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Aramcheck

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Posts posted by Aramcheck

    HELP - cannot get image in focus using my Canon

    in Getting Started With Imaging

    Posted

    The EQ-2 mount also isn't good enough for general Astrophotography use, though you may be ok for Lunar images. To photograph deep sky objects you need a good solid mount which can be polar aligned accurately & which had very good tracking, so you can take long exposures without star trailing.

    When we started out with an EQ-2 130M, I made a wooden adapter so I could replace the scope with a camera and a findershoe attached to a piece of wood. You might find something similar would be ok for widefield shots, using your DLSR, though exposure times will still be limited.

    Cheers,
    Ivor

    DSC07564.JPG

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    • Like 1

    Drifting and zig zagging Images

    in Getting Started With Imaging

    Posted

    54 minutes ago, Felipe said:

    Do you know if that iPolar would work to check cone error as well?.

    No. It only helps with the Polar Alignment as it sits in the exit aperture of the mount's polarscope, i.e. you're aligning the mount to celestial north, whereas Cone error is caused by misalignment of the telescope axis relative to the mount.

    Best check that it would work in Southern hemisphere too!

    Cheers
    Ivor

    Barlow for SW200dps + DLSR ??

    in Getting Started With Imaging

    Posted

    I've been wondering whether a barlow could be used with my SW200pds & DLSR, primarily for planetary & lunar imaging, but also for some of the smaller DSO's (with shorter exposure times to try to compensate for guide error). Does anybody have any experience using a one with this OTA?

    Currently with my DLSR the focus tube has to intrudes slightly into the OTA in order to get focus. I presume I would have to wind the focus tube out with a barlow?

    If it is possible to go down this route, any recommendations on a 2" barlow?

    Many thanks!

    Ivor

    When are zoom eyepieces a good option?

    in Getting Started Equipment Help and Advice

    Posted

    I'm mostly attempting imaging these days, but in the past we've found that the zoom eyepiece (a Baader Hyperion) useful as it saves having to keep swapping over eyepieces and filters. The main disadvantage, being rather short sighted, is that I have to keep removing my glasses to get the full FOV & my wife and I have to then refocus whenever we take turns at the eyepiece...

    Cheers
    Ivor

    Feedback Please

    in Getting Started With Imaging

    Posted

    I've also initially had trouble centering / locating objects. I found Astro Photography Tool (APT) to be a great help, as I'm no longer reliant on the camera live view. APT also has the advantage of being able to plate solve images & iteratively refine the mount position until the object is centered (or positioned wherever you want  it to be)...

    For focusing, a Bahtinov mask (either made or bought) will help get precise focus, & here APT's Bahtinov Aid tool is useful too.

    If you find that you still can't get good polar alignment (or that it eats into imaging time too much), then have a look at something like the iPolar...

    Cheers
    Ivor

    PS: You're stars look nice & round which is a good start!

    • Like 1

    Star alignment when using software like stellarium, kstars, cartes du ciel

    in Getting Started Equipment Help and Advice

    Posted

    I believe in Stellarium you can use "Ctrl + 3" to sync the software, once you have found the target star in your finderscope & eyepiece.

    i.e. after polar alignment, you'd use Stellarium to go to a bright star, then use the EQMOD controls to reposition the target star in the fincerscope & then eyepiece, and then issue the "Ctrl + 3" command in Stellarium to sync position with the mount.

    I mostly use APT & platesolving as our scope has so far mainly been used for taking pictures... but in that too, after polar alignment I go to a bright star to set focus & sync the mount.

    Cheers
    Ivor

    M92

    in Getting Started With Imaging

    Posted

    1 hour ago, Paul M said:

    where does the overlay come from?

    It's the product of three scripts in Pixinsight. First you run ImageSolver (Script->Image Analysis menu) to plate solve the image. Then run CopyCoordinates (Script->Utilities)... followed by AnnotateImage (Script->Render).

    The AnnotateImage script has an option for the PGC (Principal Galaxies Catalogue) and you can export a list to a text file. I usually then import the text file to Excel & look up the redshift radial velocities on Simbad.
    (From the radial velocity in km/s, divide by the Hubble Constant (68) to get the approx distance in MPc & then multiply by 3.26x10^6 to get approx distance in light years)

    I'm not sure if other Plate Solving software also has the PGC catalog (eg ASTAP, PlateSolve2 or All Sky Plate Solver).

    Cheers
    Ivor

    • Like 1

    APT and Stellarium synchronisation

    in Getting Started With Imaging

    Posted

    16 hours ago, Padraic M said:

    I want to select an object in Stellarium and slew rather than using APT and its object catalog, is that I wanted to find Saturn and Jupiter which aren't in APT

    I had the same problem earlier this morning... but took the old school approach & copied the current RA/DEC position of Jupiter from Stellarium & then created a custom object in APT...

    I'll have to try the "Ctrl + 3" suggestion by @geordie85 as that will make life a lot easier!

    Cheers
    Ivor

     

    • Like 1

    How to capture comet Neowise - long or short exposure?

    in Getting Started With Imaging

    Posted

    I think it'll be too much magnification. The folks who've imaged it in our local soc have either used DLSR's with lenses & either single frames or on a tracking mount - or smart phones attached to binoculars..

    It is quite bright (naked eye visible) and large, pretty much fills the view in 8x42 bins / 102mm refractor.

    I haven't managed to take any proper pics of it, other than with a Compact digital (non DLSR) on a fixed tripod. This is a 5 sec exposure from back garden early Sat. morning along with some Noctilucent clouds.

    Cheers
    Ivor

    a few mins ago.jpg

    M92

    in Getting Started With Imaging

    Posted

    From early this morning... M92 in Hercules, taken whilst we were gawping at "C/2020 F3 Neowise" though bins. Lots of faint fuzzies in this one, although most don't have any Redshift (radial velocity) recorded on Simbad.
    Of those which are visible PGC2204313 is over 522 million light years away. (A Seyfert, PGC3096541 is given as 2.2 billion ly, but is too small to make out). Only got 24 usable subs out of 40 images due to guiding problems (& wind). SW 200dps + EQ6 + Canon 600d & 3min subs.

    At the end of the session I tried a 10min experiment to capture Jupiter using the DLSR live view & APT on 5x Zoom. Not wholly successful, but I'm not used to PIPP & Registax, so may not be processing correctly. In APT I unchecked "Live View Automation" (Tools->APT Settings) & set the APT camera settings to ISO 100 & 1/60 sec exposures. From the Planetary option in Tools menu I then used the option to save JPGs from the liveview stream. Gonna have to play around with things methinks...

    Cheers
    Ivor

    M92_v1.jpg

    M92_Annotated_Lo-Res.jpg

    Jupiter_rough.jpg

    • Like 9

    All-night stadium lights hit the news...

    in The Astro Lounge

    Posted

    So far £715 has been pledged against the £5k target required to force a judicial review, with just over 3 weeks to go.
    If successful it would pave the way to force councils to include appropriate measures against light pollution in planning applications, so I think it's worth supporting even though this action relates to Brighton.

    https://www.crowdjustice.com/case/put-that-light-out/

    BTW - There is a study ongoing at the moment (https://www.sheffield.ac.uk/architecture/news/investigating-road-lighting-and-effects-safety) which hopefully will provide scientific evidence on road lighting requirements. The current BS standards are based on very limited (& flawed) empirical data, and if I remember correctly only suggest minimum lighting levels. On major roads, the standards are based on traffic flow rate, with brighter lighting specified at junctions & other collision zones. In Residential areas the specification as it stands is fixed, so there's nothing on making levels variable based on time of night.

    With insect numbers dropping 2.5% a year (a fall of about 70% over the last 30 years - partly due to light pollution), there is an urgent need for action. It's also possibly the only environmental problem that can be solved literally by the flick of a switch...

    Cheers
    Ivor

    • Like 2

    Pixinsight Alignment when adding new data

    in Imaging - Image Processing, Help and Techniques

    Posted

    Pixinsight's "StarAlignment" process will cope with images from different days & orientations (eg flipped 180 deg), or if some subs are binned and others aren't. It is however best to only run StarAlignment once & then to integrate the subs.

    If need be you can manually align individual images using the DynamicAlignment tool, or run StarAlignment on your new subs using the same Reference image as you used originally.

    Cheers
    Ivor

     

    How to take a really sharp and nice picture of Andromeda with these specifications

    in Getting Started With Imaging

    Posted

    With the Canon 5D MkIII it looks like you could get away with ISO1600 (or possibly 3200), judging by the dynamic range curve: http://dslr-astrophotography.com/iso-values-canon-cameras/

    You could also try controlling the camera with Astro Photography Tool (APT) in case you're not getting good focus. (If you can, use a Bahtinov mask)

    As @PeterCPC says, the mount is not well suited for DSO imaging, so you'll have to experiment to see how long you can make exposures with acceptable star trailing.  I don't think anything can be done about field rotation though.

    Apart from the additional read noise & processing time, you should be able to reduce the individual exposure time & compensate by taking more subs.

    Cheers
    Ivor

    First Astro Attempt - Dispair!

    in Getting Started With Imaging

    Posted

    You can also control the Canon EOS 600d with Astro Photography Tool, running on a laptop. You just need to set the camera to manual mode & connect with a USB lead.

    All the settings for ISO / exposure are then taken from APT & the image is displayed nice & big on the laptop screen, with the ability to zoom in (& platesolve if you wish). The software also has a neat Bahtinov mask Aid tool too.

    https://www.astrophotography.app/

    Cheers
    ivor

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