A corner of The Moon

[PhotoGav]

This is the first light with my new Orion StarShoot Solar System Color Imager IV. It's probably not a camera that I would have chosen, but the Sky At Night Magazine kindly sent it to me. So, I thought I had better at least try it out and the moon is quite big out there at the moment. I plugged it into my Celestron EdgeHD 800 and managed this:

200 of 400 frames, processed in PiPP, stacked in AS!2, tweaked in PS. It took aaaaages in AS!2.

So, the main question is "what are those little squares?!". They seem to be coming from the AS!2 processing and are less evident at nearer to 100% size. I must be doing something wrong with the processing, but I wonder what...?

Apart from that, I'm quite happy with this effort. It could be crisper, but that might be down to seeing or focussing or just quality of the camera?

[PhotoGav]

Just tried the stacking in Registax6 followed by the same sharpening tweaks in PS and managed this:

it seems to be quite a bit better.

[Blazar]

Gav, nice work.

Don't know what that artefact is to be honest, but it is very structured, so must be a processing induced item. You stacked 50% of the frames which I guess means you had a good quality graph. I usually tend to stick to around anything with a 75% or better quality rating in ASI2, everything else is ignored. That way you don't artificially soften the image with poor frame data.

Depending on when you took the capture it might be you where going through quite a lot of the atmosphere. I had some 'soft' images a while back. Either that or focusing I guess.

I was out last night as well...bleedin freezing. Got to the point I was having trouble manipulating my right hand for focus!

Regards

[PhotoGav]

Steve, thank you for your response. I was just admiring your two recent posts, Highs & Lows and Vallis, thinking that is the kind of quality I would like to achieve. We have the same scope, so it should be possible for me...

I'm becoming sure that the artefacts are just from over sharpening the image. Interesting about only stacking frames that meet a high quality rating - I will definitely give that a try.

Do you think that I can blame the quality of the camera too, or should it be capable of producing a better image? I see that you are using a ZWO 120MM camera, that seems to be up there as the best piece of kit for solar system stuff. Certainly the good images I see on here seem to be made using a ZWO camera. Is yours a mono version? This is probably edging towards a whole new thread, but, is mono the way forwards for planetary as it is for DSO (my main area so far)? How do you go about capturing the data for something like Jupiter which is spinning relatively quickly - do the colour channels end up not quite registering if you are not quick enough?!

[Blazar]

Hi Gav,

Cheers for the likes... It should be easily within your grasp to get the same results. These edge scopes are brilliant...though I have upgraded my focuser to a Moonlite crayford (I know could not help myself). the extra ability to not only focus roughly on the scope focuser, but to then have the 8:1 smooth focus on the Moonlite really has helped. Not saying you should rush out and get one, but something worth considering....though once bought, if you upgraded the scope to a larger SCT it probably won't fit...

Think the camera will produce a good image. the pixel size (3.6microns) is smaller than the ZWO, though not sure how big the sensor is, though I would imagine the size is pretty much the same as well. The ZWO does have quite a good control on noise from what I hear. My One is the mono yes. So the naming convention for the cameras tells you the type (so in my case its a ASI120MM-S. They come in two variants the MC (one shot colour), or the MM (Mono). the -s is the newest variant, and is pretty darn amazing. Mono is deaf the way forward IMO (though it will mean filter & filter wheels etc if you want to produce a colour image)..though with our weather you could not have enough time to get a complete set of captures. Mono is usually more sensitive than OSC.

Funnily enough I did have a crack at Jupiter last night. Bit silly really as it was quite low (so looking through a lot more atmosphere), and I had not checked the maximum exposure time. Jupiter rotates quite quickly, so to avoid having to de-rotate the image, you need to work out how long your avi's should last (or at least thats what I do). So to do that you need to know certain details about jupiter at the time you are going to capture it (so stellarium for example can give you the apparent diameter in arc seconds). you then do a bit of maths (or my spreadsheet does), and it spits out a maximum time in seconds to image it for (with de-rotating the images).......but I forgot to do that last night 8-)

The math I use is this: T [min] = resolution of the instrument [arcsec] / (Pi * apparent diameter of the planet [arcsc] / rotation period of the planet [min])

so today it would be 158 second maximum.

Just wondering if the blockiness in the first image was actually under sampling.....

[Blazar]

Gav,

Doing a bit of reading, and the old NexImage used to do compression on anything above a set FPS.(30ish)...and you don't see this in the avi, but horrendous in post processing....perhaps this Orion also does something along the same lines?

Regards

[PhotoGav]

Steve, thank you for the various answers and thoughts. No idea about the compression that's going on in the camera. If that is the case, it's another good reason to get a better camera!

Very interested to hear about your focuser upgrade. I have looked at the options - the crayford on the back or the starlight instruments feather touch to replace the standard focuser. I was under the impression that a crayford messed with the internal flattener and was generally not a good option with the edge series scopes. I actually ordered the starlight one yesterday from FLO... Expected delivery tomorrow! Hopefully it will help the focus significantly.