OK, so here's first (and maybe final) bunch of images from the Transit of Mercury. Two in Ha and one in white light.
Ha: Coronado 60mm filter on my Megrez 80, with QuickCam Pro 4000.
White: Baader solar film on my 12" LX200, with 350D.
I have plenty more photo's and video's I haven't processed, but I'm not sure I will. I have enough white light photo's to do a sequence from sunrise (WA) to completion of the transit, shots taken every 3min and then every 10 seconds at the end. But I'm not sure how best to process them in to one.
Leading up to the day I wasn't confident of a clear morning, with showers around and lots of cloud. Luckily though it was mostly clear for me, except about 7:30 when fog lifted out of the neighbouring valleys, obstructing the view for about 20 minutes.
The filter I was using cost the society about 4 times the price of a PST. At the time it was purchased PST's weren't available (it's several years old).
My comparisons between this filter and PST's show the PST's are significantly easier to use and as such you end up with better results. It can be tricky to align the filter with the scope, even a good rigid scope like the Megrez, and tricky to know you've got it at the best alignment. The PST is just all setup and working every time.
I know several people with PST's, one with an add-on 40mm filter on the PST. I think the 60mm filter I was using beats the normal standard PST for detail (when you get it aligned right) but the PST with 40mm filter is much better than the 60mm filter.
I only occasionally manage to get the 60mm filter working optimally, it usually requires a bit of time to tweak it to get it right. The PST's just work.
If I were buying a solar filter of some sort I'd definitely go with the didicated solar telescope (PST or whatever can be afforded).
I was looking at the solar shot using the Solarmax 90 over at spaceweather this morning, moaning over the shot and a 90, wishing and wishing, and my wife said "what's stopping you" Of course she's never seen the price
I'm not an expert on this solar stuff (usually prefer it and the moon would just get out the way), but...
I believe the extra filter is simply like the 60mm I used but a 40mm. The thing is I think it's higher quality (shorter wave length range??) so it enables you to see lots more detail in surface and prominances. That's about all I understand.
Of course a PST is never going to compare in viewing quality to a 90mm or solarmax or whatever they are, from what I have seen and tried it's simply not possible to get the sunning high detail photo's using a PST, all comes down to resolution, filtering range and cost I guess..
I'll need to look into this a bit more I guess. I've been thinking of getting the 60 to go on the Orion. What's this "alignment" your talking about? I gather the filter doesn't just "pop" onto the end of the lens cell.
The H-alpha filters have a 'tuner' on them, to fine tune their alignment with the optics of the telescope - this sort of system exists on all H-alpha scopes in some way that I'm aware of.
In the case of putting something like the 60mm on a non-dedicated scope, it's like you need a massive tuner, to not only fine tune the alignment but to get it in the right ball park to start off with. It's quite a small critical range where it works well.
To mount the 60mm on my scope (or anyone's scope - it's a club owned filter) the club had made up an adapter that has 3 screws which tension on to the outside of the OTA, then the filter threads on the front (I might take some pictures when I'm at home tonight). As much as you think you have the filter flat to the front of the scope (can push the adaptor hard up against the end of the OTA), it's never quite in the right alignment.
So you need to losen the 3 screws a little, fiddle around with the movement to get it roughly right, tighten the 3 screws, then play with the actual tuner on the filter to make fine adjustments.
There's the tuner on the filter and a tuner of sorts on the right-angle blockout filter bit .. I think the one on the blockout really only adjusts brightness and position of the ghost images - from what I see - but I'm not great on the specifics - I'm a deep sky guy!
So... the trick for this filter I have, whoever's scope it goes on we often have to spend a while fiddling around with the alignment of the filter to the scope before starting to fine tune it with the filter's built in tuner. For my scope it's relatively easy because the Megrez is built so solid and accurately. We have tried it on some others, like a older meade refractor (perhaps a 80 x 900 or so?) and it was a royal pain - just very hard to get it aligned because the OTA being a bit old or whatever, wasn't as rigid, perfectly secure and straight and all that, so it was just very hard to get working. I've seen that in some other cases too.
Something else affecting the ease of the activity is length of the OTA. With my short little Megrez I can easily reach the filter, so I can look through the eyepiece, un-do the 3 screws, move it around until it's about right, then lock it in place and then use the built in tuner. With the other OTA's I've used it on, the OTA is too long for one person to do that, so you need one person looking through the eyepiece and one moving the filter. Co-ordinating that can be tricky especially when you're not sure if it's a ghost image or the real image you are seeing.
That's just my experiences. I'm sure if you owned one, got used to it, used it on the one scope, it would not be such a problem as I have experienced. I only rarely use it - I've had it the last few months and have maybe used it once a month.
Thanks for the info Roger. It's given me some things to think about.
So if it were you thinking about getting a solar outfit, you would go for the dedicated 60mm scope over the filters, or the PST with a 40mm filter with associated less resolution?
I guess the other thing to is whether a full solar image is available without severe vignetting using a pst and a 300D ....or if that is even possible.
I'd have trouble going past the PST with additional 40mm filter. It's really really easy to setup and always "just works".
But... the PST's aren't great for photographic work (my webcam will only reach focus on a PST if I use a Televue 2.5 x barlow ... my celestron short 2x barlow won't do it, or any other combination I've tried.
Also the PST's have a much smaller "sweet spot" than the 60mm filter on my Megrez. If I get it right, I can see the full solar disk with wonderful detail the whole way around in my Megrez with 22mm Panoptic. That's nice. Moving it around makes little difference. However in the PST's you really need to move the image around as you see lots more detail when looking in the central sweet spot.
If I had the money I'd go for a 60mm dedicated solar telescope, one of those SolarMax ones or something. I can see why they would be of such a benefit considering the compromises between the PST vs 60mm filter on non-dedicated scope. But I can't see myself ever justifying spending the money on it at this stage, so the only viable option would be the PST and then upgrade by adding the 40mm filter on if/when I had the money.
You really notice it when you get the alignment perfect. You can think you have it right, but not really. Then you tweak it a little more and "wow!" there it is, stunning detail. There's a lot of times I use the 60mm on the Megrez and don't quite get it right, I can tell it's not the best it should be. The incidence of that is reduced with a PST where it's all aligned and you just tweak it.
... gez, I didn't know I knew so much about this thing... I must've learned a bit in the last few months I'd better stop talking and go meditate on a 12" mirror before I convert to the dark side (err... 'light side') of solar viewing!
I know what you mean by tweaking. Sometimes it part of the fun getting everything to just happen right. But there is alot to be said for just plonking it down and enjoying something
Thanks Roger.
Y'know the weekends coming, why not get that 60 and your Megrez out and see what you can do with it You never know you might just end up getting one of those lovely little DMK cameras to go with it
![[1ponders]'s Avatar](../vbiis/customavatars/avatar45_9.gif){kind=avatar}
Of course she's never seen the price 
You never know you might just end up getting one of those lovely little DMK cameras to go with it 
