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I had a go at a little imaging at the weekend at our small gathering in Lincolnshire.

I used my 24-70mm sigma at f4 on a dovetail straight onto the EQ. My intention was to take 10 3 min unguided exposures but unfortunately I only ended up with two for this image.

I was hooked up to my laptop and on my first run I took five but ended up with 3 failed. I then took 5 darks, again with 3 failed, at this point I must have knocked my focus as the following 5 lights were out of focus and again I had three failed. I forgot to take the bias frames.. :rolleyes:

post-13491-0-71799900-1367939313_thumb.j

If anyone could shed some light on why I am only getting two from five I would appreciate your help.

I am keen to do some more wide field imaging with this little lens as it seems to give me nice results. I have seen Psychobilly post something that can be attached to the lens that I believe gives micro focus and focus lock but I can't seem to find it.

I also need to be able to achieve better framing and read that a ball head can be used between the camera and dovetail but wonder how this affects my tacking as I will be doing unguided.

I am though very pleased with my image and looking forwards to trying some more.

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The pics very good for a relatively small number of subs the brighter "constellation" stars are nearly always going to bloat compare to the background ones

What make and model camera and Lens are you using and do you have a laptop or netbook with you to control it?

If your using a Canon Canmera and AF compatible lens you can use either APT, Backyard EOS or The EOS_Utils to remote focus the lens from the "computer" with the first two you can even have the benefit of "FWHM" based autofocus, I tend to lock the focus ring with micropore surgical tape to stop it being moved accidentally or drifting... if the lenses are USM (Canon) or HSM (Sigma) they can still AF or remote manula focus with the manual focus ring locked...

Some Lenses will allow remote AF with the lens switched to MF Some require the lens to be left in AF...

http://stargazerslounge.com/topic/116670-canon-1000d-remote-manual-focus/

The TS Microfocuser is an attachment that clamps to the lens body and the focus ring and allows you to make tiny adjustments to the focus and also "lock it"...

http://www.teleskop-...-D---135mm.html

I made my own in the workshop ... but it's been handed on a couple of times since I now use a netbook to control the camera running APT.. I am also starting to look at controlling my canon camera form Android Smartphones and Tablets... I'm having mixed results at the moment but the software is still in Beta...

Peter...

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Very nice image, i'm looking forward to imaging the Cygnus area! I have been using the microfocuser that Peter has suggested in the post above, great little gadget!

Peter, what software are you using to control the camera? I'm interested in having a look. Does it allow you to focus from the tablet or smartphone?

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I'm using DSLRController (Beta) with a Samsung Galaxy Tab 8.9 running Android V3.2 .. I use a cheap OTG Adaptor cable to give me USB bConnectivity and so far have used it with my Canon 7D and Canon 1000D...

I still cant get it to work properly on my Samsung Galaxy S2 running Adroid V4.1 ...

A little bit more info here....

http://stargazerslou...ndroid-devices/

You get the same remote manual focus controls that you do in Remote Utils namely the <<< << < > >> >>> buttons for coarse and fine adjustments... You also get a whole host of real time exposure indicators as zebra stripes on the liveview video... The List of future functions looks very impressive and people payign for the beta are supposed to have a special raet on the full app when it's released...

Peter...

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Thanks Peter,

I have just had a look at the focus link and will have a play with that shortly. I must try that focus part out it looks very interesting.

The medical tape :rolleyes: yes, I remember you mentioned that one to me once before and I had forgotten that.

My camera is a 10000D and the lens is a Sigma 24-70mm EX aspherical. I took my focus by zooming in with live view to the farthest light I could see which was around 20 miles away. I then hooked up to my laptop and opened the EOS utilities. I just able to make out Deneb on the screen at 70mm but found this impossible later when I tried a couple of shots at 24mm, I expect this is just how it is as the image on the screen just is not bright enough.

The annoying part is that I lost 3 out of every 5 shots I took as the screen in EOS just said 3 failed. I do not understand why this is happening, could it be my average SD card or are 3 minute exposures too long for my poor Canon, or maybe I was boiling the sensor?

The other part I would really like to get a grip of is mounting. I did this shot by taking the dovetail off my billy optic ED and connecting it to the camera (a great fit). As I am mounting directly onto eq6 this then leaves me with no ability to frame my shot as I can not rotate the camera. I have seen a thread on the forum where you have two cameras mounted either side of your scope and have connected a ball head for adjustment. How does this work as I would have thought that if I move my camera this will have an effect on my unguided tracking icon_scratch.gif.

No my camera is 1000D not a 10000 D :)

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Once the mount is polar aligned you and tracking at the sidereal rate you can point the camera(s) at any point in the sky.... if your autoguiding then the imaging camera and guide cams shoukd be in the same general area..

Most of the time I dont bother with star alignment just setup the mount, roughly PA it with the polarscope then skip alignment and manually start the mount tracking...... The ball and socket heads allo for a lot of adjustment... you can also avoid the need for a meridian flip when imaging through the meridian...

The sigma might need to be left in AF mode to work with the remote focusing.. I have noticed that my EX 300/2.8 DG APO needs to be switched to AF where my canon L series lenses will remote focus in AF or MF mode...

Peter...

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It's a long time since I used EOS utils to capture a sequence what settings did you have... if the camera is busy when the "timer" wants to start the next exposure then IIRC you get a failed image - this can include downloading the image to the card and/or PC or taking an and processing an in camera dark ... I guess you had the in camera long exposure noise reduction turned off and that you were leaving sufficient gap between captures to allow the camera to finish what it was doing? I used to capture to card and allow 10-15 between shots

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I was set for 3 min exposures and shutter set to 4 mins.

I am not sure if I had noise reduction turned off and on just having had a look I don't think I know where that is.

My card is a hama high speed 2 gig card so I should think I need a bigger one of these.

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If you didn't have the noise reduction turned off the camera would only make one complete exposure every 6 mins , 3 mins of "light" followed by 3 mins of in camera dark plus a couple of seconds of processing before the finished image got written to the card... that would explain the failed exposures in the "plan"...

The Long exposure noise reduction is enabled or disabled in one of the Custom Functions.. I cant remeber the exact one but will dig out the info...

Peter...

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I bet this will be my problem. I shall have a look in custom functions when I get home and see if I can find it.

Thank you very much for all your help Peter.

I am looking forwards to having another go at some more wide fields from this site we have found it is very good.

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I will go through the CFn settings that I use on my 1000D when I get home and let you know what they are...

I used to do a few darks during twilight and a few at the end of the session and grab others if there was cloud during the run.... Badly temperature matched darks can be worse than using no darks at all but that depends on the camera...

I Stopped using Darks with my 1000D...

Peter...

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The only two relevant ones are C.Fn-3 and C.Fn-4 which I both set to 0 ... if your not using Eos Utils to control the sequence then you might want to have a look at mirror lockup - C.FN-8 Eos utils doesn't support mirror lockup when you using the timer function.

If your using a timer remote you can cheat by setting the drive mode to Self timer and adding the self timer time to the exposure... When the timer remote tells the shutter to open the mirror will lock up and the self timer start counting down when the countdown finishes the shutter will open.. the shutter will close when the timer remote times out...

I very rarely if ever use mirror lockup for astro especially widefield stuff...

Peter...

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A good ball & socket head is invaluable for widefield AP work. Don't skimp on the head - it has to be absolutely solid for AP work- cheap heads tend to drift especially when loaded with big lenses. I'm using old Manfrotto Super Ball 268 heads which weigh over 2Kg each! They can easily hold a DSLR and a big telephoto lens though. A ball & socket head allows you to point the camera anywhere once polar aligned. Manfroto 268 Super Ball attached to an Dscf1901.jpgEQ6 Cygnus 50mm lens with above rig DSCF3179_stack_003_SQUNIT_800.jpg

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Here's one of mine with the Canon 1000D (BCF Modified) and Canon 50mm F1.8 EF II at F4 It's 2/12 hours worth of 4 minute unguided subs on my EQ3-Pro

SGL_WF_1%20Cygnus%20Nebs%20HLVG.jpg

I have a range of Manfroto Ball and Socket heads

Manfrotto%20BnS%20Heads.jpg

The Smaller 484 head is fine for a DSLR and Shorter lighter lenses, The 488 will handle the bigger lenses especially if they are mounted using a tripod collar - I have used it with a Sigma300/2.8...

Peter...

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Cracking image, this is what I am looking to achieve.

Would it be possible to let me know what camera and lens you used to achieve this and a bit of an idea on exposures please. I assume your camera is modded.

I had a look at the EXIF data- my Cygnus image was a stack of three 180s subs ISO800. Nikon 50mm lens stopped down to F4. Camera was an un-modified Fuji S5 Pro DSLR.
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