NGC4565 - Needle Galaxy

Paramount · Post by **Paramount** » Fri Apr 29, 2011 6:23 pm

Hi
This is my first posting here as I have only just joined. I live in the UK and although I enjoy every aspect of astronomy my passion is astro-imaging as it is the only way to show the otherwise hidden beauty that is out there in the vast blackness of space. I live in a light polluted area and partly because of this I specialise in "multi-spectral" or "narrow band imaging" of the emission nebulae and planetary nebulae. The equipment that I use is in my signature and because of the nature of the subjects that I image and the filters that I use the exposure times are very long, in the region of 30 minutes each. Here are a few examples of some images that I took last year

IC1396

NGC6888

Veil Nebula

Heart Nebula

Cederblad214

Back to my most recent image, it is now galaxy and star cluster season as there is very little in the way of emission nebula to do where I live.
I had a clear night on Wednesday of this week and managed to shoot just over 5 hours of NGC4565 in 10 minute subs before it dipped behind a tree at just after 4am. It was taken with the FSQ106ED at f5 and Starlight Xpress SXVF H9 on a Paramount ME. Auto guiding was via a lodestar and OAG. Exposures are 12x10 minutes each for red and blue and 7x10 minutes for green. Hopefully I will be able to get a bit more data and some luminance on the next clear night. I did an unguided monochrome shot of this 2 years ago with the BRC-250 and Starlight Xpress H36 using 4 minute subs. This can be seen fo comparison on the galaxy page in the image gallery of my website http://www.imagingtheheavens.co.uk
The full size high resolution image of this can be seen at http://www.pbase.com/imaging_the_heaven ... 5/original
Thanks for looking
Best wishes
Gordon

Post by **rcj** » Fri Apr 29, 2011 6:40 pm

those are spectacular imagery, Gordon! love the SHO shots.

timatworksg · Post by **timatworksg** » Fri Apr 29, 2011 7:14 pm

Yes...spectacular imagery of the Emissions! SHO shots are lovely!
Welcome aboard here Gordon! Hope to see more!!

cloud_cover · Post by **cloud_cover** » Fri Apr 29, 2011 7:21 pm

Ooooooooooooooooooooo! Very Pretty!

Clifford60 · Post by **Clifford60** » Sat Apr 30, 2011 5:25 am

Wow

, fantastic pictures. You have a great website with a great collection of the night heaven taken too [smilie=admire2.gif]

kensou · Post by **kensou** » Sat Apr 30, 2011 11:01 am

wow... so long the exposures.. i wonder whats ur equipments are

Paramount · Post by **Paramount** » Sat Apr 30, 2011 11:10 am

kensou wrote:wow... so long the exposures.. i wonder whats ur equipments are

Hi
The equipment list is in my signature at the bottom of the post. Three things are required for long exposures
1. A well balanced system
2. Accurate polar alignment
3. Good auto guiding
Best wishes
Gordon

timatworksg · Post by **timatworksg** » Sat Apr 30, 2011 11:23 am

Agree with point number 1. A well balance system is a factor in AP. Improves the Pointing accuracy and tracking of everything else. Having the counterweights nearer the scope, balances the system better than extending or securing the weights way down the shaft. Doing so increases the strain on the RA axis and increases the probability of balance shift when the RA axis is at certain rotational positions. Helps when both scope and weights are almost at equal distance apart from it's fulcrum. Get this right on both RA/DEC and Autoguiding works ten fold!! You can shoot for hours with no drift!

Hardest prob is...what does one do when taking long exposures?..lol! Apart from sleeping that is!

Once again....Great shots Gordon. Can't help but keep looking at these!

Paramount · Post by **Paramount** » Sat Apr 30, 2011 11:53 am

timatworksg wrote:Agree with point number 1. A well balance system is a factor in AP. Improves the Pointing accuracy and tracking of everything else. Having the counterweights nearer the scope, balances the system better than extending or securing the weights way down the shaft. Doing so increases the strain on the RA axis and increases the probability of balance shift when the RA axis is at certain rotational positions. Helps when both scope and weights are almost at equal distance apart from it's fulcrum. Get this right on both RA/DEC and Autoguiding works ten fold!! You can shoot for hours with no drift!

Hardest prob is...what does one do when taking long exposures?..lol! Apart from sleeping that is!

Once again....Great shots Gordon. Can't help but keep looking at these!

Good points, however, the most important essential for long exposure astro photography is the polar alignment especially with large fields of view. Even a poorly polar aligned mount can track accurately, but only the stars in the middle of the image will have no trailing while the ones at the outside will start to rotate, otherwise known as field rotation which occurs in poorly aligned systems. Typically for the emission line images that I take with sub frames of 30 minutes+ my polar alignment is within about 5 arc seconds of the true celestial pole. I use TPoint mapping (which also increases the pointing accuracy) from within The Sky 6 software which works with the Paramount ME in order to achieve this accuracy. Incidentally the Paramount will carry on tracking accurately without batting an eyelid even if it is a few kilos out of balance
Best wishes
Gordon

timatworksg · Post by **timatworksg** » Sat Apr 30, 2011 12:45 pm

Yes good initial polar alignment is very critical. Autoguiding is an added enhancement to this...lol!

Have read rave reviews of T-Point and the Paramount ME. The Robo can take the abuse and still point accurately for a long time once taken through TPoint's solving methods. And TPoint alone can solve many mounts!
Love your set up for AP especially the FSQ...lol.

Cheers
Tim