Ok, my fellow stargazers, and especially the sun worshippers amongst you. I've just realized that I haven't made an astronomical purchase in quite a while. The nights are cold, but I still like looking at Sol during the day. So...
Have any of you done this double stacking that they talk about (screwing a Solarmax 40 filter into the front of a PST)? Was it worth it? How much does it cost? I already have a PST but where can I source the additional filter in Australia? Originally I heard that you got best results sending the PST back to Colorado and having them match the filters, but is this really necessary? Anything else I should know?
All information gratefully received and avidly read.
It cost me around 1200 for the DS filter, it might be better now that the dollar is nicer.
You don't need to filter match a PST. The solar max scopes you need to do this and if you have the solar max filters on their own. The PST you can just screw the DS on an start viewing straight away. Use the Tmax adjustment as much as possible, brings out differing detail ove the entire image.
The image is a little darker, but you get accustomed to this very quickly. If you are into imaging, you will notice that there is so much more detail.
$1,200 would be a bargain! Unfortunately, prices seem to have gone in the opposite direction to the $AUD and they're presently $1,899 on the Bintel website (Stock code: 7246, under Solar Observing).
Thanks for all your comments. $1200 I could almost come at, but $1900 and I'm coughing up my chardonnay. (I see BINTEL actually sell double stacked PSTs for $2200, which means they are throwing in the scope for $300! I'd be better off buying that and selling my own PST, or turning them into binoculars...) I'd better give them a call.
I think I've heard that Telescopes & Astronomy (http://www.telescopes-astronomy.com.au/), handle Coronado too, but I can't locate the brand on their almost unnavigable website.
There may be other vendors too, now that Meade own Coronado - perhaps any Meade dealer can stock them or at least get them in?
Tony is right, you only need the band pass filter to double stack the PST. I haven't seen them sold separately, the BP and BF filters are usually sold as a matching set either in BF5, BF10 or BF15.
I have attached a couple of pics of my set up on the Vixen Porta mount. If the seeing is really good I will unscrew the BP filter off the Solarmax40 and double stack it on the PST. The double stacked arrangement does result in a loss of image brightness which is not bad, the contrast is better for surface detail. Prominences lose out with this arrangement though and I have found the PST shows them much clearer. My Solarmax40 has the BF10 filter which is more suited to imaging. Having both scopes side by side is great for viewing with different magnifications. The T-Max filter on the Solarmax40 is better for viewing varying detail than the PST as it has a large range of adjustment.
Something else which is not mentioned is the fact that with double stacking, the T-Max tuner and PST tuner have be "tuned" together. This results in fiddling around with both of them until a sharp and clear image is formed. There appears to be some internal reflection with this arrangement resulting in a red shadow like image of the sun in the field of viewing. You can "tune" this out to a degree by having the shadow off to one side of the eyepiece field.
As a matter of interest, on the Solarmax40, the 40mm lens housing is integral with the BP and T-Max filter and has to be unscrewed each time you want to double stack. You have to be careful in doing this, particularly if you're in a hurry. I always take the two apart over a thick towel just in case and store the 40mm lens assembly in a safe place.
To answer the question, is double stacking worth it? I think it is a pretty expensive way to see just a little bit more surface contrast. The PST to me is really quite adequate and very satisfying particularly for the price. The Solarmax40 is really quite expensive compared to the PST and in actual fact does not perform as well in some respects, particularly viewing prominences.
