x 20 seconds of the SCP. Afterwards, I stacked them in Deep Sky Stacker . Agree, its a pretty shonky and far, far from a perfect result but it proved that I can achieve something. It also proved that I will benefit from a permanent shed/pier setup because I don't know how your guys and girls polar/drift align with a portable setup

I dip my hat to you all.

But having said all that, I'm determined to at least find sigma Octanis in the polar scope this week!

Russ

multiweb (Marc) · #2 22-07-2012, 02:49 PM

Not laughing - that looks real good. You've got the data acquisition sorted out. Now it's all processing. Nice shot.

Don't stress too much about perfect polar alignment.

Russ59 · #3 22-07-2012, 02:52 PM

Thanks Marc,

See that grainy area at the bottom, is that noise from the camera or an issue with processing?

Russ

Russ59 · #4 22-07-2012, 02:54 PM

Quote:

Originally Posted by multiweb

Not laughing - that looks real good. You've got the data acquisition sorted out. Now it's all processing. Nice shot.

Don't stress too much about perfect polar alignment.

The TIFF image looked better but when I saved it as a JPG and reduced the size, some of the detail was lost.

multiweb (Marc) · #5 22-07-2012, 02:59 PM

The grain is noise but it could be caused by the stretching of the pic. I looks a little clipped which means the ends of the histogram (full dynamic range) got clipped. Can you post the original TIFF somewhere and send a link? Then we can have a look and play with it.

Russ59 · #6 22-07-2012, 03:34 PM

Thanks Marc, just to clarify, I used RAW (.CR2 format) then converted them to TIFF to use in Deep Sky Stacker. After processing I saved it as a TIFF, opened the TIFF file in Paint Shop Pro and resized and saved as a jpg. Is this the best approach?

The TIFF file is 68Mb - too big to post here but I'll look for a hosting site and post the link.

silv (Annette) · #7 22-07-2012, 05:06 PM

I like it, too! You caught Carina nebula's pink glow! How beautiful is that!
Hope you are pleased with the first light of your mount.

If you can mark the position of the tripod legs on the ground once you are satisfied with your alignment - that makes it heaps easier the next time you set up. People sink bricks in the grass and mark the leg positions on the bricks, for example. You can get it quite accurate like this, soon, and quickly repeatable, too.

Enjoy!

loki78 (Jon) · #8 22-07-2012, 05:16 PM

Yeah Russ I like it too especially for a first time. Can you tell us more about what equipment you used and camera settings etc.

I find it most helpful when seeing pictures to get all the details about what was used to take them also

multiweb (Marc) · #9 22-07-2012, 05:21 PM

Quote:

Originally Posted by Russ59

Thanks Marc, just to clarify, I used RAW (.CR2 format) then converted them to TIFF to use in Deep Sky Stacker. After processing I saved it as a TIFF, opened the TIFF file in Paint Shop Pro and resized and saved as a jpg. Is this the best approach?

The TIFF file is 68Mb - too big to post here but I'll look for a hosting site and post the link.

Yeah that's cool but you need to keep your eyes on the histogram left and right prior to save to scaled TIFF or you'll clip your data.

Larryp (Laurie) · #10 22-07-2012, 05:22 PM

Good photo! I can see sigma octantis quite readily

stephenb (Stephen) · #11 22-07-2012, 07:25 PM

Good first start there Russ

This is around the same level I'm at - DSLR on a GOTO mount. You should be able to achieve some good widefield images in no time!

Russ59 · #12 22-07-2012, 07:43 PM

Quote:

Originally Posted by silv

I like it, too! You caught Carina nebula's pink glow! How beautiful is that!
Hope you are pleased with the first light of your mount.

If you can mark the position of the tripod legs on the ground once you are satisfied with your alignment - that makes it heaps easier the next time you set up. People sink bricks in the grass and mark the leg positions on the bricks, for example. You can get it quite accurate like this, soon, and quickly repeatable, too.

Enjoy!

Thanks silv, yeah, actually I am quite stoked about it. It does look pretty good for 'first light' with the mount. I will have to work out some markers in the ground as a temporary measure until I build a more permanent arrangement.

Quote:

Originally Posted by loki78

Yeah Russ I like it too especially for a first time. Can you tell us more about what equipment you used and camera settings etc.

I find it most helpful when seeing pictures to get all the details about what was used to take them also

I understand where you're coming from on that. It was a Canon EOS 450D with standard issue 18-35mm lens set at 18mm. 9 x 20sec subs at 1600 ISO f3.5, stacked in Deep Sky Stacker.

I need to learn more about 'darks' and 'flats' as well as processing and correct use of the histogram.

Quote:

Originally Posted by multiweb

Yeah that's cool but you need to keep your eyes on the histogram left and right prior to save to scaled TIFF or you'll clip your data.

Thanks Marc, so my initial steps are: I download the images using the standard Canon EOS Utility application and I view them with the 'Digital Photo Professional' application. At this point the are now on my PC in CR2 format. Is this where I need to do some processing prior to 'converting and saving' to a TIFF file?

Edit: Marc, I feel like a fool as I have just 'discovered' the Tool Palette in the 'Digital Photo Professional'

I'm assuming this is where I should be refining the histogram?

Visionoz (Bill) · #13 22-07-2012, 11:47 PM

Hi Russ

Congrats on a "first light" - at least you're quite spot on with that!

AFAIK you can open the RAW files directly in DSS - that's what I usually do anyway and only after stacking/processing do I actually save it as a TIFF from DSS and the edit it in Photoshop

YMMV
HTH
Cheers
Bill

Poita (Peter) · #14 23-07-2012, 09:40 AM

Download the latest beta firmware for the EQ6, it has a polar alignment routine built in that gets you more than close enough for widefield work, and it only takes a few minutes. It really works well.

Beautiful photo.

Russ59 · #15 01-08-2012, 09:26 PM

Thanks Bill, I've been a bit busy with work (or trying to find some!) so I will look at the RAW facility in DSS this weekend. This may improve my images for sure.

Peter, thanks for the info on the firmware. While I am a little hesitant about messing up the brand new/used once mount, I have downloaded the firmware and will build up the confidence to tackle it very soon.

Stephen, thanks for the encouragement.

A general question... I am take "subs" - normal images, and there are other shots called "flats" and "darks" I guess I'm going to have to learn about them one day because they seem to be an inseparable part of DSO imaging. Somwhere recently I'm sure I read a post here on IIS discussing the difference and methods? Can anyone direct me to a good dummy's guide to subs/flats/darks - just to get my head around the concepts in advance?

Cheers,
Russ