Below are the first light experiments with my new RC8.
These images were taken with the Astrophysics 0.67x reducer giving a FL of 1088mm @ f5.36
Orion mini 'finder-guider' used for autoguiding, stock GSO focuser replaced with a Feather Touch Light Weight model.
I figure all eyes will be drawn to the M42 image with its obvious blue reflections - looks like the baffle flocking will be on the cards or I wonder if it's coming from the reducer?? May have to experiment before committing to a mod.
From that same image you can see my dodgy collimation too - and forgive the poor core mask too
Still, I'm quite happy with progress so far and that the HEQ5 Pro can cope with the weight of the rig.
Cant give you any advice Doug, but a fine effort indeed mate, I'm sure we can expect some awesome imaging from you in the future, well done indeed.
Leon
Cheers Leon - I hope so!
Quote:
Originally Posted by RobF
Congrats on such fine images so early on Doug. How much does the rig weigh approx (have you comments re heq5 tracking in mind)?
Thanks Rob - probably weighs around 9kg. Mount seems to handle the weight. On-axis stars are nice and round on my 5 min subs, start to look a bit eggy at the edges at 10 mins though. I think the rig will be susceptible to breezes too!
Hey Doug that M42 looks really promising. I am having a similar issue with my SN 8" and I think it's better than the FLT but I was quite annoyed and went back to the FLT. I need to spend a little time with my SN to get to know its issues better in these situations.
I am finding the MPCC is interfering so may this is the reducer?? Not sure but maybe someone else more qualified than me than help you.
Hey Doug that M42 looks really promising. I am having a similar issue with my SN 8" and I think it's better than the FLT but I was quite annoyed and went back to the FLT. I need to spend a little time with my SN to get to know its issues better in these situations.
I am finding the MPCC is interfering so may this is the reducer?? Not sure but maybe someone else more qualified than me than help you.
Darrin...
Cheers Darrin - Next clear night I'll try imaging the same region without the reducer at FL=1624mm and see if the reflections persist. I bought some flocking material but would rather not open up the beastie if I don't have to!
Doug
I'm running a GSO RC10 with the Astro-Physics 27TVPH reducer and haven't noticed any issues with reflections, but I haven't imaged anything that bright with it yet. If the skies ever clear here I'll point it at M42 and see what happens.
Great effort Doug , as for the reflection I would suspect the fd havent used mine yet but I have done 15min subs with the RC10 and have no reflections at all.
Doug i have the RC8 and get a reflection from Alnitak when imaging the HH without a reducer so it might well be worth it to start flocking the scope.
Go here for the flocking --->> http://paulhaese.net/gsobaffleflocking.html compliments of Paul Haese
Thanks Gents - the flocking material is on its way.
Had a look at Paul's flocking mod. Looks reasonably easy but are there any nasty little surprises waiting for me with this mod?
Cheers
Doug
congratulations for the first light ... very very nice.
For the reflections ... coming from the AP CCDT67 reducer in combination with GSO ... i have the same problem with the 10" depend on position of out of field big stars... You may mitigate it decreasing the reduction factor to F6.5 calculating the right spacer with the AP formula.
congratulations for the first light ... very very nice.
For the reflections ... coming from the AP CCDT67 reducer in combination with GSO ... i have the same problem with the 10" depend on position of out of field big stars... You may mitigate it decreasing the reduction factor to F6.5 calculating the right spacer with the AP formula.
Thanks Leo - beautiful image you linked to. I had to search for your reflection though! I will try the baffle flock modification to see if that cuts down the problem and also pursue the method you suggest.
Quote:
Originally Posted by atalas
Gongrats on the new scope Dug and look forward to seeing more.
Thanks Louie
Quote:
Originally Posted by bmitchell82
there are always nasty treasures doug
Aren't there just!!!!
Quote:
Originally Posted by strongmanmike
Great start Doug
That M42 looks quite striking, even with the reflection.
I think the reducer is the root cause of the problem here. Reasoning; consider that the new baffle design prevents this ring reflection for the standard field. Your field is pretty extensive based on your tarantula shot. The field for M42 is quite large too. You can also see another reflection just near running man. How old is the scope? If it is the newer version, try it without the reducer first as you plan. If the reflection still appear send it back. The new versions don't have this problem with ring reflections. If you find the reflection disappears then consider the following:
1) don't use the reducer.
2) consider buying another reducer or perhaps a flattner.
3) do the flocking mod.
I would use that order of thinking too. Do the mod as a last resort.
If you do the mod be careful of alignment of the optical system. Also look out for loosening the primary when you unscrew the baffle. I did not have this problem but another chap did and the scope had to go back to GSO for alignment.
With collimation remember to collimate with the focus on the outer side of defocus. If you wind inwards you will get incorrect collimation.
Generally this is a good start and you will get the reflection nutted. Are you using the standard focusor or another unit? If you are using the standard focusor consider this also as the source of the reflection too.
Please let us know how you go with sorting the problem and feel free to ring me should you have any issues. My number is in the bulletin.
I imaged M42 last night without the reducer - no reflections whatsoever.
Image was way softer than the reducer image for some reason and stars at edge were rounder than the non reducer image.
Couple of questions with the above in mind...
1. It would seem that the baffle is adequately 'flocked' - would preforming the flocking mod further reduce the possibility of reflections with the reducer? Or is that just a waste of time?
2. Leonardo's suggestion of adding additional spacers to slightly increase the f ratio might be a reasonable way to go?
Stock focuser replaced with 2" Feather Touch with 1.5" travel
I think both those questions are inter-related. The extension could minimise the present of the reflections. If there is a spacer added in between the reducer and the camera, it might well just get rid of the reflection. The reflection is right near the corner of the field, so that might be possible.
I don't think that flocking will make any difference in this instance. Mainly because I think these are coming from right outside the field of view and being allowed to be seen due to the presence of the reducer.
If possible construct a ray trace diagram to determine where the light source is coming from. It might be possible that there is a reflection just near the tip of the baffle that normally is not seen but when the reducer is present you see it.
There are some opticians here that might have a definitive answer in that regard. If you come to the meeting tonight we could have a chat about it then if you like.
Doug how are you using the reducer , its designed to be used like a nose piece and as such probably better kept closer to camera but you can also screw it onto a 2" nose piece to put it along way into the focuser and see if its better or worse. Mine screws straight onto the front of my oag and acts as the nose piece in this case.
May have to experiment before committing to a mod.
