bobro

Great Crescent with good full body to it Nige. Can you tell me why the 2 exposure values (it's not a HDR target I think)? Thanks, Bob.

Cracking image Nige! Great detail - setup must be well configured and very stable.

For a change to the Veil, IC1396 including the Elephant's Trunk. I wasn't too sure quite where the trunk was nor how large it is and 6 minute subs didn't show any nebulosity (not a very clear night), but did manage to capture a little of it in 5 subs. Certainly worth a revisit, probably with longer subs.

Ditto!

Well, Art gets the prize for predicting the level of improvement the CG5 tripod would make to guiding of my EQ2 - none! (see new graph below) Not surprising really as the EQ2 and ecomony motor drive are pushing things a bit. So it's back in the box for the CG5 for now (waiting to meet up with an EQ3 mount) as the old tripod is easier to carry around. Managed to get another 2 (yes just 2, - don't ask!) subs to add to the previous 3 on the Veil. Tried out StarTools binning/noise reduction - makes a good improvement.

Thanks Neil, however you may have a change of view when you see a fairly typical guide graph below (though DEC is better now after a bit of re-greasing). As the setup isn't doing the OTA justice, I've acquired a CG-5 tripod. With a little hacksaw work the EQ2 should fit on it. (I promise part of an upgrade plan to include an EQ3 - don't chuck me out please! ) Now my turn to set a challenge to you guys - can you predict what improvement (if any) the new tripod will make? The old tripod is a 1.25" steel tube as supplied with the Meade 130EQ. Remember the RA motor is just a simple dc motor with a gearbox.

I haven't got an EQ2 Challenge to go to...sob....sob . Besides, these guys are really helpful!

Is AP a bit like fishing - about the one that got away? Beautiful night - very clear, darkest skies for a long time, target overhead, windy but not affecting the scope. Only one problem of course - low clouds! Only managed 3 subs @ 240sec on the Veil Nebula.

DEC direct drive perhaps? Looking forward to some super guided images to come!

Lots of posts on StarTools recently. I now have a copy of StarTools but haven't dived in yet (tried briefly but not enough time to quite get it). Hope I can improve on an attempt at reprocessing my recent M27 in GIMP!

Another test to find out whether the focuser is true is to rack the focuser totally inwards and take a flat. Then rack the focuser outwards and take another flat. If, when the 2 flats are stretched, the bright spot is in the same place then the focuser is true. Nige - what camera problem could cause this? A mis-aligned sensor?

Great to see you getting flats to work now - really makes a big difference to your images! I wonder if your scope is a litttle out of collimation? A stretched version of the flat should be fairly symmetrical in brightness, whereas yours is offset. This can be seen in coma in the stars in the darker regions of the first image without flats. For comparison here are stretched flats for our scopes. No big deal though...

Hi Peter, You did much better than my attempt on the Veil last night - reflections inside my scope due to the Moon I think. Perhaps a cowl will help. Clouds too! If you're not already doing this, before saving the image in DSS set the Saturation shift (Saturation tab) to about 20% before aligning the RGB histogram peaks (RGB/K Levels tab). Bob

Probably depends on how an image is subsequently processed e.g. I normally use Kappa Sigma clipping in DSS which (I understand) needs a consistent background level in order to operate correctly. Hopefully someone will be able to explain a bit more about Background Calibration......

Probably a good idea to ensure DSS stacking has 'Per Channel Background Calibration' set to 'Yes' to ensure a consistent sky background level before stacking.

Just my sort of image! Sometimes images can seem to be a bit over processed (easy to do) but this one has a lovely natural colour progression to it that is easy on the eye. Lovely and well done!

Another Stub sub challenge to us all?

Here's Mr Pelican looking a bit less blue - tried out (in GIMP) decomposing an image to separate RGB layers for the first time, allowing the blue haze to be adjusted out. Quite a useful feature.

Peter's flat shows as taken at ISO3200 and 1/4096 sec exposure. I guess the speed is as fast as the camera will go. Perhaps the shutter is a bit sticky at this fast speed. In any case it looks a bit overexposed - a good plan is to have the histogram around the mid point. Flats don't need to be taken at the same ISO as images (I previously thought flats needed to be taken at the same ISO as images but was corrected by someone with more knowledge and did some tests that showed flats worked irrespective of the ISO used). So I suggest reducing the shutter speed and ISO if necessary in order to obtain flats with roughly a mid point on the histogram.

Thanks guys for the images of the Crescent Nebula. It's certainly not the easiest subject! If I try it I think a test with a good long exposure is called for - perhaps 10-12 minutes and preferably with a darker sky.

Neil - could you post the standard DSLR image for comparison? Thanks. Bob

I like the sharpness and clarity of the image Mikey. Can you tell me what subs were taken? (It helps me evaluate the image/target and also decide if I should have a go at it.) Thanks Bob