44 replies to this topic

[descott12]

All,

What are your thoughts on this:

http://www.daystarfi...arkGemini.shtml

 

The advice has always been to "get the chromosphere model since it can be used to see proms" so I am not sure I understand the reasoning here. And it contains two etalons so it is $800 more expensive.

 

 

[jwestervelt]

Can't unsee the face...

 

 

 

Not sure how they designed the innards, but I think that this would hurt the thermal stability of the system if you have a physical sliding mechanism to pull the filters in and out of the optical path.  At the very least, this would tend to reduce the thermal efficiency or put a bigger load on the heating element.  :/    As opposed to using two filters, I'd have suspected that rigging something up to change the acceptance angle (and thus bandpass) would have been the way to go for simplicity as well as cost purposes, but clearly daystar engineers know this stuff better than I do.

Edited by jwestervelt, 25 May 2019 - 11:40 AM.

[descott12]

Can't unsee the face...

 

Haaa! Now I see and I can't unsee it either!

 

You make a good point about the temp changes.

[MalVeauX]

I just see Daystar trying to put the not-as-good etalons into this thing one (instead of producing the prominence model anymore), to get them off the shelf, instead of having boxes and boxes of Prominence models laying around. I have zero interest in this new Gemini model. I put it right next to the Sodium and Magnesium Quark options. Certainly not going to buy one for $2k new. I'd much rather see Daystar produce imaging class items other than the Quantum series to have something between the $1k Quark an the $5~6k~16k+ Qunatums that are geared towards imaging and not primarily focused on visual first, imaging second with them (Quarks that is). Not to be overly negative, I love my Quark, but the other Quarks in the series really are just an after thought in my mind, and there's nothing between a Quark and a Quantum; it would be nice to see imaging-class equipment instead of all this "visual" stuff that just gets used for imaging.

 

Very best,

Edited by MalVeauX, 25 May 2019 - 12:12 PM.

[BYoesle]

If you use a chromosphere model ( <0.5Å ) at less than the optimum f ratio of 45 or so, you very likely have the prominence bandpass of >0.6Å or greater.

 

The better choice would be to get the COMBO Quark chromosphere, use it by itself for a prominence filter at f10 or less.  Get a TeleVue Powermate 4x Barlow or a Baader or Beloptik telecentric lens system for the narrow bandpss the COMBO Quark chromosphere is capable of delivering at f30 +.

 

Christian Viladrich

[hopskipson]

I just see Daystar trying to put the not-as-good etalons into this thing one (instead of producing the prominence model anymore), to get them off the shelf, instead of having boxes and boxes of Prominence models laying around. I have zero interest in this new Gemini model. I put it right next to the Sodium and Magnesium Quark options. Certainly not going to buy one for $2k new. I'd much rather see Daystar produce imaging class items other than the Quantum series to have something between the $1k Quark an the $5~6k~16k+ Qunatums that are geared towards imaging and not primarily focused on visual first, imaging second with them (Quarks that is). Not to be overly negative, I love my Quark, but the other Quarks in the series really are just an after thought in my mind, and there's nothing between a Quark and a Quantum; it would be nice to see imaging-class equipment instead of all this "visual" stuff that just gets used for imaging.

 

Very best,

My feelings exactly!

 

Why no Quark Plus with a bigger blocking filter and better QC etalon with narrower bandpass? I'm sure more of us would be willing to upgrade

[BYoesle]

...it would be nice to see imaging-class equipment instead of all this "visual" stuff that just gets used for imaging...

 

Why no Quark Plus with a bigger blocking filter and better QC etalon with narrower bandpass? I'm sure more of us would be willing to upgrade

 

If they could they would. You have to be realistic about etalons. Back when H alpha filters for non-professionals came about, my 1976 DayStar ATM 0.7Å cost about $4k in inflation compensated dollars. I used it at f30 with a 40 mm RG630 ERF on an 80 mm f15 refractor, about equivalent to a double stacked PST today. And that was about it - the "University" model with even better contrast uniformity cost more - so today you have many more choices.

 

 

Contrast uniformity and good finesse are time consuming and costly to produce, whether it is in a mica or air spaced etalon. While these can be made, the costs make them a niche within a niche product. Most of the companies have had to increase sales and reduce production costs to stay in business with "consumer grade" products, and unfortunately there is no free lunch. The Quarks have none of the additional "qualification" requirements needed to produce a better finesse and contrast uniformity. Therefore reduced cost comes in general at the expense of reduced quality. To get a better "middle ground" filter would likely entail 80-90% of the cost to make an SE or PE filter, and the price point you are looking at would mean a loss to the company.

 

At least with the DayStar Quark vs. the Quantum SE or PE you know what you are getting ahead of time. If you want better quality, there is no middle ground - you really do have to pay for it. Be thankful there is the choice, as some of the companies seem to have only one choice of quality, and it can be a crap shoot.

[MalVeauX]

With the Quark for example, the etalon grinds transmission, as they all do, that's not going to change much due to the etalon itself. However, the blocking filter is a point that could be addressed since it's around 45% transmission. Even if the Quark was the same, but that transmission on the blocking filter was higher, it would be a nice break for imaging.

 

Regardless of it being a Quark, or a Solarmax or Lunt, or whoever's etalon system, they're all geared towards visual use for saftey purposes. I get that of course, we all do. But, it would be nice to have an imager's alternative with higher transmission that is not meant for an eyeball. Kind of like how there's photograde solar film (if you can find it.... sigh).

 

Very best,

[hopskipson]

If they could they would. You have to be realistic about etalons. Back when H alpha filters for non-professionals came about, my 1976 DayStar ATM 0.7Å cost about $4k in inflation compensated dollars. I used it at f30 with a 40 mm RG630 ERF on an 80 mm f15 refractor, about equivalent to a double stacked PST today. And that was about it - the "University" model with even better contrast uniformity cost more - so today you have many more choices.

 

DayStar sm.jpg

 

Contrast uniformity and good finesse are time consuming and costly to produce, whether it is in a mica or air spaced etalon. While these can be made, the costs make them a niche within a niche product. Most of the companies have had to increase sales and reduce production costs to stay in business with "consumer grade" products, and unfortunately there is no free lunch. The Quarks have none of the additional "qualification" requirements needed to produce a better finesse and contrast uniformity. Therefore reduced cost comes in general at the expense of reduced quality. To get a better "middle ground" filter would likely entail 80-90% of the cost to make an SE or PE filter, and the price point you are looking at would mean a loss to the company.

 

At least with the DayStar Quark vs. the Quantum SE or PE you know what you are getting ahead of time. If you want better quality, there is no middle ground - you really do have to pay for it. Be thankful there is the choice, as some of the companies seem to have only one choice of quality, and it can be a crap shoot.

I get your points, but I'm guessing engineering that Gemini cost a pretty penny too.  I just hope someone did their market research before coming up with that idea. I don't see myself looking to buy one.  I guess I'll save my pennies for an SE.

 

With the Quark for example, the etalon grinds transmission, as they all do, that's not going to change much due to the etalon itself. However, the blocking filter is a point that could be addressed since it's around 45% transmission. Even if the Quark was the same, but that transmission on the blocking filter was higher, it would be a nice break for imaging.

 

Regardless of it being a Quark, or a Solarmax or Lunt, or whoever's etalon system, they're all geared towards visual use for saftey purposes. I get that of course, we all do. But, it would be nice to have an imager's alternative with higher transmission that is not meant for an eyeball. Kind of like how there's photograde solar film (if you can find it.... sigh).

 

Very best,

I can see the lawyers and insurance advisers nixing an imagers only model.  I have some photo-grade Baader film marked in big letters PHOTOGRAPHY ONLY!! just to remind myself and others.

[MalVeauX]

Don't get me wrong, I certainly don't mean to poopoo on a new idea or new product. I am always happy to see new things coming to the solar market in general. I guess I just am underwhelmed at the Quark series in general as it keeps fleshing out, but none of them are home runs. I was real, real close to getting a CaH Quark. I certainly would not say no to a well priced Quantum of any kind if it were offered to me, but they're simply out of my budget and I really just don't need one. I'd love to see the big market guys drop some imaging-only devices. Daystar keeps outputting new things to the market, but mostly, they're entry level things centered on the Quark, which makes sense, due to price and the niche that it is.

 

I really just wish there was an affordable subscription to a "good seeing" plan available at any location.  

 

Very best,

[BYoesle]

 

Regardless of it being a Quark, or a Solarmax or Lunt, or whoever's etalon system, they're all geared towards visual use for saftey purposes. I get that of course, we all do. But, it would be nice to have an imager's alternative with higher transmission that is not meant for an eyeball.

 

Hi Marty,

 

The DayStar and Solar Spectrum filters are monolithic filter stacks and can not be altered to increase transmission. I think they could make a "imaging" version if they felt there was enough demand - it certainly appears there could be. And it shouldn't cost much more - if at all.

 

The air spaced etalon filter systems on the other hand can have some DIY improvements that increase transmission, but these filter systems cost more than the Quark to begin with, and require knowledge of each component and its function, and may require custom made mechanical components to be implemented correctly. And you have to be willing to experiment with things that will definitely void any warranty, and possibly frey your nerves in the process.

 

 

As always, should you or any of your IM Force be caught or killed, the Secretary will disavow any knowledge of your actions. This tape will self-destruct in five seconds. Good luck ...

 

This definitely isn't "quick, cheap, easy, and fun" as DayStar states for the Quark. Again, "cheap" and excellent and consistent quality are generally not found together.

Edited by BYoesle, 26 May 2019 - 11:55 AM.

[highfnum]

a somewhat old term "filtergram"  - cool 

[dscarpa]

 It will be interesting to read user reports but they'll not be coming from me.  Would much rather have a Quark you don't have to use with a Powermate  as I really don't like to be limited to narrow field Plossls.   David

Edited by dscarpa, 26 May 2019 - 01:32 PM.

[austin.grant]

Meh. I was disappointed in the lackluster performance of the QUARK Prominence and Chromosphere models, so this seems like a chance for me to be twice as disappointed at twice the price. The individual QUARK models were interesting because they were below the cost of decent standalone Ha scope. This new Gemini is not. For the same price, I can get a pressure-tuned Lunt LS60THa with the 12mm blocking filter and 2" crayford focuser, and I guarantee I'll be more impressed. 

Edited by austin.grant, 26 May 2019 - 06:08 PM.

[George9]

Too bad NEAF has passed. Would have been fun to try it out. I assume both filters stay at their temperatures when swapped out. So I could quickly A-B the two bandpasses to see for myself the benefits of the wider one (especially on a big scope with high-power spicules).

 

One possibility is to keep the chromosphere model on band and tune the prominence model to the blue or to the red to quickly look for ejection towards you or falling away from you. Yes you can do that with PT (and I do), but this would let you quickly search off band on a big scope.

 

Another possibility for me because I often double stack my Quark with an air-spaced etalon, I wonder if the wider one would produce a brighter view but still without the double limb. And flip to the narrow one for a darker but narrower view.

 

George

[ValeryD]

Too bad NEAF has passed. Would have been fun to try it out. I assume both filters stay at their temperatures when swapped out. So I could quickly A-B the two bandpasses to see for myself the benefits of the wider one (especially on a big scope with high-power spicules).

 

One possibility is to keep the chromosphere model on band and tune the prominence model to the blue or to the red to quickly look for ejection towards you or falling away from you. Yes you can do that with PT (and I do), but this would let you quickly search off band on a big scope.

 

Another possibility for me because I often double stack my Quark with an air-spaced etalon, I wonder if the wider one would produce a brighter view but still without the double limb. And flip to the narrow one for a darker but narrower view.

 

George

  One should not be disappointed if he sees a trace of double limb (DL) when observe with a double stack (DS).  Usually,  a DS already makes a view so much more contrasty vs a single stack (SS) view that a trace of a DL is not a problem at all.  An image brightness is more important with a DS view than a DL absence.  I'd better choose a DS when I see a trace of a DL  than a DS when I do not see a DL but can't use a higher power due to image darkness. 

So, for a DS I would choose a Prominence model with a brighter view.  Prominence models also usually look more uniform accross their FOV.

 

 

Valery

[Ben Cartwright SASS]

Has anyone used one of these yet?

[Spectral Joe]

a somewhat old term "filtergram"  - cool 

Still in common use, in scientific literature.

[Eddgie]

My concern would be that these would be that the Quark can stop tuning once the temps get above about 85 degrees.

 

The chromasphere model will still show Proms, but at 90 degrees, mine completely quit tuning.  

 

You know you are not tuning when the green light does not fully illuminate.   Now that does not mean the Quark won't still work, but it does mean that you may not get tight enough band pass to show much surface detail.

 

I had thought that is was just the effect of using such high power, but in the end, I learned that the Quark really does not handle heat well. I have read numerous reports of people saying that their Quark green light does not come on when tuning, and Daystar even says that this means that the temp is too high for the quark to work fully well.  Emphasis added by me...

 

If after 20 minutes of the same knob position setting the LED has not

turned green, the ambient temperature may be too hot or too cold for the Quark
to regulate the temperature. However, the filter may still be usable while slightly
mistuned and performance may not be affected.

 

This is a quote from Daystar Manual and while the use the word "may still be usable" but in my book that means "may not show you surface features with much detail."  That was my experience.  At 85 degrees, the Quark would stop giving green, but sometime would show some surface detail, but at 90 degrees, surface detail was poor...  Maybe it was my sample, but I know I read over and over that people say that their Quark does not turn green and maybe they still got good surface detail, but at 90, I could only really use it for prominences. (To be fair, it really did give excellent views of Proms, but so does my Lunt 80). 

 

My Lunt 80 works at 95 degrees as well as it works at 50.  I can see more surface detail in it than I ever saw in the Quark and it is only single stacked.  I live in a hot environment, and maybe I am the exception, but I would suggest that anyone that lives and regularly observes at 90 or above to look to a standard etalon design. These are temp stable even at 100.  I did a lot of research after the fact and found numerous cases where people said that they were not getting full green, and Quark is telling us right in the user's manual that this may mean that you are out of band, and again, my experience was that I was way out of band when it got over 90. 

 

I also of course get full disk and with binoviewers using zoom eyepieces, which was impossible with a similar sized scope using the Quark at f/30.  Since the standard zoom is 24mm at shortest focal length, you really can't get anything close to full disk.  You can use a faster focal lenght scope, but now you loose the ability to tune as tight as with an f/7 or f/8 scope. 

Edited by Eddgie, 28 July 2019 - 05:31 PM.

[Eddgie]

Meh. I was disappointed in the lackluster performance of the QUARK Prominence and Chromosphere models, so this seems like a chance for me to be twice as disappointed at twice the price. The individual QUARK models were interesting because they were below the cost of decent standalone Ha scope. This new Gemini is not. For the same price, I can get a pressure-tuned Lunt LS60THa with the 12mm blocking filter and 2" crayford focuser, and I guarantee I'll be more impressed. 

See my post above.  If you observed in hot weather, my bet is that the same thing that happened to me was happening to you. If you were not getting a full green light, my bet is your Quark was overheated and was not tuning.   Like Austin, ABQ gets pretty hot (94 in ABQ as I type this). I found that the Quark went way of band at 95. 

 

To the OP, I see it only got to 89 today in Charlotte, so maybe you would be OK and if you observer in the morning like many, you may be OK too.  If though you get in the 90s and you are going to observe mid day, you "may" run into tuning problems. 

[George9]

Both air-spaced and solid etalons can be affected by temperature. My revered pre-Meade 60mm Coronado never worked well over 90. My Lunt LS80 does. My Quark does.

For a solid etalon I think it just depends where the on-band temperature ends up. That is unit specific. If it happens to be low, then 90 could be a problem.

For an air-spaced unit, it is supposed to work, but it doesn’t always. Maybe it was the blocking filter and not the etalon.

George

[NorthernlatAK]

Temps where I live in summer rarely exceed 75°, although we did have one 90° record day this year. My typical temp range for early day temps throughout the year would be 20°-60°. I'm considering a quark due to budget and that it works well in cooler temps and in most refractors. With a 4" f/10 I should get good surface detail and an 80mm or smaller f/6ish I should see proms well. This is what my research has led me to conclude so far...

[Simon2940]

I have some test shots using the New Gemini 

 

I didnt do a flat frame for the Prom slider as I wasnt really thinking about as I was frying in the Sun.

 

This is shot using an Esprit 100 and a ZWO ASI174MM

 

 

 

[George9]

Thanks so much for sharing this. So which is which? The top seems narrower (second vs fourth and first versus third). I wonder if they will select an especially narrow etalon for the prominence module of the Gemini.

 

George

Edited by George9, 03 August 2019 - 03:49 PM.

[MAURITS]

Images looks oke.