|
Post by johnno on Sept 8, 2014 16:50:11 GMT
Why is there a difference in price? you can buy, say a 50mm solar scope cheaper than buying a 50mm filter kit. I would of thought the scope would be more expensive but it seems to be the other way round.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Sept 8, 2014 19:38:26 GMT
A basic solar telescope is a metal tube with an objective at one end, a quite small etalon inside, a focuser and a small blocking filter at the other end. Objectives are not very expensive, the tube costs peanuts, the standard focuser is quite cheap. The main cost is the blocking filter and the small etalon. When you buy a filter kit or add a second filter to double stack, you are buying a much larger etalon which costs a lot more to make. Consider the PST. The objective is 40mm but the internal etalon is only 20mm. The Lunt 60T has a 60mm objective but a 35mm internal etalon. When you double stack a PST you are paying for a 40mm etalon and likewise with the Lunt you are buying a 60mm etalon.
Etalons apparently are not cheap to produce so with the larger etalons, more special glass is needed and the accuracy and tolerances to which they are made are much more demanding.
This is all part of the reason that we modify small solarscopes to work with much larger objectives. You can build a 20mm PST etalon into a 150mm refractor for a tiny portion of the price of a 150mm solarscope that has a much larger etalon inside.
|
|
|
Post by Rick in NWArk on Sept 8, 2014 20:34:25 GMT
Wow good stuff Allan, thank you! I dont know much about solar scopes and I appreciate that insight.
I'd like to do some solar astronomy, but I'm very cautious about it.
|
|
|
Post by johnno on Sept 8, 2014 20:59:53 GMT
Thanks Allan, I didn't realize that a 50mm solar scope didn't have a 50mm etalon, I guess you've seen the ad on 'uk buy and sell' for that filter set and the pricing what threw me, I was going off the price of a new 50mm solar scope and the price of a new 50mm filter set and couldn't work out why there is about a £500 price difference.
cheers Allan
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Sept 8, 2014 23:44:51 GMT
Yes Johnno, the double stacking filters are one big chunck of glass. I see from current ads that the new Lunt LS50THa with a B600 blocking filter for imaging is the same price as the double stack etalon filter on its own. Now you know why.
Looking at the 'UK buy and sell' advert, you get the 50mm filter, with a couple of scope adapters and a B1200 blocking filter. I recently bought a B1200 and it cost me £745 new. So I reckon he is selling that filter set for just a fraction over half price. not a bad deal.
|
|
|
Post by johnno on Sept 9, 2014 10:56:52 GMT
So am I right in thinking that if I had that filter set and correct adapter it would simply just fit on my scope with no further modifications.
I would just fit the etalon on the front and the diagonal and i'm good to go.
|
|
|
Post by johnno on Sept 9, 2014 11:07:20 GMT
Managed to borrow a Solarmax 60 the other day to try some imaging for a couple of hours, and it was a lot of faffin about with not knowing what to do. Tried it with the 2000p and the little inova both camera's gave different results, the 2000p seemed to give a better image for the prominences and the inova for the surface.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Sept 9, 2014 12:14:16 GMT
So am I right in thinking that if I had that filter set and correct adapter it would simply just fit on my scope with no further modifications. I would just fit the etalon on the front and the diagonal and i'm good to go. Yes, that's all you have to do. You would need an adapter that fits over the front objective of the ED80 and the filter screws into it. Then replace your diagonal with the B1200 blocking filter and away you go. There are some obvious safety precautions to adhere to. Cover the objective of the finder scope, or simply remove it, or the sun will melt the ep. NEVER look through the scope with the blocking filter or etalon filter removed or your EYE may melt. Always use both parts together.
You have to bare in mind that any refractor you fit the etalon to, will become a 50mm refractor . So your ED80 @600mm F7.5 becomes a lunt 50 @600mm F.12. You can also add barlows to the cam for closer views or focal reducers for wider views. Same as normal. Mono cams give better results for solar, but I have had very good views with the SCB4000.
|
|
|
Post by johnno on Sept 9, 2014 13:07:59 GMT
Allan what would you suggest, I fancy getting that new lunt 50 when it comes out or a filter kit, but the kit is pushing my Wonga over the top, by the time I've bought a adapter it will be over a grand.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Sept 9, 2014 13:57:13 GMT
Its a very difficult choice Johnno, and one I had to make when I went into solar. The filter kit is more versatile in that it can be used with any refractor, but the new pressure tuned Lunt 50mm should give a better view straight out of the box as it has been designed to operate in its current form. It should show a very evenly illuminated full disc and should be very easy to use. It should operate just like my lunt 60mm. The pressure tuned filters always work slightly better than tilt tuned filters in my opinion, but the tilt tuned filters still work very well. you notice that I have used a lot of 'should' in my reply as there is not much info on it at the moment. As I said, I had this same decision to make a couple of years ago......I bought the pressure tuned Lunt60T and then added the 60mm double stack filter, and then another B1200 diagonal so that I could have everything and in any configuration I wanted. I also modified my Lunt 60T to work with larger scopes (as in my profile pic) but that is another story.
Ultimately the decision is yours johnno, but I have to admit, the new lunt is very tempting for the price. If you go that route, get the B600 blocking filter as it will allow better imaging.
|
|
|
Post by johnno on Sept 9, 2014 15:26:08 GMT
cheers Allan, if I went for the lunt 50 it would be the B600 version. will hang on and see the reviews, no doubt all the first batches have been taken so no great rush to dive in.
bit of a mine field like when your first start in astronomy, never get it right first time round.
|
|
|
Post by johnno on Sept 11, 2014 13:44:01 GMT
looks like the new lunt 50 is delayed again, maybe October before being shipped out.
|
|
|
Post by Dragon Man on Sept 11, 2014 15:22:15 GMT
looks like the new lunt 50 is delayed again, maybe October before being shipped out. They've probably been waiting for the sun to come out to test it
|
|
|
Post by johnno on Sept 13, 2014 13:19:16 GMT
now its just less than half price,
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Sept 13, 2014 15:08:14 GMT
I'd be surprised if no-one takes it at that price. I think the new Lunt (when it arrives) and the new Quark are having an impact on sales of used solar scopes and filters. If I didn't already have a second B1200 diagonal I would have it and sell on the 50mm filter.
Hang on for the new Lunt Johnno. I think it will work out better. Its pressure tuned and I'm sure it will perform better for full discs.
|
|
|
Post by johnno on Sept 14, 2014 9:56:58 GMT
Cheers Allan think I will hang on but its been a close call
|
|