80ed with daystar quark or Lunt 60 for visual

[Pig]

Perfect sense Stu.... That's why I have kept away from a reducer in the light path in hope that extra aperture will compensate, not because I am foresighted,  I simply thought I would keep faith in Lunt's dynamics of short focal lengths, as I believe they have solar sussed, even their 120 has a short focal length.

[Stu]

Perfect sense Stu.... That's why I have kept away from a reducer in the light path in hope that extra aperture will compensate, not because I am foresighted, I simply thought I would keep faith in Lunt's dynamics of short focal lengths, as I believe they have solar sussed, even their 120 has a short focal length.

Agreed, but it's that tricky combination of short focal length and optimum focal ratio with enough aperture which is hard to achieve.

Your Esprit is close, great on focal length but perhaps a little fast for max contrast?

In theory the perfect full disk scope would be 450mm focal length, f6.7 so 67mm aperture. That would give full disk at f29. I wonder what gets closest?

[Pig]

I think there are other contributors also Stu, IE Lower magnification aids detail, a 32mm combined with the Esprit really is better than in the Equinox regardless of speed, I wish you had given it at the outreach event

[Stu]

I think there are other contributors also Stu, IE Lower magnification aids detail, a 32mm combined with the Esprit really is better than in the Equinox regardless of speed, I wish you had given it at the outreach event

Hi Shaun,

I'm not doubting that for a moment, I stuck a 0.5 reducer after the Quark with a 32mm Plossl and the view was very nice, bright and detailed...but it was like looking down a straw and I don't enjoy that.

The Esprit deals with that very nicely but I think I remember you saying the contrast was a little lower? That can only be because it is operating at f21.5 rather than f29 surely?

All interesting stuff anyway [emoji3]

[Pig]

Yes your right Stu, but not with the 25mm SLV  The more we add to the posts the better we all get.

[Chinapig]

I think there are other contributors also Stu, IE Lower magnification aids detail, a 32mm combined with the Esprit really is better than in the Equinox regardless of speed, I wish you had given it at the outreach event

Apologies if this comment is fractionally off-topic, but I've read your various posts about the combination of Esprit 80 with the Quark with much interest. I'm using mine with an Equinox 80, and the wee Starwave 70ED (420mm/f6) - the Equinox delivers slightly better detail, as you might expect, while the 70ED achieves neat FD views, with a bit to spare. Swapping H-alpha and white light between the two is keeping me pretty happy. However, I'm considering a smallish triplet, with general AP in mind and, given the comments on the Esprit 80 with the Quark, I'm curious as to how the Esprit 100 triplet might fare. With its extra aperture, but at f5.5, do you guys reckon this would be a viable partner for the Quark?

Any comments and predictions would be much appreciated.

Thanks folks.

Cheers

Simon

[Pig]

Simon,

I have fell for my Esprit big time  and if you also have AP capability that's a bonus. F5.5 will be fine as it isn't far from your Equinox at F6.3 (the 80mm is F5 and works just fine) However, you will not achieve a full solar disc without tinkering around.

[Chinapig]

Shaun - many thanks for the feedback, very much appreciated. Yeah, understood re full disc, and not TOO bothered about that. Glad to hear how much you like your Esprit. Very encouraging, and definite food for thought!

Cheers

S

[Pig]

Your most welcome

[michael.h.f.wilkinson]

One thing to note is that the bandwidth of the etalon in the Quark is a function of the focal ratio at which it is used. With my Solar Spectrum etalon, there is a warning not to use it faster than F/25, and that F/30 or higher is where the performance is best. In an F/5 scope the etalon of the quark is working at F/21.5, which widens the pass-band considerably. This would help seeing proms, but reduce constrast on the disk, just as is observed. I have seen excellent results using a Quark with an ST80, but I think they stopped that down a bit.

[edit, just spotted Stu's post above, where he reaches the same conclusion]

With the Solar Spectrum set-up, I have essentially given up on using that for full disk viewing in the APM 80mm. I will just use it for detailed views, but might try it in the ST80 with a 50-60mm aperture stop to keep the focal ration up.

[Luke]

Hmmm, well with things lined up I have no complaints about contrast at F6. Shaun is happy at F5. Stu has great contrast at F5.9. And Daystar says for fracs from F4 to F9. So personally I would not worry too much about F5 if that speed or focal length had some appeal for me that might outweigh better performance at around F7. Shaun's Esprit 80 is a real tempter for me, it would sound perfect for my grab and go untracked imaging. But must resist, must use my 'briefcase telescope' for grab and go. I am not at all tempted :grin:

[Pig]

There is more to it than meets the eye !!!!!  or maybe there isn't, no pun intended. The Esprit is F5 (21.5) the Equinox F6.3 (26.8) The Equinox gives better surface detail with the 32mm TV and the Esprit gives the best detail overall view with the 25mm SLV and a full disk. Prominences are spectacular in both scopes with both eyepieces 

There is clearly production variation to consider..... stick within the guidelines and you wont go far wrong

[Stu]

Shaun, there certainly is!

I've just been trying the Quark in my Tak 76 with the 32mm Plossl. System focal length is 32.25. The contrast is very nice, on a par with the 60 but with higher mag and better detail.

But..... I then retried the x0.5 focal reducer in the eyepiece and, remembering that that affects the eye relief, took off the extender guard. Hey presto, lower mag, much better contrast and really nice detail!! Without the eyeguards it is much easier to see more of the field of view out to the fieldstop, and there are fewer reflections being close to the exit lens. Not full disk obviously (570mm focal length), but enough to be able to take in large parts of the disk.

I'm wondering whether something like a 25mm with focal reducer would be even better.

My conclusion.... That the focal ratio through the Quark is important for contrast, as is low magnification as you have been saying. It got through my thick skull eventually [emoji6][emoji6][emoji3][emoji3]

Lovely views now, seeing a little iffy still but very nice proms plus plenty of surface detail.

Stu

[Pig]

LoL thick is one thing I would not tag onto you Stu.... your very helpful and knowledgeable, but I wont go on too much as you will get big headed

All this switching and experimenting with the Quark with different scopes and different eyepieces in different combinations has sent me cockeyed and it is also a little easy to get lost with what and which was best

I took delivery of the continuum filter yesterday and used it today.... It makes the sun a very nice colour and appears to enhance the spots detail, However, time will tell.

I couldn't get the Esprit to focus when putting it before the diagonal.... it will require an extension tube. ( now looking to order one)

What I did see looked pretty amazing, though but its hard to tell until it focuses properly, it was like smelling good food whilst its cooking but the taste is what counts

[Stu]

Good stuff Shaun. The Continuum works well, relatively subtle but definite improvements in faculae and granulation.

I think I'm finally getting there with my Quark. Understanding this focal ratio piece is key, combined with keeping the mag down.

I've just tried two more combinations, an 18mm BGO with 0.5 reducer, and the Leica Zoom, again with reducer. Field of view apart, the BGO had it in this instance and I think it works really well, effectively a 36mm ep. Perhaps the 40mm Plossl has something to offer after all? Will give it a try again.

Anyway, I'm delighted with the views this afternoon and really feel I'm getting the best out of it now, lovely proms and good contrast on the surface detail.

I'm sure the Esprit is ultimately the way to go, but I don't have that sort of cash free currently so have to be a little incentive [emoji3]

Thanks for your input Shaun, Michael and others.

Stu

[Al.Grant]

LoL thick is one thing I would not tag onto you Stu.... your very helpful and knowledgeable, but I wont go on too much as you will get big headed

All this switching and experimenting with the Quark with different scopes and different eyepieces in different combinations has sent me cockeyed and it is also a little easy to get lost with what and which was best

I took delivery of the continuum filter yesterday and used it today.... It makes the sun a very nice colour and appears to enhance the spots detail, However, time will tell.

I couldn't get the Esprit to focus when putting it before the diagonal.... it will require an extension tube. ( now looking to order one)

What I did see looked pretty amazing, though but its hard to tell until it focuses properly, it was like smelling good food whilst its cooking but the taste is what counts

Although not Quark related (so a little off topic)

This might be worth a quick read about using the continuum.

http://www.schursastrophotography.com/solar/Articles/solararticle3.html

It compares differences of solar imaging with different 'green' filters and with/without IR blocking filters.

Conclusions seem to be that for visual there is little benefit, but for imaging then solar filter + UV/IR blocker + continuum seems to be best combo.

Thanks to all for the info about Quark & equinox.  Now I just need the thing to arrive!

Al

[Stu]

Although not Quark related (so a little off topic)

This might be worth a quick read about using the continuum.

http://www.schursastrophotography.com/solar/Articles/solararticle3.html

It compares differences of solar imaging with different 'green' filters and with/without IR blocking filters.

Conclusions seem to be that for visual there is little benefit, but for imaging then solar filter + UV/IR blocker + continuum seems to be best combo.

Thanks to all for the info about Quark & equinox. Now I just need the thing to arrive!

Al

Al, yes that's correct, the continuum does not block IR so for imaging a cut filter really helps.

What's occurring? You've got me talking about imaging now!!!!! [emoji6]

[Stu]

One thing to note is that the bandwidth of the etalon in the Quark is a function of the focal ratio at which it is used. With my Solar Spectrum etalon, there is a warning not to use it faster than F/25, and that F/30 or higher is where the performance is best. In an F/5 scope the etalon of the quark is working at F/21.5, which widens the pass-band considerably. This would help seeing proms, but reduce constrast on the disk, just as is observed. I have seen excellent results using a Quark with an ST80, but I think they stopped that down a bit.

[edit, just spotted Stu's post above, where he reaches the same conclusion]

With the Solar Spectrum set-up, I have essentially given up on using that for full disk viewing in the APM 80mm. I will just use it for detailed views, but might try it in the ST80 with a 50-60mm aperture stop to keep the focal ration up.

Hi Michael,

Following on from this, is the concept of an optimal focal ratio valid eg f29, or is it simply a case of the higher the better. Obviously there are other reasons not to go too high but from a contrast perspective would say f35 be better than f29?

[Pig]

I had a shock of my life just now I thought the Esprit focuser had stopped working.... I couldn't get the quark to focus no matter what I tried, in and out with the focus travel I went, I even used the fine focus knob for the whole travel, both ways.... and nothing !!!!!

I couldn't understand it as it was fine earlier today, the only thing I had done that may have disturbed something was the try the Quark before diagonal... I was at a loss and almost blubbering.

Then the light bulb came on and I looked at the eyepiece, I had picked up the 2.5mm SLV and not the 25mm  what a plonker............

[Stu]

Funny :-)

Can you see that flare I saw? Fairly central?

[Pig]

Yes Stu...not far off facing Earth !!! very bright and active, almost glistening

[Stu]

It's dimmed down since half an hour ago, was very bright then.

[Snaxmuppet]

With the Solar Spectrum set-up, I have essentially given up on using that for full disk viewing in the APM 80mm. I will just use it for detailed views, but might try it in the ST80 with a 50-60mm aperture stop to keep the focal ration up.

Michael, did you try with the ST80?

How did it go?