I took down the RAG Solargraph that had been in place on the front wall of my house all last year and finally got around to scanning it in.

It was scanned at 1200 DPI, the highest resolution available on my printer/scanner, then rotated and flipped.  It took a while for me to realise that the flip was necessary in order to work out what I was looking at.  Seems obvious, in hindsight!  Then I created a negative image (thereby making the negtive positive) and cropped the edge beyond the south-west as it contained nothing but the shadow of the house next door.

Here is the result.  Apart from the above, the image is not doctored in any way.  Playing around with colours and sharpness didn’t seem to add anything useful, so I’ve stayed with the original settings.  You can just make out the image of my campervan, slightly west of south.  I’ve a better view to the east, but couldn’t quite catch the sunrise itself.  Silhouettes of trees and houses are vsisble along the skyline.  The white dots are street lights and ‘security’ lights that couldn’t be avoided (short of covering the camera up over night, every night).

It was an interesting experiment and the result is actually better than I expected, so I’m quite pleased with this.

Derry North

Photographs of solar surface 24-25/6/2020 at different settings on dial of Daystar Hydrogen Quark Filter

I took following photos through my Daystar Hydrogen Quark filter, with different settings on the dial on the filter. This dial varies from -5 to +5, and I wanted to see whether photos were better with one or other setting – those settings vary the tuning of the filter.

  • Sky Watcher Equinox 100m OTA
  • Daystar hydrogen alpha filter

After this analysis, I am still not sure which setting is best! However, visually, and also Damian’s previous assessment, was that setting -5 was most effective for my Quark H filter.

it is worth saying that these photos were taken before I sorted out the flat frames on FireCapture, and the alternate dark and light banding in the photos shows (Newton’s Rings).


+5 setting:

+3 setting:

-3 setting:

-5 setting:

First post (and first image)

Whilst I’ve browsed this site on and off over the years, I’ve never got around to posting anything on the blog. And now I want to, I find I’m not sure how to do it.

That is, I can add a new post, of course by selecting the New button, and I’ve even selected a category. But we are asked to add a second category, with the name of the poster, and to add a category if one doesn’t exist. I cannot see any way to do that. Will keep looking, but please say if you know how, or point me at some instructions if there are any.

Meanwhile, I uploaded an image for the first time yesterday and I’m wondering if anyone can see it. Andy had a look during the meeting and couldn’t find it. I can see it myself, but I wonder if anyone else can. Do I need to do something else to make it public?

Derry North


M16 this summer.

This is the image I shared in tonight’s meeting, M16 the Eagle Nebula and cluster in Ha, with the ‘Pillars of Creation’ in the middle. Nearly 3 hours (34 5-minute exposures).

M16 Ha
M16 Ha

I also grabbed a luminance layer for the globular cluster M14 to use with my RGB data, and this Luminance only image of M11 to add to my ‘Messier Collection’.

This is classifies as an open cluster despite being quite compact, to me it looks more like a small but raggedy globular!


M11 The Wild Duck Cluster
M11 The Wild Duck Cluster

Solar disc in Calcium H 25/6/2020

Hot on the heels of my Daystar Hydrogen Alpha Quark-filtered image in my previous post, I have now taken some images using my Daystar Calcium-H filter on the same scope and with same camera.

…Well I am on a roll – why not?

I have taken images using variety of settings – still need to decide which is best – so here are two images at opposite extremes of settings on the Calcium-H Quark.