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daverave83

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Posts posted by daverave83

  1. Hi Dave.

    You've done well for such short narrowband subs.

    You're right, you need to go longer on your NB, the longer the better.

    What scope and mount are you using? Unguided?

    Is the camera modded?

    Flats would help this out as you'd lose the vignetting. which is masking the nebula quite a lot.

    It's just on a standard goto, Saving up hard for an HEQ5 Pro & APO Scope, eventually the SLT102 Will come my guide scope 

  2. Hey Guys,

    As the post says is there a way to control the camera and goto scope wirelessly? at the moment i setup my laptop outside and with my laptop and noticed that damage can occur if the temprature dropped below 0'c, at the moment i leave the laptop running over 2 hours whilst it takes pcitures so not the best route.

    What I am looking for is a simple setup and shoot, to all the normal procedures i.e. 2 star align and focus, then do the rest of the imaging in the comfort of my home, this will save in my laptop getting damaged.

    Security wise - a webcam should suffice?

  3. Hey there.

    I didn't say that a filter would turn an Achro into Tak, however it is proven that a Longpass 495nm does reduce CA upto 80-90%, these filters were specially made for Achro due to it's limits hence the reason why they also brought out the semi apo also, so people dont have to spend vasts amount of money on a tak and still get good performance.

    http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/6294607/Main/6294607

    check the 3rd image, for an achro that is impressive, so understand how you can disagree and that is your opinion however proof is in the pudding as they say and good quality images can be done but not as superior as a tak.

  4. Thanks Mac
     
    Baader Fringer Killer does indeed only remove 50% of the CA, and the price of them is about 50 quid.
     
    However reading various forums Baader Longpass 495nm filter can almost turn an Achromat into an AP, the only difference is the stars are either orange/yellow instead of the normal contrast.
     
    http://www.cloudynights.com/ubbthreads/showflat.php/Number/5047210
    http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/6113911/page/0/view/collapsed/sb/5/o/all/fpart/1
     
    My experiment is to see if at low cost you can get near enough the same images you get from an APO, eventually i will go for a Skywatcher Evostar Apochromatic ED80 Pro on a EQ5 Pro Mount, but that is a long term save.

    This the detail i have found 

    Application:
    Suppresses the secondary spectrum (blue) at achromatic refractors. Image definition is increased.

    35bi9mx.gif

  5. I own the SLT 102 GOTO

    And overall they are not bad scopes visually and some short AP if you learn about field rotation.

    They do stay with the object however they are not as superior as the GEM of EQ5 and above, i see this as a learning curve to understand of how to align and what is required.

    So what can you get imaging?

    a maximum of 70 sec exposures maybe more depending on when the goto re-aligns, the results i had that 2 images out of 5 has field rotation after 65 secs, which i think is great of you want to understand what AP is all about to give you an idea see below.

    153xp4n.jpg

    what are the dissavantages?

    Scope does get the full affects of CA (chromatic aberration) which causes halos around bright objects, however fringe killers filters > filter out the wavelengths to reduce the affect. Goto isn't as good as GEM / EQ5 however overall best for beginners

  6. Thats an amazing result for a single 90s Sub.

    I understand what your saying about make use of the night, but sometimes some objects need more than just one sub to bring out the nebulosity, but that's just my humble opinion.

    I wish i could just take one sub of an image and be happy with it, but sometimes some obstacles get in the way that hinder an image. for example cloud, wind, trailing, field rotation out of focus.

    An average night for me is 2hrs Minimum, but i let the Autotimer do the work, all i keep an eye on is the weather and that nobody wants to pinch my equipment.

  7. Agreed that you can't remove the wavelength completely as this due to the glass and the way it bends colours, but looking to ways to minimise it with a low cost.

    Looking at the prices of APO's and EQ5 you are looking at spending 1k+, however if you are thinking of dipping their feet into AP at a low cost i want to look at filters that can reduce the amount of CA to semi APO standard.

  8. That kind of makes sense.

    I currently have an HA Filter, so this means i would have to refocus on the blue spectrum? the question is how would i do this?

    So lets say i got M42 in my live view on my DSLR and got the focus to a pinpoint star, i would assume that it is looking at the Green/Yellow wavelengths how would i refocus on the Blue Wavelengths? could a OIII filter do this?

  9. Hey all,

    i am looking at different filters to see which results reduce CA, hopefully by the end of my investigation i can provide people who have Refractor Scopes better imaging views particulary on Deep Sky Objects.

    So what is Chromatic Abbreviation?

    This is where the spectrums of light don't focus at the same length, for example the focus is correct for Yellow and Green, but the out of focus is Blue/Red which is why you get Purple Halos.

    I have searched all over the internet for guides and way around to remove the CA, unfortunately there is no way to remove 100% of this,  unless you focus on each spectrum of colour which can be very time consuming and expensive.

    Whats Filters will be the investigation?

    Wratten 8 =

    Baader Longpass 495nm =

    Baader Finge Killer =

    SkyGlow & Moon Filter =

    Once the weather clears i will try out each filter and post the final result.

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