Here's another 6 pane mosaic taken with my homemade CaK filter, 70mm frac @ f11 and DMk31 camera. I had a tweak with the alignment of the second interference filter in the setup and this seems to yield slightly more detail than previous images. I like being able to image the sun at these wavelengths with larger aperture than the CaK PST! :)
Monday, 25 April 2011
I've been away on holiday for a short break over the Easter weekend, however the day before leaving I finally successfully completed the prototype design for a CaK filter. This filter uses 2 sets of interference filters, both centred on 394nm, however these are set slightly offset to each other in a tilt tuned arrangement to tighten the bandpass still further. An energy rejection filter is also incorporated in the optical train, prior to the tilt tuned CaK filters which enables the filter to be used with either my 70mm or 127mm refractor. I haven't got many images so far from this setup, although first impressions are very favourable. Detail levels are high, and seem to have better resolution than commercially available Lunt CaK wedges? Maybe this is a result of a tighter bandpass? The Coronado CaK setups have a 2.2A pass, where as the Lunts have a 2.4A pass.
Transmission levels are very high, and while most definitely not suitable from a safety point of view for visual observation, exposure times are in the region of 1/2000th second at zero gain @ f11 with the DMK31. This has the potential to capitalise on the moments of good seeing, and also the possibility of exploring prominences at CaK wavelengths.
This is going to prove to be a very interesting filter!!!
The weather has been behaving this month, and as such i've been lucky to be able to observe and image on a regular basis. Here's bank holiday mondays full disk taken with the DS40 and DMK31. This is a 'one shot'. Today had alot of interesting proms and filaments on display which were a visual treat in the eyepiece!
Monday, 18 April 2011
The best seeing conditions of the year so far allowed me this morning to do a high res mosaic of active regions 1191 & 1193. The shot was taken with my 127mm refractor, Lunt solar wedge, 706nm TiO filter and DMK31 camera. The mosaic was made using IMerge.
For best effect click on this link http://www.flickr.com/photos/56424473@N05/5631419994/sizes/o/in/photostream/ for the full size high res version of this image - MUCH better than the small preview on this blog!
Sunday, 17 April 2011
Solar activity is really hotting up now, with several large active regions on the disk. Here is a good example of this in the form of AR1191 and AR1193. This image was taken with the 127mm refractor at 1900mm focal length using the 706nm TiO filter and DMK31 camera. Unfortunately poor seeing on this day meant this was as 'close' as I could get to these spots before image resolution just fell away. Still, i'm pleased with the detail this image shows!
The 706nm TiO filter has been working overtime, with it's ability to produce top notch images in the worst of seeing conditions it promises to deliver the goods over and over again in this new solar maximum!
I got what I consider to be one of my best ever Ha full disks yesterday. This is a 4 pane mosaic stitched together in IMerge. Apart from a slight uneveness in brightness it's pretty much near perfect. The image was taken with my DS40 @ f16 with DMK31 camera. Click on the image to open up in full size!
I recently purchased a Baader K-Line CaK filter for ultra violet images of the sun. I'm in the process of making a hybrid filter using elements from a CaK PST to narrow the bandpass of the standard filter. I'm currently using ND3.8 film as the primary filter, though shortly are hoping to use this filter in conjunction with a bespoke Herschel wedge. Fingers crossed this is currently being assembled for me by an engineer in Italy. The plan will be to use this wedge to image solely at CaK wavelengths and should afford faster shutter speeds than i'm currently getting with this setup.
There is currently nowhere near the contrast achieved by the CaK PST, however by using the Baader K-Line and optical elements from the CaK PST should improve things considerably. I will then be able to use this setup with my 70mm and 127mm refractors and afford considerable improvement in resolution, without the 100mm CaK aperture limit imposed if I were to use a Lunt CaK wedge. As always, stay tuned for updates!
The problem with a blog like this is that there can only ever be one picture at the top of the page! Now I have images coming in quicker than I can blog them as the weather gets better! This is a 4 frame mosaic taken with the 70mm frac at f9 using the 706nm TiO filter. At the moment we have a spotty sun and this shows it well.
Thursday, 7 April 2011
I decided to have a go at putting a 'proper' mosaic together for the first time using IMerge - I've done this in CS4 before, but this is a time consuming process and the results in my mind never warranted effort in.
This was constructed using the 70mm refractor @ f9, 706nm Tio filter and DMK31. 6 panes were taken and joined in IMerge.
I'm really pleased with the results - lovely and sharp! The transparency was variable, and as a result the image is maybe not as sharp as I know it could be across the disk as a whole, but for a first attempt i'm impressed!
This is one to click and view at maximum resolution, plenty to see!
This image was taken with a low altitude sun ~ 10 degrees through so high cloud, and given these conditions i'm really pleased with the results. There's plenty of detail visible in the umbra and penumbra, and the granulation is reasonably prominent too. I'm fairly confident that with a higher altitude sun, good transparency and seeing that the results will be considerably better. Taken with 127mm f17 706nm DMK31.
I've been neglecting my Ha shots of late with my new whitelight filters. Managed to get this nice shot of a prom - looked great in the eyepeice!
I did take somemore avis however seems I knocked the scope out of focus, and so the rest were useless. Doh!
Sunday, 3 April 2011
Really happy with this image. If you look at the image of the sky below this post you will see what I was up against - very poor transparency with seeing conditions not much better! This was my first opportunity to try out the 706nm TiO filter with my 5" frac. Despite having to crank up the gain and exposure on the DMK31 to compensate for conditions I was really surprised with the results.
Looking closely at the image there is lots of detail visible in the umbra and penumbra of the spots, and the mottling of granulation. I'm really optimistic that with a properly clear sky i'll be able to get even better results still.
This image is testimony that this filter which works at longer wavelengths is better than the Baader Solar Continuum filter when seeing conditions are poor. On (rare) days when seeing is good the Baader Continuum as operates at a shorter wavelength should deliver a slightly higher resolution image. Until those rare days of good seeing actually materialise here in the West Midlands i'm going to stick with the 706nm TiO as far as i'm concerned this delivers the goods!
Thought I would post a picture of the setup i've been using of late for my solar work. On the EQ6 Pro mounted side saddle on Geoptik hardware is my 5" Meade refractor. This has been 'modded' with a Moonlite focuser, extra large dew shield and Harvington Strut. It is used with the Lunt Solar Wedge and variety of filters for whitelite imaging. Mounted next to it is my Ha setup. The is a 70mm f6 frac, and can be seen in the picture to have double stacked Coronado 40mm etalons mounted to it. The Coronado 'Solfinder' finder scope is mounted to it by means of a laser pen bracket. The smaller scope can also be used for whitelight when seeing conditions are poorer or if I want to get full disk whitelight images
In terms of developments of this setup, the plan is to fit an extra set of mounting rings to the Meade frac complete with a Losmandy mounting plate clamp, this will primarily be to mount the CaK PST on here also, however will also allow me to put my Meade ETX90 on there aswell.