First Lunar picture - told it was Rubbish

[farnet]

Hey,

As in the title, I had my first ever attempt at imaging the moon at the weekend, I have a Meade 8" LX90, and used a DMK41 directly connected to a fine tuner.

The image was taken at about 5:00pm so it was still light and I captured about 200 frames and used Registax6 to stack them.

No matter how careful I was I could not get the focus any better, and even though it not perfect I was quite proud of my first attempt (see link below)

A work colleague, looked at the picture and basically said that he could do better with a $5.00 webcam on his scope and I have to say it took the wind out of my sails somewhat. He suggested I remove the mirrors and clean them, and I must admit this was a second (or third) hand scope and looking down the tube I can see a cat hair on the back mirror, but after reading the forums everyone seems to be unified in the idea that you should never strip a Meade LX90 scope.

this is the setup, Ignore the EOS camera, that's for when I was playing with a solar filter on the Meade.

Any suggestions, have I got a duff scope? am a being stupid on the setup? or dos it need a clean....

and can I give my work colleague a punch?

Cheers

Farnet

[nytecam]

Luna looks fine to me but it's not your workmate that needs a punch but your pic eg more punch by increasing the contrast in any image software

[jackrussell0232]

At least you said a 'work colleague', not a 'friend', so this criticism is more understandable.

There's nothing wrong with your image at all. Ok, it isn't going to end up on a magazine cover, but you've captured a reasonable amount of detail.

As for the advice to strip and clean the LX90, this is almost certainly the worst advice I have ever heard. Practice more, especially the processing aspects, which you can do in daylight/cloud/etc.

Check your collimation and focus. But believe me, you could have birdmuck splashes over you corrector and hairs on the mirror and still get good images out of your scope. But you probably will look back at this image in a year and say 'ok, I can see how I could have done better'. Even the experts do this.

Keep at it.

[russellhq]

The image looks OK but I think it's suffering from the seeing conditions at 5pm when you captured it. Try taking another later in the evening or very early morning. Also, try using a nearby star and a Bahtinov mask to improve your focus if you're struggling.

[IanL]

Your biggest problem is lack of contrast in the image. You may be able to improve it slightly in that image by manipulating the histogram. If you don't have any other image processing software, try the GIMP (free), here:

http://www.gimp.org/

The commands you will want to start with are these ones:

http://docs.gimp.org...-auto-menu.html

You want to increase the contrast between the dark parts and the light parts, so play around and see what you can manage.

In reality though you will do much better shooting at night rather than daytime. For one thing the contrast will be much better so the background will be blacker and the

highlights will be whiter. Also bear in mind that accessories may introduce unwanted reflections which reduce contrast, especially on bright targets like the moon. You do not need the diagonal when imaging, so remove it and connect the camera directly to the back of the crayford. (I'd say remove the crayford as well, I have the same revelation type on my SCT and I suspect it doesn't help contrast, but it definitely helps accurate focussing so it is the lesser of two evils)

The other reason to shoot at night is that the seeing may be better, especially if you have a lot of local air currents from buildings and concrete/tarmac surfaces. These will reduce at night, and if you have the option try to shoot facing over an open area of grass rather than a hard surface or the roofline of nearby buildings.

You absolutely must let the LX90 cool down properly as well; there is no way it will be cool enough at 5:00pm and that will induce air currents inside the telescope tube which will distort the image. Trust me, this makes a massive difference on an 8" SCT. Put the scope outside as soon as the sun goes below the horizon, or your observing location goes in to shadow for the rest of the evening. You should wait at least an hour after dark, and two or three hours would be better if there are enough hours of darkness. (Bear in mind though that the scope may never reach equilibrium on some nights if the temperature keeps dropping, but you should wait at least an hour after dark in my experience).

Next, work on your focussing technique. You may find it easier to focus on a nearby star first, and then moving on to the moon itself. Look in to making/buying a Bhatinov or Y-Mask (search the forums) as this can help you nail the focus. Luckily focussing is not so hard on a long focal length scope like yours.

Finally a couple of words of advice about scope maintenance:

- Cleaning the scope is not something you should do unless you are 100% confident you know what you are doing, and that you have a serious problem. I have an LX10 which is pretty much the same OTA to the LX90. In about 15 years of owning itI have removed and cleaned the corrector once to remove a serious build up of dust and some kind of greasy accumulation from the air (due to having to store it unused for about 7 years in very poor conditions).

We're talking the back of a van with 'clean me' written in the dirt kind of dirty, not a few specks of dust and the odd finger mark (which would have no appreciable affect on your image). I also removed a dead spider from the side of the primary mirror and its web from the tube. I have never cleaned the primary mirror and wouldn't contemplate touching the secondary at all.

Bear in mind that these highly visible lumps of dirt and grease marks are so out of focus in your image that they have no appreciable effect on it. The most you should do is use a blower bulb to dislodge any dust that collects on the outside of the corrector.

- Collimation is important for an SCT. It is pretty easy to check whether you need to collimate or not, but it can be tricky to figure out how to collimate well as a beginner. For the best explanation of why you need to collimate, look here:

http://legault.perso....fr/collim.html

Here's a quick video on the principles of the process:

There are loads of articles on collimation, so do a bit of reading before you start; you may already have really good collimation, but if you haven't it is definitely worth the effort.

Once you get to the stacking stage of the process, this is the best tutorial for lunar images and the process I use (it covers Registax 5, similar principles can be used in 6):

http://www.astronomi.../bobspages.html

It takes about three times as long as a simple run through with the basic process, but you do get a better final result if you have a good input image. If you want to start making mosaics for a wider area, then stack each one of them individually and use something like Microsoft ICE to composite them together:

http://research.micr...groups/ivm/ICE/

You should be proud of your first attempt; it is far from perfect, but you have learned a few things from it and that is what this game is all about. Doesn't matter how good your images are, you always spot something that you could do better next time! Keep trying, and in 12 months time you will look back and be amazed at how much you have improved.

Here's an example of what I managed with a similar setup (my ancient LX10 and a Canon 500D DSLR):

(Full resolution here: http://www.astrobin..../8617/?mod=none)

[neilhooper]

My first and only attempt so far is this;

http://sdrv.ms/10qbJEz

I did it on an impulse and although I had done a very quick bit of reading, and I mean quick, I didn't really know what I was doing, how to set exposure etc.

I know it's over exposed but I didn't know at the time that I should have it a bit darker than I wanted and then brighten it up after. Also I took 200 frames thinking that would be enough and have since discovered that I should have really taken 2000 ....

Hopefully my next attempt will be better.

- Neil

[Superdavo]

Luna looks fine to me but it's not your workmate that needs a punch but your pic eg more punch by increasing the contrast in any image software

Yeah, increasing the contrast may help to remove the greyness in the background. That may be caused by dust in the scope, but I don't know. It's certainly a nice shot, so i'd tell your workmate off!

[northcanadian]

Great start!

I got into this great hobby about 5 years ago and found/still finding some daunting learning curves (especially so being an old guy) We amateur imagers are all going individually where no man's gone before. We sometimes are subjected to the odd highly critical opinions but not here...I have learned so much from SGL members on this site...always positive and constructive.

Picture this.....Michaelangelo high up on the scaffold doing his Sistine chapel masterwork.....while a well-intentioned but unqualified oserver (far below the scaffold...looking up) shouts up an opinion....."I think the robe on that guy is too blue!"

Cheers

Roger

[russellhq]

Farnet,

I opened up your pic in photoshop and simply selected "Auto contrast" and this is the result:

You can take it further if you wish.

[michael.h.f.wilkinson]

Did you apply any wavelet processing in Registax? That can sharpen things up quite a bit (apart from the contrast stretch)

[bish]

It's a damn site better than my efforts! I don't know what your work colleague would have to say to me

[Spacecadet2010]

Question from 'noob':

(firstly your colleague should give credit where it's due, this is an excellent first attempt, and I would be over the moon (pun intended) at this. Most of my attempts so far have resulted in big blurry blobs.)

Here's my question; why so many images? Presumably with such a big bright image, you should be able to catch enough light with fewer short exposures. Surely the only reason to stack would be for images where not enough light is captured and extended exposure times would result in blurry images?

i would think the poor contrast was probably due to the time of day the image was taken, and therefore you wouldn't be able to do better with a cheap webcam.

Any useful comments I might have about post processing have been covered. I like Photoshop elements if that help which retails at about £60, though I think you can get older versions for less. Until recently I was using version 5 which still has lots of functionality.

[michael.h.f.wilkinson]

Question from 'noob':

(firstly your colleague should give credit where it's due, this is an excellent first attempt, and I would be over the moon (pun intended) at this. Most of my attempts so far have resulted in big blurry blobs.)

Here's my question; why so many images? Presumably with such a big bright image, you should be able to catch enough light with fewer short exposures. Surely the only reason to stack would be for images where not enough light is captured and extended exposure times would result in blurry images?

i would think the poor contrast was probably due to the time of day the image was taken, and therefore you wouldn't be able to do better with a cheap webcam.

Any useful comments I might have about post processing have been covered. I like Photoshop elements if that help which retails at about £60, though I think you can get older versions for less. Until recently I was using version 5 which still has lots of functionality.

Stacking many images helps neutralize seeing effects. Getting a single shot in those short moments of good seeing is hard. Taking a stream and letting the software stack a certain percentage of the best is almost invariably better.

[Jaykay495]

As already said, you're colleague clearly has a bit of the green-eyed monster.

you're pic is really nice, and just needs the contrast between dark and light dealing with to sharpen up the detail captured.

i'm starting off down a similar road to you. Every day is a school day

[IanL]

Here's my question; why so many images?

This is a form of 'Lucky Imaging' (http://en.wikipedia.org/wiki/Lucky_imaging). We take hundreds, or even thousands, of short exposures to 'freeze' the seeing and we quite literally rely on luck that some small percentage of them will not be blurred. Software (such as Registax) sorts through the images and picks the least blurred ones and averages them together (well the maths is a bit more complicated, and it picks the best bits of each image).

A good example of how and why here: http://www.ast.cam.ac.uk/research/instrumentation.surveys.and.projects/lucky.imaging/latest.results/amateur.lucky.imaging

[Atlas]

Your image is very nice, The only thing needed is a play with the contrast and post processing touches that folks have stated. Your on the right track, and never let the opinion of anyone discourage you from your hobby.

[Stargazer33]

As everyone else here is saying, it's a very good first attempt. Yes some things can be improved - contrast, sharpness etc. But taking luna shots during the day is not easy. You have made a very good start. If we were perfect at everything we did at the first attempt, life would be boring!

Be happy with your first go and proud of what you have achieved. Read up about luna imaging and ask questions as you have done here and, weather permitting, practice; practice; practice.

It might not be a good idea to punch your work colleague, but you could flip him the bird!

[todd8137]

Its a great firtst. Image its a bit soft looking and not sharp as you would like but looking good to me keep it up and do not give up

par