Why my Quark always refused to work...

[krakatoa1883]

Since I purchased my Quark chromosphere in 2014 I realized that it is certainly not among the best units, I have always been forced to use of heavy sharpening and contrast masks to make chromosphere details visible, and my results have often been modest. As the etalon performance in Quark units can be very different from each other I thought my one have a too large BP or some defect in the tuning system. Eventually I modified my achromat with a Lunt PT module and this is my current setup, however I still use the Quark with my travel set. Today I casually discovered why my Quark performances were so poor.

The following is a raw, not processed, image of AR12738 I have taken this afternoon with my Quark and its original blocking filter

quark with original bf.jpg (18.72 KiB) Viewed 8346 times

and this is a raw image of the same region after the original BF has been removed and replaced with a Lunt BF1200

quark with BF1200.jpg (27.66 KiB) Viewed 8346 times

OK, I am going to replace definitively the BF

[marktownley]

You can find the replacements here https://www.andovercorp.com/products/ba ... 600-699nm/

Part No. 656FS02-12.5

I replaced mine with the 25mm version...

Try a circular polariser too between the camera and quark, if the waveplates in the etalon are not perfectly aligned any 'leakage' will be polarised with respect to the primary output so it's contribution can be eliminated with a polariser. Any leakage like this will also reduce contrast.

[krakatoa1883]

Thanks Mark, I am contacting the Italian representative of Andover to purchase the replacement. How did you mount the 25mm for using with it your Quark ?

[marktownley]

Hi Raf,

I mounted the 25mm andover in the cell from a real cheapie barlow lens (throwing the lens away) and then mounted that on a 2" to 1.25" filter adapter https://www.365astronomy.com/365Astrono ... apter.html I then replaced the 2" snout on the Quark with a slightly longer one and screwed it all together.

Mark

[Valery]

You can find the replacements here https://www.andovercorp.com/products/ba ... 600-699nm/

Part No. 656FS02-12.5

I replaced mine with the 25mm version...

Hi Mark,

What was the reason you have replaced it in your Quark?


Valery

[pedro]

My Chromosphere Quark was send back for replacement/repair. I will get it back this month. I guess this is not a surprise to most of us...

[marktownley]

You can find the replacements here https://www.andovercorp.com/products/ba ... 600-699nm/

Part No. 656FS02-12.5

I replaced mine with the 25mm version...

Hi Mark,

What was the reason you have replaced it in your Quark?


Valery

I wanted the larger versions so it sat higher in the exit beam from the HaT, and, I also figured with 2 blocking filters (based on experience) that one would have a higher transmission than the other, which it did, and it was the larger one that let more light through.

[Montana]

Mark, you would do well setting up a business making custom filters and repairs

Alexandra

[krakatoa1883]

Looking in my image archive I discovered several not-too-bad images taken with my Quark and its original BF, for example like these

sun20170821_Ha_AR12671.jpg (62.84 KiB) Viewed 8103 times

AR12651_20170422c.jpg (29.92 KiB) Viewed 8103 times

It therefore seems that for some reason the BF degraded only recently although I have always been careful not use my Quark without a UV/IR cut filter or even a Baader D-ERF in front of it.

Has anyone experienced the same problem ? Is there any alternative to the original BF that I can use ? I have tried a Lunt B1200 which is fine for imaging but too dark for visual.

Thks

[pedro]

I received a brand new Chromosphere Quark and I will test it soon. Hope this one will perform better

[marktownley]

Fingers crossed for you Pedro!

[krakatoa1883]

At first my Quark wasn't bad, something happened to the BF later... still to understand what...

[krakatoa1883]

Finally the new BF from Andover arrived and indeed it made a huge difference, so my Quark is now returned as new. I am very happy because the etalon of my unit is good and very uniform and a degraded BF made it almost useless. The replacement BF also totally cured the problems I had with front ERFs and I can now use of my Baader D-ERF without image degradation.

I wonder what the reason might have been why the original BF degraded. I examined it under my stereo microscope without noting anomalies on any of the surfaces. I think of a possibile overheating while inadvertently using it without ERF.

The following is an image of today (2019-06-28) E limb with my Skywatcher 72ED, Baader 35nm filter as ERF and Quark. It was so hot that my Quark got tuned without current

andover new.jpg (76.3 KiB) Viewed 7694 times

thermo.jpg (54.79 KiB) Viewed 7694 times

While waiting for the replacement I made some experiments by using of a Baader 3.5nm H-alpha filter in place of the defective BF. Well, for prominences it worked fine, it actually transformed the chromosphere Quark into a prominence one, which is very useful for faint features.

2019-06-16-1253-RB-Halpha-flame.jpg (20.05 KiB) Viewed 7694 times

2019-06-14-0815-RB-Halpha-proms.jpg (15.24 KiB) Viewed 7694 times

[marktownley]

Glad it is working again for you Raf! Hope it doesn't get too hot for you.

[Montana]

Wow!! these are fantastic prom shots
In Spain we only hit 37.5 degrees on the thermometer
Alexandra

[axion]

Hi Raf,

I mounted the 25mm andover in the cell from a real cheapie barlow lens (throwing the lens away) and then mounted that on a 2" to 1.25" filter adapter https://www.365astronomy.com/365Astrono ... apter.html I then replaced the 2" snout on the Quark with a slightly longer one and screwed it all together.

Mark

Hi Mark and All,

it is a very interesting discussion and I have a similar problem - the images I am getting with my Quark filter are not too sharp. For example,
https://flic.kr/p/2gy1i6u I am completely new to solar imaging so there could be other issues... I had hard time focusing as well.

As I understand the problem could be with the BF in the Quark. I have ordered Andover 25mm 656FS02-25 which is coming in few days, the plan is to mount this 25mm filter into an empty 1.25'' filter cell and attach it to the Quark. Do you think it will work? It should right?

Also, I've heard here the word 'replacement', it is possible to disassemble the Quark and replace the existing BF with the new one? With my original plan I will have two BF filters - one in the Quark and the external one, will it work?

thank you,
Roman

[marktownley]

You would need to take the little 12.5mm one out of the base of the telecentric in the quark, it just has a retaining ring. 2 blocking filters would make it awfully dark!

Welcome to the forum btw!

[axion]

Thx!!! I have not thought about removing the original BF until I found this thread, now it seems like a good idea.

I'll try to be active on this forum - have too many questions, xD

Thank you again
Roman

[krakatoa1883]

Replacing the BF may help however incorrect tuning and poor seeing may also lead to obtain ill-defined images. Hope your new BF will improve things.

[Liam]

My yesterday broke. Probably messed up with the setting and hurt something, I do not know. I was so not satisfied with the result that I lost my temper, did not expect this: (

Regards, Liam.
My blog.

[hopskipson]

Hi Raf,

I mounted the 25mm andover in the cell from a real cheapie barlow lens (throwing the lens away) and then mounted that on a 2" to 1.25" filter adapter https://www.365astronomy.com/365Astrono ... apter.html I then replaced the 2" snout on the Quark with a slightly longer one and screwed it all together.

Mark

I looked at my Quark and if I remove the blocking filter it only gives you a little diameter increase. Am I missing something to utilize the larger blocking filter? Can you please provide pictures of your mod.? Thanks

[hopskipson]

Hi Raf,

I mounted the 25mm andover in the cell from a real cheapie barlow lens (throwing the lens away) and then mounted that on a 2" to 1.25" filter adapter https://www.365astronomy.com/365Astrono ... apter.html I then replaced the 2" snout on the Quark with a slightly longer one and screwed it all together.

Mark

I looked at my Quark and if I remove the blocking filter it only gives you a little diameter increase. Am I missing something to utilize the larger blocking filter? Can you please provide pictures of your mod.? Thanks

Hi Mark
Can you please explain how this will increase the size of the blocking filter significantly? When I took out the original blocking filter I only see a small increase in the opening into the telecentric. Am I missing something? I'm afraid to take apart my Quark when I have no idea what I'm doing. Pictures would really be helpful. Thanks!!

[marktownley]

Hi. Seems to be some confusion over why I did what I did. Firstly, I gambled on the 2 filters having different transmissions, even though they are both on paper supposed to be the same, and, indeed, it turned out the larger filter does let through more light. Secondly, the larger filter sits higher in the light cone, so has less thermal loading than the original smaller filter.

Why do you want to take your Quark apart? Is there an issue with it?

[hopskipson]

Hi. Seems to be some confusion over why I did what I did. Firstly, I gambled on the 2 filters having different transmissions, even though they are both on paper supposed to be the same, and, indeed, it turned out the larger filter does let through more light. Secondly, the larger filter sits higher in the light cone, so has less thermal loading than the original smaller filter.

Why do you want to take your Quark apart? Is there an issue with it?

Thanks for the reply, Mark! There are no issues with the my Quark (Knock on wood!), I just thought you were using a larger blocking filter to gain more area to increase the field of view. Now I understand it was to let more light in than the original Blocking filter. Still would be nice to see how you mounted the new blocking filter.

[Radon86]

Hi Krakatoa,
I am a solar imager in London since March 2019.
I got a Quark chromosphere at a sale in an Astronomy show! The upper compression ring on the eyepiece holder was slightly faulty. Visually, I can see decent detail though, with surface and proms seen well.
I have only got round to processing my video files, trying to learn the software, and also getting flats to work.
Focusing without sunspots seems hard. Also wind and faulty tripods and cloud and ? jetstreams ( how do you find out jetstream data?)

I am also wondering if my Quark chromosphere is faulty. Are your better images stacks ? How many frames did you stack or is it just 1 frame?
What about processing eg gamma, deconvolution, unsharp masking etc?
I use a 70mm Refractor, uv-ir filter, ASI 120mm-S with a slow usb-2 laptop. I wonder if its my Quark, or is it poor seeing conditions e.g. high clouds, jet stream interference, or poor focusing.

I have only started recently, a few imaging days. I had technical problems with my tripod earlier, but am ironing out problems.
I will try a more recent solar image, but wonder if its because of my poor equipment? Your latest Image with the new Quark looks really nice - is it a single unprocessed .jpg? How many frames did you need?

Thanks, Magnus.