My first ever image of Mars - very pleased!

[x6gas]

OK, so what the title says basically!

I actually set up tonight to do some deep-sky, but the clouds rolled in... I decided to leave the scope set up and later on managed to capture a couple of AVIs of Mars between the clouds.

For fear of missing the opportunity, I didn't collimate the scope (and I haven't used my 11HD for ages so not sure what the collimation is like now), but I'm pleased with the result.

Anyway, best 800 frames captured using QHY IMG0H, 11HD on CGEM DX, with a quick stack and process in Registax

Hope you like it!

mars120229.tif

mars120229 cropped.tif

[Moonshane]

really nice image. this is pretty much as I was seeing it tonight through my 6" f5 at about 200x.

[mike.brightmore]

I really like it - just as it appeared in my CPC 1100.

[Clayton]

Nice going

[x6gas]

Thanks Moonshane, Mike and Rob.

The seeing wasn't that bad, probably better than average from my location, but the cloud was problematic. This was also a very quick stack and wavelet process in R6, so I may have a go at doing better tonight...

I have a powermate being delivered today which is sure to mean that I won't get another chance at Mars this opposition! That's why I was so keen to grab whatever I could last night though it was actually getting clearer when I packed up at around 11 so in the end I regretted not collimating and taking the usual care over focus (just did the best I could on the planet rather than using a mask on a nearby star...)

Still, as I say, pleased all things considered.

Thanks so much for the kind comments; means a lot.

[Sam]

That's a very good Mars image. Nicely done!

[Dave]

Nice one.

[Zul]

Very nice image!

[DrRobin]

Hi,

Nice image. Using similar equipment to you I took this one of Mars last night. I used a C1100 Edge with DFK31 and a 2x barlow. It is only the second time I have used this scope, still trying to get to grips with it.

I had a go at Jupiter before and whilst like Mars it was in focus, the detail didn't look that good. It might have been the seeing, but could a collimation error produce that?

I didn't try Mars without the 2x barlow, I did try Jupiter but haven't processed the results.

[x6gas]

Hi Robin,

I don't think I have my scope perfectly collimated yet (haven't had too many nights under the stars with my 11HD either!) but I am told that collimation is as important with SCTs as for Newts, at least in order to pul out fine detail in planets.

What frame rate are you managing with your DFK31? The faster the better when the seeing's not great, I find.

What stacking and processing software are using? I use Registax 6, stacking 1000 frames of a 2000 frame avi.

The image below from last night is a bit noisy and over cooked, but used the following wavelet settings in Registax:

Layer : Denoise : Sharpen : Preview

1 : 0.00 : 0.110 : 76.1

2 : 0.20 : 0.100 : 71.8

3 : 0.20 : 0.250 : 85.9

4 : 0.00 : 0.100 : 76.1

5 : 0.00 : 0.100 : 44.7

6 : 0.00 : 0.100 : 61.3

I am still playing with wavelet settings, but would be interested to see what you get with a similar process...

23-21-27-832.tif

[DrRobin]

Hi,

From memory I was getting about 30 fps with my DFK31. I took around 2500 images and stacked about 1000 in Registax 6, using similar settings as you for the wavelets.

I actually think it is collimation. I have only used my C11HD twice and now realise that I have never checked the collimation, a bit of a mistake. I looked it up in the manual and it looks like these SCTs are sensitive to collimation, so next task.

My other scope is a Quattro 8" F4 and they are supposed to be collimated very frequently, only thing is mine never seems to drift off. It is however, kept at a reasonably constant temperature (mostly cold).

[x6gas]

Looks like collimation to me too.

I hear the quattros are pretty sensitive to collimation so you clearly know the score, but I found this Collimation guide to be really useful.

The collimation screws on my HD11 were made of something which has approximately the same consistency as cream cheese. I replaced mine with some A4 stainless steel knurled thumb knobs - see this thread for details of cheaper alternatives to http://stargazerslounge.com/discussions-scopes-whole-setups/166162-bobs-knobs.html - highly recommended and under five quid.

Cheers.

[si@nite]

Thats a nice shot well done. SIMON.

[DrRobin]

Hi,

Thanks for the link to the collimation guide, I checked out a couple today, including one using a laser and eyepiece with a target on the wall. I think I will have a go and see with a few methods and find which one works best.

Thanks for the link about A2A4 they look good. I know what you mean about cream cheese, it's a shame when a scope costs so much they can't put some decent screws on it.

I am thinking about a Lepus 0.7 focal reducer for the C11HD. I saw that the Celestron will be available soon, but I expect it to cost around double the Lepus. Don't suppose you have used one have you?

To be honest I don't collimate my Quattro too often and it doesn't drift very much either. It is a Carbon tube and I keep it at a reasonably constant temperature, so perhaps that helps. I like things like that, you know just works without too much fiddling.

It's reasonably clear here tonight, but too much moon and a bit windy so have spent the night testing a guidescope made with a DFK31 and a 50mm finder, works very well. More than I can say for my pulse guider, which keeps resetting on the USB, either a rethink like EQMOD or fix it.

And then trying to get a focal reducer working on my Atik and Quattro, I have run out of back focus. I have tried every adapter in my collection, but still can't get enough inward travel to get focus. Just after packing up, I have found the solution, mount the Atik directly on to the scope with T2 thread and then pop the focal reducer inside the focuser and hold in place with the eyepiece screws. That way I can set the distance from sensor to focal reducer and adjust the magnification. Another solution that's just going to work with minimum hassle.

[x6gas]

I am thinking about a Lepus 0.7 focal reducer for the C11HD. I saw that the Celestron will be available soon, but I expect it to cost around double the Lepus. Don't suppose you have used one have you?

Just had one delivered from Teleskop Service but haven't had the chance to use it yet... basically been spending any time under clear skies on Mars but I am looking forward to testing the Optec. will let you know how I get on...

[DrRobin]

Hi,

Thought someone might have one. I had a look to see who sells them in the UK, not very many if anyone so contacted Optec directly. They will/can sell to the UK and as I want a custom adapter (extension tube), I understand these are made by Optec in any case, to use it with an OAG it made sense to get it directly. Price is pretty good as well $ for £/Euro, but then shipping is likely to be more and I might get stung for import duty.

I would be really interested to find out how well it works? Mrs DrRobin will go ballistic if I buy one and stratospheric if I subsequently don't use it.

My pulse guider is sitting on my desk at work, lunch time job is to get it in the workshop and fix it or chuck it and buy a GPUSB or get EQMOD working.

Robin

[Space Cowboy]

Nice images.

Auto RGB balance in Registax would make a big difference making the ice cap and cloud detail white which brings out the detail a lot more without needing to over sharpen (lowering gamma and raising white also helps contrast).

[DrRobin]

Hi,

My pulse guider is now working correctly. It was a combination of processor watchdog set and a wrong connection on one of the pulse outputs. Typical total cloud cover here and there is a good chance of an Aurora tonight!

A quick question when using a pulse guider, I am assuming that I turn tracking off, otherwise the two might fight against each other?

I will give Mars another go in Registax, thanks Stuart.

Next job, collimate my C11 and I have a pier turning up sometime soon so I will have to get my concrete base drilled and bolts inserted.

Then it's back to Mars, Jupiter in a months time and some more DSOs.

[x6gas]

Nice images.

Auto RGB balance in Registax would make a big difference making the ice cap and cloud detail white which brings out the detail a lot more without needing to over sharpen (lowering gamma and raising white also helps contrast).

Thanks for the advice Stuart and a good suggestion. Before and after shots below and I think it is an improvement. These are at about f/20 (with an ultima barlow). I have some at about f/50 with a 5x PowerMate but I am really struggling to get anything worth posting out of the process... Imaging at f/50 ain't as easy as Neil makes it look!

[DrRobin]

Hi x6gas,

I am back looking at the C11HD and want to ask your advice about distance from the OTA flange and the ccd. I know that the distance is 146mm from back of the flange to the ccd, but what happens when you put a Barlow in?

Do you adjust the distance of the barlow and ccd to get focus keeping the focus knob in the same place or do you adjust the focus knob and hope the distance is correct?

I have read that coma is a real problem if the distance isn't right and I think half of my problem is not collimation, but incorrect distance.

[x6gas]

I'm not sure I completely understand what you mean...

I know that the backfocus distance is important when using field flatteners and focal reducers but I am not aware of any specific backfocus distance for the C11HD in its native form... there is an optical element that provides correction (and this is one of the differences between the C11 and the HD version) so it could be so. Can I ask where you got this info from?

Or are you talking about the Optec focal reducer?

Cheers, Ian

[DrRobin]

Hi Ian,

The distance of 146mm from flange to ccd is mentioned in several places, but there is an app note on Celestron's website about it, see below:

Will I be able to use my standard Celestron SCT T-adapter 93633-A to attach my SLR camera to the EdgeHD?

Unlike a newt with one parabolic mirror and a flat, there is only one focus position but an SCT (especially one with a corrector plate) could have more than one point that will appear to be in focus at the centre, but not working correctly.

Imagine if the distance between primary and secondary was too short, it might be compensated for at least partially by lengthening the secondary to sensor distance, but I doubt that light across the whole of the primary would be focused in the same place.

I am going to have a go at setting the distance correctly to see how much it improves performance, now where is that ruler?

[x6gas]

Blimey - well that's a new one on me!

Thanks for the info Robin. My OAG/filter wheel/CCD adds just shy of 63mm and with a nose piece and diagonal I reckon I am at about the right distance. I haven't done much DSO stuff with the 11HD, and haven't noticed any issues but this is worth knowing as I want to lose the diagonal from the imaging train... so clearly I need to give some thought to this.

I do have the right gap for the optec reducer and that screws right on to the big SC thread...

Thanks again for raising, Ian.

[DrRobin]

Hi Ian,

In the same section as the 146mm optimum distance I also found this article, which says for small sensor CCDs the distance is not that critical.

I have a small-chip CCD camera or APS-C format DSLR or webcam with an adapter that isn?t made for the EdgeHD. What problems will I have with image quality using this system since it?s not the optimum spacing size?

I am still going to try for 146mm, the less variables and deviation from the ideal the more chance I have of getting the best out ofthe scope.

[mindburner]

very nice, I'm glad the new kit is working out well