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JGM1971

The "No EQ" DSO Challenge!

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QM's blog goes back a while there's a link to the blog on the earlier post with the tweaks I think.

Edited by happy-kat

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I love my refractor. The 80mm aperture gives a great field of view and it's so quick to set up and attach and focus the camera. It really is grab and go (if only the mount was as easy to lift).

Not that it helps your decision!

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It's interesting that my 76mm tele lens doesn't seem to suffer bad CA (there is a little bit). It has a rather different lens setup to a scope, with a set of supplementary lenses inside (I suspect these are a mild barlow that extends the FL of the objective from 300mm to 400).

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Hands up anyone who is using an Astro trac or barn door system!!!!!!!.

They qualify as an EQ system.

Anyone!!!!! 

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4 hours ago, Nigel G said:

Guys, I have been thinking a bit, Do I get a refractor?  I think a refractor would improve my imaging as my 150p scope is not really ideal for photography. My 200p would be fine on a eq5 , that's in a year or 2. Or do I get a better reflector designed for imaging. Any suggestions?  Reflector or refractor and which one below £200 I know it's not the right thread to post this question but it's for an alt az mount and I thought this the best place to ask.

Nige.

Ooh, now where do you begin! There are so many factors at play here Nige, but I would think for me the foremost consideration was focal length. If you are going to use an Alt-Az then it needs to be fairly short in order to keep star trailing in check. Mine has a native 700m and it works, and it has a FoV of ~ 1.85° x 1.25° with an AP-S sensor, which will be a bit tight for say M31 and the Pleiades, but it was OK with M42. These sorts of focal lengths are easily had in refractors. To me, the next thought would be aperture, 'cos you want to get as many photons down that tube in the time available. Large aperture refractors cost the earth. Large aperture reflectors tend to be long focal length, unless you go for specialised astrographs, which cost half an earth. How I envy those large photon hoovers, but then I think, OK, what do I put it on, it's got to be an AZ-EQ6 (expensive) if I want to continue with Alt-Az imaging, but then, really shouldn't I be using it in EQ mode? And then I've got to carry it all from upstairs and set it up in the garden each time. With no sight of Polaris. And with a reflector, I'm going to have to collimate it aren't I? I'm afraid I'm of an age where I want to be using the gear and not waste time fettling before I use it. Now, if I had an observatory the whole argument might be different, but there's no way that's going to happen!

As an aside, when I bought my refractor, convenience of use was uppermost, and that, together with cost, dictated the OG size. I wanted a reasonable focal length because my expectation was that I'd be mostly visual, with perhaps an occasional foray into astrophotgraphy. How wrong that was :icon_biggrin:. Still, 700mm I found is not too long, and with a reducer could be made better for larger objects. Yes, I'd  love a huge aperture, but with it comes a lot of other baggage which I'm not really prepared to accept, and at the end of the day I've no expectation of gallery class pictures, but I do enjoy the challenge getting the best out of the system and pictures of things I'd never get to see visually.

My two-pence worth anyway. Have fun going through all the options, dreaming, and window shopping.

ian

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6 minutes ago, The Admiral said:

My two-pence worth anyway. Have fun going through all the options, dreaming, and window shopping.

ian

And how absorbing window shopping can be-there's reading all the reviews, the comparing and finding out from others the up's and downs, and getting the best price before coming to your decision. Enjoy every moment of it Nige.

Cheers,
Steve

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26 minutes ago, LukeSkywatcher said:

Hands up anyone who is using an Astro trac or barn door system!!!!!!!.

They qualify as an EQ system.

Anyone!!!!! 

Not me, not me. I leaves all moi tractors in the barn.:laugh2:

Cheers,
Steve

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34 minutes ago, LukeSkywatcher said:

Hands up anyone who is using an Astro trac or barn door system!!!!!!!.

They qualify as an EQ system.

Anyone!!!!! 

I  have a barn door but I only post image from my altaz virtuoso on this thread, any other eq created image would be miss leading.

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I really just had to ask because im just blown away with the quality of images on this thread. I was sure some of you were cheating (did i just say that out loud).

 

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It is a fair comment to remind just how great the images are using the AltAz mounts and they aren't all the same mounts either though fashion a guess might all be made by Synita under the hood.

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28 minutes ago, LukeSkywatcher said:

I really just had to ask because im just blown away with the quality of images on this thread. I was sure some of you were cheating (did i just say that out loud).

 

Not me gov', honest! Nexstar 6/8SE is the only mount I've got.

Ian

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2 minutes ago, The Admiral said:

Not me gov', honest! Nexstar 6/8SE is the only mount I've got.

Ian

I dont wanna be seen to be using favouritism, but i'm really quite most impressed with your images. 

I also have an 8se and would love to learn your tricks of the trade.

Your images are inspiring.

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That's very flattering of you to say so, but we're all doing the same thing with the same sort of equipment, have the same challenges, and produce great output. All very much ongoing proving of concept.

Ian

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Luke (Paui) you have the 70mm refractor, could stick just that on your SE mount (to get going with to start with) and put your 450d onto the refractor. Steve's images show you can reasonably process out any CA issue to be less noticeable StarTools has built in functions to help there. That would be were I'd start get a feel for it.

Edited by happy-kat
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Ive always just been a visual observer but this thread has inspired me to very casually dip my toes into the "dark side" with the gear i have. As a non-astro imager i have to say that this thread is the best ive seen to get people to give it a go.

 

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14 minutes ago, happy-kat said:

Luke (Paui) you have the 70mm refractor, could stick just that on your SE mount (to get going with to start with) and put your 450d onto the refractor. Steve's images show you can reasonably process out any CA issue to be less noticeable StarTools has built in functions to help there. That would be were I'd start get a feel for it.

As a non-imaging type of guy..........ive never thought about sticking my 70mm on my SE mount and slapping my 450D on it. Thats an idea i'll work on.

Thanks for that.

 

Edited by LukeSkywatcher

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8 hours ago, LukeSkywatcher said:

As a non-imaging type of guy..........ive never thought about sticking my 70mm on my SE mount and slapping my 450D on it. Thats an idea i'll work on.

Thanks for that.

 

I agree whole heartedly with happy-kat, you've got little to lose by giving it a go Paul. One thing this thread has shown is that you're by no means doomed to failure if you do :icon_biggrin:.

What about the 130P? I've no experience with reflectors, but Nige might be able to offer an opinion. Refractors are more amenable to slapping a camera on though.

Ian

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28 minutes ago, The Admiral said:

I agree whole heartedly with happy-kat, you've got little to lose by giving it a go Paul. One thing this thread has shown is that you're by no means doomed to failure if you do :icon_biggrin:.

What about the 130P? I've no experience with reflectors, but Nige might be able to offer an opinion. Refractors are more amenable to slapping a camera on though.

Ian

Is that the 130p flex tube, they look like a good possibility, only a single secondary mirror support,  not sure about camera mounting. With a flex you have the option to have the primary mirror closer to the secondary to allow better prime focus?

The main issue with my star discovery 150p is the fairly thick secondary mirror support,  there's 4 of them and they are about 3 mm thick also the draw tube at prime focus is a good inch and a half into the main tube. This causes so much interference with the images. I think it's my biggest problem, it is a visual scope though,  even so as I said before the images I have are way beyond anything I expected 

I was looking at the 130 or 150pds designed for imaging, much better duel speed focuser and thin mirror supports. The primary has been moved closer to the secondary to achieve better prime focus..

I have been enjoying the research, as I  am in no particular rush will continue gathering info from here and around the interweb ☺

As Paul has the 130p it's got to be worth a go as long as the camera can be connected. Why not ☺But remember don't under estimate the power of the dark side?

Nige. Waiting for a clear night .

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As I  have run out of images to share, I was just browsing back in my photos from my beginning in December and January, I took a single image of an open cluster, I can't remember ex time but would guess a 30 - 40s, while trying to enhance the image I kept getting what I  now know as vignetting but didn't at the time, anyway I kept trying and this image kept coming up with quite a deep redish tone,, reading up a bit about the cluster I found it had a different description,  the Rosette neb.

Did I  capture this nebulosity or a bad case of vignetting ?   Here it is with star trails and all ☺ I had forgotten about it. 

PSX_20160507_004206.jpg

Nige.

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47 minutes ago, Nigel G said:

As I  have run out of images to share, I was just browsing back in my photos from my beginning in December and January, I took a single image of an open cluster, I can't remember ex time but would guess a 30 - 40s, while trying to enhance the image I kept getting what I  now know as vignetting but didn't at the time, anyway I kept trying and this image kept coming up with quite a deep redish tone,, reading up a bit about the cluster I found it had a different description,  the Rosette neb.

Did I  capture this nebulosity or a bad case of vignetting ?   Here it is with star trails and all ☺ I had forgotten about it. 

I can definitely see structure in the nebulosity but I can't see how much effect vingnetting is having and if there is also a background gradient. Again I'm jealous. I took 45 frames and got some beautiful stars but not a hint of nebulosity. Given its now raining maybe it's time to revisit the vault.

Edited by Filroden
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There is some in there amongst the red and colour mottle.

I took the liberty of a quick ABE in PI just to see.

test1.jpg

 

 

 

Edited by wxsatuser
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Nige, that's what I find to be the problem with this short exposure stuff, is deciding whether you've got nebulosity or just noise :icon_biggrin:. You can definitely see structure in there though, amazing for just a single frame. And Mike's confirmed it. What happens if you up the contrast, does it bring out more detail, or is there just too much noise?

Ian

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14 hours ago, SilverAstro said:

Yes I thought so too,  , , @LeeRich

Hi Peeps, sorry for late input.

I have attached a pic pf the focuser although the ruler is massively out of perspective so ignore it. I have measured it accurately and the measurements are correct.

The draw tube has an upper ring that unscrews, this collar is 13mm thick and with the aid of a T-mount to the inner thread i believe prime focus could be achieved.

I couldnt get prime focus when using my dads SLR hence adapting my webcam. But it was almost there so maybe the removal of this upper collar could work ?

I can get the thread measured of the inner 62mm length draw tube part if it helps.

Hope this helps guys.

Lee.

DSC_0080.JPG

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1 hour ago, Filroden said:

I can definitely see structure in the nebulosity but I can't see how much effect vingnetting is having and if there is also a background gradient. Again I'm jealous. I took 45 frames and got some beautiful stars but not a hint of nebulosity. Given its now raining maybe it's time to revisit the vault.

You surprise me Ken, 'cos you got a super image of the North America nebula with the same sort of exposure.

I have no experience using PS, but can I suggest that you have a play with StarTools. May be it's a case of the devil you know, but ST does seem tobe able to reveal faint stuff.

Ian

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