Help with my new quark, is this normal?

[Nik271]

Dear SGLers of the brightside, 

Can you help me to check if this issue in my new quark is normal?

First let me say that in the three times I've used it the views are great, I can see prominences on the limb and filaments on the disk, with a 70/420 ED refractor. Today I tried it with binoviewers and the views were even better, very 3D. But I don't have anything to compare it with and I noticed this disturbing issue:

It all started with one of the 30mm Plossls that came with the binoviewers, I decided to put it directly in the quark becuase one special thing about these Plossls is that to minimize the light path they don't have a long barrel and go 'all body in'. As a result the focal plane of the EP is very close to the optical window. I was actually hoping to maximise the field of view. But what I saw superimposed over the focused image of sun looked horrible: some fibrous mesh of strands, a bit like looking through a coarse thin curtain. There were also 4 or 5 bright orange spots, where I think coating is missing and the photosphere is leaking through.

Nothing of this actually shows on inspecting the outside red window (on the eyepiece side) in normal light, it looks spotless.

After I saw this issue I noticed that with my other normal 32mm and 20mm plossls I can detect slight uneven illumination in the field in the places where the bright dots are. I attach photos and a video I made with my phone camera directly  at the optical window without an eyepeice in the holder. The orange blob is the sun illuminating the red window from below. 

I believe the fibrous things I see must be the sheet of mica in the etalon. I understand that the quarks are entry level product and there is no expectation of uniformity and I'm happy with that for the price. But what about the 4-5 orange dots, they look like mini scratches on the inside. So far they don't affect the view (I think) but I'm concerned with they could increase in the future. 

What do you think, is this normal quality of a quark? Does yours show similar uneveness? One easy way to check is when focused on the sun to remove the eyepiece and look at the red window as the sun disc is showing through, any defects become very noticeable. Any opinion is welcome.

 

 

Nik

 

 

 

 

Edited March 23, 2023 by Nik271
typos

[Elp]

Did you try and rotate the eyepiece and look again to see if the features had all rotated? From your video, it looks like the eyepiece is the culprit until further investigation. Also, not all plossls are created equal for HA viewing, I've found the majority which you expect to be good, aren't.

[Nik271]

All images are without an eyepiece in the quark, directly at the image of the sun through the etalon. But yes I tried rotating the Plossl it had no effect.

[Carbon Brush]

I have never used a Quark. Only a couple of PST & LS60 so not an expert opinion. Free advice is worth what you pay, etc.

I have seen internal reflections in otherwise good eyepieces, though these are obvious by their movement when you move the scope a little.
To me your 'fibres' are very well focussed items somewhere in the optical train.

Are you able to put the Quark in a different scope?
I'm thinking here that by using different lenses either side of the Quark, you may an idea of the conditions to cause the strange effect.
If you conclude the Quark is generating the problem, you are in a position to ask the retailer to sort it out.

HTH, David.

[Elp]

What I would say, it certainly isn't normal. Dead areas off band maybe, not what you're seeing. I'd be concerned about the bright spots too whether they're filtering out the sunlight. Is the issue intermittent or is this how it is always on all temperature settings?

[Peter Drew]

I can't help feeling that this is similar to shining a torch on to an aluminised surface which always makes things look worse than they are.  If the views using the Quark are as good as described then the unit probably falls within the manufacture's entry level parameters.   🙂

[Nik271]

48 minutes ago, Peter Drew said:

I can't help feeling that this is similar to shining a torch on to an aluminised surface which always makes things look worse than they are.  If the views using the Quark are as good as described then the unit probably falls within the manufacture's entry level parameters.   🙂

I agree as long as the views are good I'm reluctant to return it, perhaps I'm worried over nothing. Inside the Quarks are so many layers of filters I don't expect it to look perfect under the harsh light of the sun.  But then I replaced my Baader solar film immediately i noticed it developed small dead spots for safety reasons.

I think I should write to Daystar, they should know if this is outside normal.

[Nik271]

I found this test afocal image of a quark filter by Christian Viladrich:

http://astrosurf.com/viladrich/astro/instrument/spectro/Quark/Quark-1/Quark-1-Alim-9h-23juin2022-Fluo55-collimate-105macroS-DSC-2171.jpg

It looks just as bad as mine and Christian says this is not unusual for mica etalons. So I guess I'm being too paranoid and this picture is normal. Anyway I did write to Daystar today and I will report when (if) they respond.

 

[Highburymark]

Nik - I will try and PM you about this this weekend - just super busy with work at the moment so don’t have time right now. I have some experience that’s relevant.