Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

newbee need some setup and setting advice

  • Please log in to reply
8 replies to this topic

#1 sparksinspace

sparksinspace

    Explorer 1

  • -----
  • topic starter
  • Posts: 90
  • Joined: 04 May 2018
  • Loc: Perth, Australia

Posted 23 September 2018 - 02:46 AM

ok,

 

So I have Equipment wise 

 

Telescope

10" f4.7 manual dob

Camera

canon 450D

Accessories 

Tring adaptor for the camera

 

Knowledge of Taking photos

Not much more point and shoot did a introductory course about 20years ago.

 

So armed with this equipnment and knowledge I would like to start to fiddle with taking photos through my telescope.

 

I have managed to set up the camera onto the telescope.

focus via the viewfinder  

and in full auto mode take a picture of the moon.

 

didn't turn out to well as to be expected.

 

I'm basically asking for an idiots guide to setting up the settings and functions of my camera so I can take some pictures of the moon and planets.

 

I don't have a clue about "stacking" photos and all the other post image process that can be done but if I can at least take some decent photos then I can ask more questions and annoy more people later to do that.

 

any advice and tips would be great

 

Cheers 

 

 

 

 

 

 

 

 



#2 sg6

sg6

    Soyuz

  • *****
  • Posts: 3617
  • Joined: 14 Feb 2010
  • Loc: Norfolk, UK.

Posted 23 September 2018 - 03:46 AM

For astrophotography you really need a tracking scope/mount and it all works better if the mount is equitorial. Your dobsonian is neither. And therein lies the problem.

 

Cannot really give any suggestions. Not sure you can in effect obtain a one shot image of something on a short exposure of say 15 seconds. Thinking here of say (and it is guesswork) M42 at ISO 1600 and 15 seconds with no tracking. Might get something, unsure what.

 

Moon will image but that is big and bright, say ISO 200, 1/100 sec.

 

For visual you have a nice scope, big aperture, alt/az mount and you nudge and follow objects.

AP requires something along the lines of a solid equitorial mount with goto and the scope is usually a small item - say 72mm ED/apo or 80mm ED/apo. Lots here use the 130PDS reflector.

 

The bits of equipment have the same names, scope, mount etc, but are at opposite ends in some ways.

 

DSLR HAS to be set to Manual, You define the ISO, You set the exposure time, You do the focusing - think there is one other - got it set the DSLR to what is termed B (Bulb for exposure length = ignore the 30 sec above).

 

AP is basically:

Goto EQ mount, small fast scope, DSLR, Intervalometer.

Polar align the mount, attach scope, perform the goto alignment, set DSLR ISO etc, attach DSLR, focus scope/DSLR, set Intervalometer to say 10 second delay, 40 second exposure, 20 second Wait, 30 exposures.

Hit the Go button, you have 10 seconds to put the intervalometer somewhere, then it takes a 40 second exposure, then waits 20 seconds before starting the next. The exposure/wait cycle is repeated 30 times. You go home and stack the exposures collected.

 

Problem is you cannot do this (well I couldn't) with a manual dobsonian.



#3 Hesiod

Hesiod

    Vanguard

  • -----
  • Posts: 2410
  • Joined: 13 Jan 2013

Posted 23 September 2018 - 05:27 AM

You could probably get better results on the Moon through "digiscoping" (id est, take pictures of the image in your eyepiece; it is easier with a long focal eyepiece).

If want to take prime focus pictures, I suggest to use the camera manually, focus in the liveview (at 10x) and try to keep exposure as low as possible, even if this would mean forcing the ISO: this is the only way to counteract the fact that Moon is moving across your sensor, leading to blurred images.

Shot .raw files, and dabble a little with post-processing softwares to improve sharpness, saturation, etc...and maybe resize at 50% to make the picture looks sharper (it will be pretty large anyway).

 

The other option is to film the Moon (or take a large number of pictures), and resort to softwares like AviStack to compose the final image, but without tracking it would be a pretty nasty task.

 

Planets are even harder due to their smaller size and lower brigtness, so I would suggest to make some practice on the Moon first; also, with such a low sampling, do not expect nice results.

If like to craft things, may build to yourself an equatorial tracking platform, which would make much easier to resort to "lucky imaging"  (shot a ton of pictures and stack them together to get the best from each); with the help of the platform, could think to use a Barlow lens to add more "zoom" (=better sampling)



#4 sparksinspace

sparksinspace

    Explorer 1

  • -----
  • topic starter
  • Posts: 90
  • Joined: 04 May 2018
  • Loc: Perth, Australia

Posted 23 September 2018 - 06:55 AM

I'm not looking for showroom quality just wanted to know if it was possible to take a photo of the moon at prime focus with my telescope. just went out and took some pictures.

 

Quite easy really and not bad pictures.

 

was more wondering what camera settings to use on the moon to actually do it. at 800 ISO and 1/1250 it was not bad. 

 

is there a setting to keep the mirror open so it doesn't shake while taking the picture?



#5 sparksinspace

sparksinspace

    Explorer 1

  • -----
  • topic starter
  • Posts: 90
  • Joined: 04 May 2018
  • Loc: Perth, Australia

Posted 23 September 2018 - 07:02 AM

looks like I probably put in the wrong forum. my bad dident read this was for DSO imaging.

could a mod please move into the solar system imagining or the DSLR imaging forum please.

 

I'm not looking to image DSO's as this would be very very difficult with my setup.

 

Cheers



#6 Hesiod

Hesiod

    Vanguard

  • -----
  • Posts: 2410
  • Joined: 13 Jan 2013

Posted 23 September 2018 - 07:06 AM

I would try shorter exposures, even 1/4000 (remember, the Moon slowly crawls across your sensor; longer the focal, id est higher the resolultion, more evident the blur); with a bit of "computer magic" could even manage to print an A4-sized shot of the Moon for your bedroom.



#7 APshooter

APshooter

    Gemini

  • *****
  • Posts: 3275
  • Joined: 14 Oct 2013
  • Loc: Camby, In.

Posted 23 September 2018 - 10:20 AM

For imaging the planets with a dobsonian, you just need a camera like the ZWO 224MC and several piece of freeware, Like AS3! and Registax.  Here's a very quick primer on the process:

 

http://www.amateuras...aphy/4593463933

 

https://www.planetar...w-yann-le-gall/

 

It is certainly possible to get great pictures of the moon with your setup using the above techniques. 


  • sparksinspace likes this

#8 RedLionNJ

RedLionNJ

    Mercury-Atlas

  • *****
  • Posts: 2964
  • Joined: 29 Dec 2009
  • Loc: Red Lion, NJ, USA

Posted 23 September 2018 - 10:36 AM

Hi SparksinSpace,

 

You are on the right track.  With the equipment you have, single exposures of the moon (even perhaps a small Jupiter with its brighter moons) are your best bet.

 

I reinforce this because:

 

a) you have a 47-inch focal length and an f/4.7 focal ratio

b) you are not going to get "close-ups" of anything without tracking ability

 

Experiment a bit with the moon. Get as sharp a focus as you can (does the 450D have liveview?)

Then once you have focus, work on exposure (the two may come hand-in-hand). Slight under-exposure is preferable to over-exposure. Max your ISO at 1600 - you can certainly go lower on something as bright as the moon.

Not sure if the 450D has mirror lock-up or not. I know my 550D does. Check in the "Fn" settings. If it does, the first shutter press will lock the mirror up and the 2nd shutter press will trigger the exposure. This is best done without actually touching the camera, of course.

 

Now, since the scope isn't tracking, you'll have to make good use of a well-aligned finder to offset the scope in such a manner as you will allow the moon to drift across the middle of the field (as best you can estimate), then take some exposures when you believe the moon will be right there (well-aligned finder useful again).  

 

Remember you're working at nearly four feet of focal length. Picture a regular telephoto camera lens with a focal length of nearly 1200mm !!!!  Things are going to move very quickly across the field - nearly four times as fast as they would with a 300mm lens. This is sometimes hard to envision unless you've experienced it.

 

Taking GOOD photos through a non-tracking decent-sized scope is not easy, but it's not impossible for bright objects.  Hang in there!


  • sparksinspace likes this

#9 TelescopeGreg

TelescopeGreg

    Vostok 1

  • -----
  • Posts: 160
  • Joined: 16 Jul 2018
  • Loc: Auburn, California, USA

Posted 23 September 2018 - 01:30 PM

You're basically doing planetary photography, vs deep space, so the basic technique will be to take a high-speed movie of the target, and then use software to sift through the bazillion images to pick out ones where there is an ever-so-brief moment of stillness in the atmosphere.  It will then paste those together, giving you a clear image of the target.  As noted, the Moon and Jupiter are probably your best subjects for this, given the equipment you have.  Saturn might work out, too, depending on how much magnification you can bring to it, and how still the air is where you are.

 

Don't totally dismiss grabbing a "snapshot" of some of the brighter deep space objects, such as the Orion Nebula or one of the larger globular clusters (whatever works for your hemisphere).  Max out the camera's ASA and see what you get.  It's not going to be something you'd put in a coffee table book, but perhaps good enough to remember the event by, as one would do with a somewhat marginal snapshot during a vacation or sporting event.  You've got a bright and fast enough telescope that a 10 second exposure might just work.  Yeah, the stars will be a bit streaky, but that's not the point.  You just captured something awesome that one simply can't see without the telescope.  But a warning; doing so may lead you into the dark side of DSO...  It did for me.


Edited by TelescopeGreg, 23 September 2018 - 01:30 PM.



CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics