Well, I've gone and done it now!
Just managed to pick up a Coronado SolarMax SM60 Ha telescope. Sexy gold tube like the PST and surprisingly only 400mm fl ( works at f6.6) came fitted with the dinky little solar finder!
The idea is fit my existing SM60 filter to the front and double stack ( giving about 0.4A) for solar surface detail; that was the theory!
Now find that the threads on the T-max adaptors are about 83mm and the objective is about 77mm...... Checking the Coronado site just tells me the filters have to be " matched" and that this can ONLY be done by sending the scope and the SM60 back to them to be "fitted"!!!!!
Rubbish! I've managed to convince the Local Agent that maybe I know what I'm doing and can "match" these filters myself!
Anyway, cut to the chase, I've found the Coronado "special adaptor ring"; the same one they use for the "factory matching" and hopefully it should arrive later this week.
On the assumption, that I DO know what I'm doing (!!??) I should be able to set it up for first light soon. Post some photos when I can.
Well, the Coronado adaptor arrived this morning. Strangely the 77mm thread fitted one of the SM60 filters very well, but not the other??
Managed, between showers and clouds to get the SolarMax60 + SM60 double stack set up and actually see the SUN.
First view showed multiple images, a quick adjustment of the front filter shifted them to the edge of the field ( 10.5 plossl) then adjusting the rear filter....... Whooooo..... the surface detail, active areas, granulation just jumps out, a little re-focus and I'm impressed!!!!!!
Also, maybe unexpectedly ( I was thinking about the reduced bandwidth) a couple of proms easily visible. Seeing was anything but steady, even these conditions show the capability of the double stack. A good satisfying first Ha light
I had on loan a similar setup recently, but only with the one filter. I especially liked the finder, same as what you have, simple but effective.
Now hook a camera up to it all.
Gary
I bought the DMK21 last year for Solar work. It gives great images at short exposure times and fast downloads. Had some success with the PST and the modded version, as well as the SM40 system, so I'm really looking forward to getting some creditable images with the new SM60 set-up. That's assuming we EVER see the Sun again over here... not looking good this week!!
Managed to get a few minutes of sunshine today...
Atleast it allowed me to set up and "play" with the filter tuning. You can definately see the difference at 0.4A when it comes to surface detail. The granulation literally jumps out and the small active areas are easily visible ( this was using a 7.4 plossl) the proms ( not many around) are not as easy as in the single stack, could be a mixture of the Doppler shift and broad variations in velocity.
I've also got a Lumicon Prom eyepiece with a bandwidth of 1.4 - 1.5A but it needs at least a f20 beam. Managed to pick up a 77mm Deep red ( 25A) filter from our mate Oldfield So in Hong Kong, so that combined with a UV-IR filter will be worth trialing on the 10" LX200 to see the differences with the SolarMax...
If I can get a bit more than a few minutes clear skies I'll try and get some images. It's at times like this I appreciate the Ozzie skies.......
That was quite brave of you to try the stacking of the SM60 yourself. I have never heard of anyone doing that - all posts on various forums speak of having to send the scope in, except for the PST. I'm glad you were able to accomplish it.
I have a PST, which I enjoy but I certainly wish the image was a better resolution, for the detail. I have imaged (DMK21 also) but I'm also still working out my EQ5 with goto.
The PST is a great staring point; as you say can be easily double stacked with a SM40 to give some very good images. They can also be safely "modded" to apertures up to 90mm.
I read all the other forums re double stacking SM60 filters and concluded, based on almost 50 years of building telescopes and lately spectroscopes, that if each SM60 gave a good FWHM of 0.7A in the Ha (or there about )that the probability of being able to match the "bell curves" ( whether symetrical or not) was just a matter of patience.
I've already had a look at the resonance bands ( in an SM40 etalon) using the spectroscope so I had a fair idea of what might happen. Part of the trick is to adjust the front element FIRST ( to get rid of the multiple reflections) this, by default, just moves the bandwidth off the centre of the Ha emission; the second filter is then "tuned" to give a fainter, but higher contrast image. You can see the effect very easily; when the bandwidths are almost sitting on top of each other the surface brighness is maximum and you know you have to move just that bit "off beam" to get the improved 0.4A bandwidth.
When I can get enough sunlight to test in, I'll take a series of spectroscope shots as I "tune" the etalons and see if I can measure the best ( and actual) double stack bandwidth.......
