Veil Nebula

I am not sure if it is being ambitious or stupid. I ought to use a filter (OIII or UHC I think ?) plus lots of long exposures, but hey, why wait just because I don't have the equipment? This is based on 7 x 90 second exposures (there were going to be 20 but the clouds did for 3 and I need to take into account the tie it takes the camera to process the dark - which accounts for the other 10).

Anyway, camera settings as per last post ( but now I need to adjust the intervalometer settings). Veil was bang on after synching on Sadr:

A New World

Based on feedback from Stargazers Lounge and last nights ( brief, cloudy) experience,  a new world of setting up the GEM  is on my horizon:

1. Mount and tripod taken outside a couple of hours/hour before observing.
2. Telescope attached, collimated, balanced ( mirror very slightly heavy).
3. Polar scope used to align telescope to celestial north (aided by app on smart phone, showing where Polaris should be on a reticule; also use the same app to set time/date).
4. Using eyepiece, two star alignment carried out ( using Arcturus and Mizar ).
5. Add two (or three?) calibration stars; Deneb, Altair and Caph; again, it offers a limited list.

(Now use the Polar Align routine in Nexstar+; last night the telescope used Deneb; it was almost dead centre anyway, so maybe Polar Scope is good enough?)

7. I now replace the eyepiece with my Revelation 2" Barlow and Nikon D5300;  Bahtinov mask in place and last night I used Deneb to focus the telescope. 
8. Skew to a star close to the DSO I am after and use SYNC. Et voila, DSO will then be dead centre on GoTo.



Camera Settings

Going to try:
ISO  1600 - its noisy, but 800 doesn't seem sensitive enough for low surface brightness objects like galaxies.

Long Exposure Noise Reduction ON - and I will not take darks since the camera will do this AFTER EVERY LIGHT SUB automatically then process the raw using the in camera dark.

High ISO NR OFF

Exposures of 60 seconds seem easily attainable, from my experience two nights ago ( but that was also using the Polar Align  in Nexstar+, 120 -180 seconds are also worth trying.

Hopefully its clear tonight!!


News!!
The 90 mm telescope rings have arrived, just waiting on the dovetail plate. These are really for the time when I have a Skywatcher 80 ED Apo, with a Skywatcher ST80 piggy backed for guiding., but I am going to try using  the Skywatcher ST80 itself for imaging. I think it's a fantastically good telescope for the money and TBH when I have looked at the Moon, Jupiter, Saturn and various stars, the chromatic aberration seems pretty minimal, hence the experiemnt.

Much Improved Tracking on the Celestron CG5-GT mount

A lovely clear night and my first chance to put into place my new set up 'routine' ( well, hopefully to become a routine!).

New Setting Up Routine

1. Mount and tripod taken outside a couple of hours/hour before observing.
2. Telescope attached, collimated, balanced ( mirror very slightly heavy).
3. Polar scope used to align telescope to celestial north (aided by app on smart phone, showing where Polaris should be on a reticule; also use the same app to set time/date).
4. Using eyepiece, two star alignment carried out ( using Arcturus and Mizar - seems to be a limited menu choice, I assume it is recommending suitable stars as opposed to any stars).
5. Add two (or three?) calibration stars; Deneb, Altair and Caph; again, it offers a limited list.
6. Now use the Polar Align routine in Nexstar+; last night the telescope used Deneb; it was almost dead centre anyway, so maybe Polar Scope is good enough?
7. I now replace the eyepiece with my Revelation 2" Barlow and Nikon D5300;  Bahtinov mask in place and last night I used Deneb to focus the telescope. I can just about see the three lines used to check focus but I took a photo to check:

8. And now a photo without the Bahtinov mask to see it in all its glory:

READY TO ROCK AND ROLL!!

At an estimate, it took maybe half and hour to set up ( my first time at trying everything in the list).


Targets

I really wanted to see what the effect of all the steps outlined above had on tracking ( still no guider I am afraid). I chose Messier 51 since it was high and is easy to see even on a relatively short exposure. It was not dead centre, but was lower left in the screen,  Slightly puzzling, since my normal set up of two star alignment plus two calibration stars ends up with object just about central. Anyway, after a few tentative adjustments I was able to take some pics:

10 x 90 second exposures

210 second exposure (!)

I have been toying with the idea of not bothering with darks and bias, but since I have not tested the effects of using/not using in the dreaded DSS, I decided to shoot some darks and bias. Later I will see the effects of with and without ( remembering this time that DSS does not like DNG files; I need to export as TIFF before loading into DSS. (I am probably going to look at AstroArt 5 since Olly Prentice recommends it).

uh oh.... clouds appearing. So, now change of plan. Instead of exploring why a filter is needed for a good shot of M16 The Eagle Nebula, I slewed the scope to Messier 32 and tried some long and not so long exposures...

Conclusions   from the night




Regarding Accuracy of GoTo and Field Of View
According to the BBC Sky at Night field of View calculator (200mm aperture, 1000mm focal length , 2x Barlow):

F ratio: f10        Focal Length: 2000mm     Field of view:40.54' x 26.92'      Resolution:0.57"/pixel

From the size of M51, this looks about right. So, using those figures, the GoTo accuracy is off by about 15' x 10'. I wonder if this is typical ? (I shall ask in Stargazers Lounge I think !).

PostScript: Use Sync on a nearby star....not sure about refocussing now (have to remove camera, find star, sync, attach camera, refocus...)

Useful book for finding Deep Sky Objects

Years ago when I was living in Cambridgeshire, I bought a copy of 'The Universe from your Backyard' by David J. Eicher. This was based on a series in Astronomy magazine in the 1980's. I have always found it a fascinating book. It is set out via constellation (more or less). There is a section for each of the major constellations and the main DSO's that can be seen. IT also gives you the best season for that particular constellation. As well as some photographs, there are sketches of the DSO's , all taken using telescopes of different apertures/type. All in all very useful.

Now that I have started to take my first wobbly steps in astrophotography, David Eicher's book  sets me a great challenge in that with my equipment plus my skill, I am working at a level of detail around that of the late 1970'/early 80's! I hope to see my progress.

Anyway, I decided I needed another book  ( can never have too many books!). So, via good old Amazon, I have order a copy of 'Observing Handbook and Catalogue of Deep-Sky Objects' by
 Christian B.Luginbuhl, It sounds good, has a good review and was only £7.48 plus about £3 postage for a hard back!! Seems to be a step up from David Eicher's book in that there are many more objects. This book was published in the 90's. So. now I have the two books ot use to find and compare DSO's with. When I can 'do better', I will have to buy a more modern book!

Awesome picture of the day:

Best yet of Pluto

A clear night!

First clear night in over a week. So, I decided to have a look at M13 Globular Cluster in Hercules, M57 Ring Nebula, M16 The Eagle Nebula, IC 4665 open cluster and NGC 6905 planetary nebula (Blue Flash Nebula) in Delphinus. Then, what the hell, a galaxy, NGC 5985 (Trio) in Draco!

Ok, so these were intentions. But, pretty much carried out. Here are the best:

Now, problems. First, cheap laser collimator decided to do the dying swan, so it took ages to get the reflector collimated, (light kept fading). Then, I was all set, I decided that the wobbles I had the last time I tried imaging were due to the scope being too well balanced. I tried un balancing it a little, but it made little difference. Reading up after, I think I am just trying to be too ambitious, now that I have the intervalometer that lets me SET but not take smoothly 3 minute exposures. The advice is to make the scope slightly mirror heavy, but get it balanced on the other axis. Then , 30 second exposures are about the limit without guiding.

So, shopping list is a Skywatcher 80ED Evostar plus QHY5 II guider! Need to save the pennies.

Trying to process the images is very frustrating. I keep on trying to use DSS but it is a sod. It does not seem ot like much in the way of images. Certainly it does not like DNG files. So, exporting out of Lightroom as TIFF seems to be better ( other wide DSS says there are no stars!). I still seem ot have more success mucking them up in Lightroom plus Photoshop than in DSS. Defintiely work in progress.

Things I have forgotten. I didn't     think  the mount had found the Eagle nebula, so only took the one shot, then went elsewhere. When I 'processed' ( = murdered) it in Lightroom, this is what I had ( the lower left is from Google for comparison!!!:

So, using a filter, taking several exposures, stopping the mount from trailing and I will be there with a decent picture!

Anyway, in future, note to self:

1. Buy a new collimator

2. Make sure scope is slightly mirror heavy

3. Find out how to use the Celestron Polar Align tool (makes a difference apparently, over just using a polarscope)

4. Add a third calibration star across the ecliptic from the other two.

5. Possibly take the mount apart and try hypertuning it ( = could wreck it though??)

M71 Globular Cluster in Hercules

Not the most ooooo-inspiring target, but I had not seen it before, let alone tried photographing it. Apparently its a really interesting globular cluster since it barely has the correct characteristics. IT has a shorted of RR Lyrae stars and not a lot of metals. So, for a long time it was thought to be an open cluster. After some photometric surveys, it was clear that this was a mere baby of a globular cluster, maybe only 9-10 billion years old, instead of more like 12,000,000,000 years old!

Read a really good account of this interesting Messier object here

So, notes on the night...

Balancing the telescope is definitely a good idea, likewise making sure the power lead stays attached.  also discovered that letting the intervalometer hang by the cable from the camera (while I was trying to do something else quickly) is not a good idea; it separates at the connector and then falls... luckily it still works.

The sky really is too bright, especially with the moon approaching full. So, the image looks very 'thin' compared to others on the Internet. It will be interesting to compare this image with some taken later in the summer when the skies are darker.

I think the telescope mount works best when the scope is aimed above 45 degrees from horizontal; I can take 210 second unguided exposures then, but when it was aimed at M71, at about 45 degrees, several of the 60 second subs showed either a bit of a trail or double (slippage?). I will explore this further.