Solar imaging with a PST.

[The_PSY3NTIST]

Hi everyone.

I'm new to solar observing/imaging and was wondering if anyone could offer a few tips I have a PST and a celestron neximage and the best I can come up is the attached images. Where am I going wrong? I intend on getting the same sensor that is in the dmk21 b&w fitted into my neximage eventually but was hoping to get better images with this first. Can you get full disk with a 1/4" sensor and what it the best method for focusing. Could anyone recommend any good setting to set off with for surface detail and also prominences. Any help would be greatly appreciated

thank you

[Montana]

An excellent start unfortunately I have no experience with your camera but to get both surface and proms together you need to raise the gamma level, but not too great as you will get noise in stacking. It is a fine balance between exposure and gamma (don't touch the gain - the lowest is best). It certainly is possible and I personally prefer this type of imaging as I like a more natural looking Sun.

Alexandra

[The_PSY3NTIST]

Thank you for the reply. Good pointers to start from. I've had the sliders all over so that explains some of where I've been going wrong. As for the full disk, how do I get it all in? When I connect the CCD directly to the pst I only get about 2/3 of the sun. It's all probably simple and silly question but I'm not used to this imaging lark

[riklaunim]

You could try a mosaic from two images using Microsoft ICE. Without a bigger sensor that's the only option.

[DrRobin]

I don't think your Neximage will have enough FoV for a full disc in one go, so the way to go is a mosaic, you will get better detail and more uniform image in any case. Try a four panel mosaic for starters. Then try a Barlow and a 8 or 12 panel mosaic.

To stitch the images together try Microsoft ICE or Autostitch, both work quite well.

Like you I wanted a full disc in one go and whilst it is possible with my scope/camera the resolution from a 12 pane mosaic is so much better and the final picture in a different league.

Keep at it you will get there and your pics are a great start, it is just a steep learning curve.

Robin

[baggywrinkle]

I have found that the NextImage FOV is quite small and when looking at the Moon (a similar sized object) I only get partial views.

If I use it I use a field flattener to reduce the image size, not sure you can do that on a PST.

[Sp@ce_d]

I think that's a cracking first result. I've had a heck of a time trying to get the hang of exposure & focus with mine. Only focuses with a Barlow in place. Ive kinda lost heart with it for now but looks like you've got it.

Sent from my iPhone using Tapatalk

[The_PSY3NTIST]

Thanks everyone. Lots of useful tips there ill try it with the barlow and try doing a mosaic

How about a dslr? Does any one use a dslr with their pst? I've heard a x2.5 barlow will allow focus but not sure how much of the sun that would capture

Thanks again

[riklaunim]

You can use the Barlow lens screwed to the 1,25" camera nosepiece to get the focus at ~1.5x avoiding 2x or more. GSO/Revelation 2x Barlow has lens that is 1,25" threaded and I use it with PST and my camera.

DSLR could be used theoretically but as a color camera it won't be perfect. If it has the standard IR-cutting filter it may cut most of the H-alpha making it very dim too.

[pmlogg]

I never had any joy using my 450D through the PST. I did use a Meade LPI (couldn't achieve focus with my DSI Pro) but the standard advice is to use a fast frame rate mono camera like a DMK. The DMK41 allows full disc.

[Sp@ce_d]

I had another go with mine today in between the cloud & rain. I picked up a Tal 2x barlow the other week and have to say it is much easier to focus with that than the SW el cheapo one or even my TV powermate 2.5x! Much more stable focus with the Tal I found. Using the DMK in my sig.. requires mosaics with this one.

[JamesF]

The image of the sun produced by a PST is a smidge under 3.75mm across, so if you want to get a full disc image on the sensor then you need one that big. Add a 2x barlow and obviously the image becomes 7.5mm-ish. That's not really leaving a lot of margin for error or proms, either.

James

[mallorcasaint]

I would love to know what settings you use on your Neximage 5 for solar imaging. I can't seem to get a decent image at all using this camera on the Sun. The image on screen seems to have small crosshatching and I'm sure it is the settings.

[paulastro]

If I want to record anything with my PST I use a compact digital camera with a digiscoping adapter (designed for birding) which grips onto the eyepiece by rotating the adapter. It can give reasonable results on both prominences and surface detail. My compact has mostly auto settings, but with a camera with manual exposre for instance it would be easier to obtain more consistant results. The video facility on the camera can give reasonable results as well.

[Adrena1in]

I like the second image, and you're certainly getting better prominence results than I am.  I'm using a QHY5L-II with my PST.

Don't worry though, if you're disheartened to start with, perseverance will see your images improving.  I started with my Canon EOS 450D, and could only achieve focus by removing the little ERF filter, which I wasn't too happy about.  Could get the full disk in easily, but hardly any detail to speak of.  The QHY5L is fine if I only slide it a short way into the blocking filter/eyepiece holder, but can't quite fit the full disk in.  Almost, but not quite.  Using a cheap Barlow works okay, but I'm thinking a Tal might be next on the purchase list, if you say they're that much better.

My main problem at the moment is creating a mosaic.  Not tried Microsoft ICE though.  I've tried iMerge, Photoshop and Autostitch, and while the first two work to some effect, (Autostich, which I use a lot for landscapes, usually can't seem to match solar images together at all for me), I'm finding blending around the edges to be difficult.

[michael.h.f.wilkinson]

My DMK21 can only get partial disks with my LS35 (same focal length as PST), but you can create mosaic (at least of the surface). You need a 1/2" sensor like the DMK41 or ASI130MM to get the whole disk at 400mm. I much prefer mosaics to a large sensor. The former are easier of course, but the latter get far more detail. I often use my 2.5x powermate to get 1000mm focal length, requiring about 30 panes for a surface mosaic. I use AutoStitch64 rather than ICE however.

[Adrena1in]

I much prefer mosaics to a large sensor. The former are easier of course, but the latter get far more detail. I use AutoStitch64 rather than ICE however.

I see where you're coming from.  Yesterday, after work, I experimented a little and took some 320x200, 1000 frame AVIs with my QHY5L and 2x Barlow.  Wanted to focus on some interesting surface areas.  Only took a few seconds to create each AVI, which is benficial for me as I'm still using manual adjustments on my crumby EQ2.     While the little stacked images were nothing to write home about, it did occur to me that I could create dozens of them to gradually build up a full disk mosaic, which might not look too bad.

[andre2]

Hi, is it worth to buy a easy to use DSRL  €300 nikon camera as i am a beginner? Can i REALLY see the proms in full glory when i zoom in at camera mode? Can i also see them in the LCD screen of the camera good withoud to do ( mutch) tweaking? Thanks!!! ( for the pst or lunt 50)

[Pete Presland]

Some very nice detail there, I use a DMK21 for all my Solar imaging.

I never used a DSLR on my PST, but  I would be surprised if it could match a webcam for details. Happy to be proved obviously 

+1 for Autostitch, it stitches pretty everything I have thrown at it!