Lightweight / Compact for Newt/Dob

[Charic]

Im aware of the restrictions of a camera mounted dobsonian setup. I only need to record , and  then  select still images from that recording via  the PC. My problem at present is my nikon DSL weighs  @ 0.7Kgs and I would prefer something lighter in the focuser. Are compacts with removeable lenses available. USB modified camera is a possibility, but will need the Mrs to loan me her laptop. Any thoughts please.

[Charic]

I `m liking the Nikon J1 however I`ll  initially use my DSLR with an elasticated support (around OTA & DSLR ) for security and stability, but will end up modifying a web cam, after seeing various other reports.

[Schorhr]

Hello Charic, what Do you want to record?

Planets and moon? You could try One of those 15£ compact camera/cellphone holders for eyepiece projection photography, or a compact system camera. The cheap ones have a smaller sensor then the DSLR though...

For deepsky objects you could get a PD from Astrophoto.co.uk, I was able to take images without tracking at a second or less from the ring nebula with 5", but a eq platform under the dobsonian telescope would help greatly.

Even with my 150£ laptop that's no issue ;-) You can get an old netbook like that very cheap used.

[Charic]

Schorhr..... I`ll record anything that i can see through the scope, only problem is, the scope is not driven, hence my reason to record, extracting images later.  Im not in any hurry to upgrade my telescope to a Catadioptric just yet, as theres nothing wrong with my Skyliner at present.  Just  needing some simple imagery for now. That PD is interesting,  Astrocam, and I could use for Home security Day/Night when not in use  on the telescope.

[Schorhr]

Why Catadioptric?

I just ment to use a lighter camera for imaging.

A mirror less system camera or any other light cam (but the later won't be able to take images through the focuser if you can't remove the lense, thus the suggestion imaging through an eyepiece or getting a mirrorless system cam).

The images will usually be worse then what the eye sees, at least without a tracking mount to allow longer exposures. Planets and moon are the only exception but even then stacking will increase the details greatly, but you allready know that I'm sure

Without tracking I used the Cam on 650mm focal length, though you could either use a reducer or due to the larger aperture Get away with shorter Sense up/stacking,

I used 1sec for these http://www.ringohr.de/tmp6/RingNebel_3.png and

http://www.ringohr.de/tmp6/alb_0.jpg

but as you can See the Ring nebula is very faint and the camera is neither perfect for Star shots nor Planetary.

IF a eq platform is an Option you could get away with exposures around 5 to 10 seconds in my experience with a canon 450d.

Finding stuff with the camera on 1200mm focal length will be tedious, at least without reducer, it's visible field is similar to a 6mm Plössl;

You could get a 70/700 or a 76/350 for under 20£ though and have them ride piggy back on your dobsonian with the camera, filming while you observe ;-) The sensitivity of the camera will still match the visual impression probably.

But without tracking / eq platform the results will be very limited, it was just an idea as I was so surprised that I got a shot of the ring nebula without tracking...

There are cheaper cameras at eBay but they won't have as much sense-up/integration and need more tinkering.

[Charic]

Schorhr......Just re-read my thread. Sorry about the jump to the CAT without any real description? I recently purchased a celestron 127EQ which can be motorised, but after messing with the EQ for a Month, I chose the Dobsonian (Skyliner) and I`m very happy with it. Now I just need to take the odd occasional image when using the Skyliner. My Nikon D5000 is probably more than capable, but I was looking for something lighter to fit into the focuser. Now if get into full astrophotography, I believe my next purchase would be a Catadioptric on a motorised EQ mount( which is what I should have said earlier?) Also out of the two lenses Im using, it seems the 8mm is the one I use most. I can locate well with the 9x50 finder then straight into the 8mm.

[Schorhr]

Oh, now I understand, thank you :-)

I don't know about that specific Cat, but the collimation/adjustment especially for photography is probably a bit tedious?

Is it an eq1 mount? It could be stable enough for AP with just the camera & lens;

I have an Astro3 mount but anything larger then a 102mm Mak seems too much for it photography wise :-(

Nice about video astronomy is that an AltAz tracking mount can be sufficient due to the short exposures. The noise is more of an issue then wit DSLR photography though.

I'm currently waiting for my mount, at 200€/169gbp they are affordable and may carry the 127ota well enough.

I don't know what the eq plattforms cost there or if you could build one; That's the only budget solution to make a 8" dobsonian track.

A small newton would work on a NEQ-3 that's not too expensive, much much more stable then the small eq, and quite portable. Everything else would be a compromise, but it all depends what image quality you are targeting at... Snapshots or pretty, sharp glossy color posters...

[Charic]

Schorhr........All I know is that my EQ is a GEM, have`nt found anything to say its a EQ1-3 for example. The telescope(Celestron127) is of the bird-jones type, so pretty much basic to be honest, there was a slight improvement with a decent lens viewing the Moon, but I wouldnt want to try much with it. I did have the D5000 attached during the Perseids (better images than the scope?) But the Nikons own tripod is steadier. Looks like i`ll put an advert for the celestron in the local papers for a cheapy Christmas present for someone, probably 40-50GBP. A certain high street store still selling them for 199.oo GBP? As for tracking the Dob, i could build a platform to incorporate declination, but I track satelites with this Dob! ( when they come into field of view) I just find it easy/natural to use the Dobsonian mount.  you see star trails at that speed? As for quality, A few images to go into 8"x10" frames to line the staircase  or a picture viewer. I have access to Hubble, for most images, as we all do, but a few images from the scope to show it works to visitors, would be nice.

[nightfisher]

you could always try A-focal imaging with a point an shoot camera and eyepiece adaptor bracket

[ollypenrice]

If your aim is deep sky imaging then a catadioptric would be a difficult way to start. It is best to start with a short focal length and fastish F ratio. Have a look at Steve's book Making Every Photon Count and don't believe a single word of what you read on manufacturers' blurbs regarding SCTs for DS imaging. Visit the DS imaging board to see what really works.

Olly

http://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/22435624_WLMPTM#!i=2277139556&k=FGgG233

[Charic]

ollypenrice......... cheers, that Book is on one of my lists. Since starting this thread, I`m discovering that Refractors are the better choice. but it will be a while yet, but at least I`ll be prepared.

[Charic]

Ollypenrice........ Still not ordered that book yet, but when I do, hopefully it will enlighten me, as its a highly rated book. Prior to that, my search has stopped at the Skywatcher Evostar 80 DS-PRO ED Apochromatic refractor. Its early Days yet. still happy with what I have.