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Pleiades first light with my new SV80ED


Leveye

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First light with my spanking new StellarVue SV80ED-1 Refractor. Quite stunned at this lil Doublet for so far for besides some purple fringing that needs removal in post and some diffraction spikes (?!) it is beating the pants off my AT65EDQ triplet when it comes to detail. Amazing.

8-300 second lights 5 darks 10 bias frames ISO 800 DSS PS and LR. Let me know what you think of the processing and of those strange spikes on the stars coming from a refractor? Any ideas how that's even possible? I have sent this to Stellarvue but nothing back yet. No Field Flattener or filters used just prime focus camera to scope with a T-Ring.

post-28595-0-75945600-1392038428_thumb.j

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Hi there,

Very nice first light, congrats!

The spikes you see are generally caused by the spacers between the two lenses elements, check if your lenses have this if so it's easy to "repair"...just make a small mask just big enough to cover the 3 spacers, you will lose 2 or 3 mm aperture but you will get better star shapes :)

Cheers,

Luís

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no not pinched optics at all, you get them when your focus is perfect or nearly perfect. there was a thread some were on this that olly commented on about the foucsing. i had the same when i had my ED80 no need to worry. you have a nice image there and a well balanced sky. good job

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no not pinched optics at all, you get them when your focus is perfect or nearly perfect. there was a thread some were on this that olly commented on about the foucsing. i had the same when i had my ED80 no need to worry. you have a nice image there and a well balanced sky. good job

I like this answer! I was almost ready to take it apart or send it back. Many thanks. -Lev-

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Hi there,

Very nice first light, congrats!

The spikes you see are generally caused by the spacers between the two lenses elements, check if your lenses have this if so it's easy to "repair"...just make a small mask just big enough to cover the 3 spacers, you will lose 2 or 3 mm aperture but you will get better star shapes :)

Cheers,

Luís

I have heard of this. It is mentioned in a book called DeepSky Imaging i believe. The washers/spacers are entering the imaging area of the tube. From looking at it i see nothing. It is constructed and assembled quite well baffled some and painted excellent inside the tube. Thank you i will experiment with this!

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Hi there,

Very nice first light, congrats!

The spikes you see are generally caused by the spacers between the two lenses elements, check if your lenses have this if so it's easy to "repair"...just make a small mask just big enough to cover the 3 spacers, you will lose 2 or 3 mm aperture but you will get better star shapes :)

Cheers,

Luís

More likely indeed. Pinched optics typically create more pronounced triangular centres

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I sent a cropped version to StellarVue and they are saying pinched optics caused by cold temps is the most likely reason but are not offering any solutions which i find interesting. This was taken in 55 degree weather so not very extreme. Looks like i may be on my own here and maybe doing a self repair on it. Or just live with it for it's not that distracting. Thank you all for the thoughts on it.  -Lev-

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Nice image and very interesting about the spikes as I too have these on this object with a TV85. The strange thing is I haven't had them on other  objects. I haven't taken may pics but I wonder if it's something to do with blue light? The only reason a suggest this is that my Horshead and Rosette which ar mainly towards the red are fine, just an idea.

post-195-0-53023500-1392235984_thumb.jpg

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I think the small aperture mask might sort it. However, these are mighty bright stars. They can throw up artefacts. When I had OSC and mono Atik 4000 CCDs for a spell I found that I got a sort of 'lighthouse beam' effect from the colour camera on bright stars but not from the mono, and the 11000s I use now tend to produce these as well. So there's a chance that it might be camera. I don't find them very upsetting in your image (or in mine, really.)

Olly

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The spikes are uaually found with very bright stars either using DSLR or CCD OSCs and are caused to a great extent by the micro lensing deployed with the Bayer matrix or in my opinion by the borders between the micro lenses, personally I find them quite attractive. :eek:

Regards,

A.G

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no not pinched optics at all, you get them when your focus is perfect or nearly perfect. there was a thread some were on this that olly commented on about the foucsing. i had the same when i had my ED80 no need to worry. you have a nice image there and a well balanced sky. good job

Can confirm this. With the 80ED I get small diffaction spikes from the cell clips when the focus is spot-on.

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