Search found 2989 matches

by Valery
Mon Oct 15, 2018 3:43 am
Forum: This is SolarChat !!
Topic: Help Diagnose an SCT?
Replies: 24
Views: 373

Re: Help Diagnose an SCT?

And something else. Why would a 8 inch SCT be better than a 6 inch refractor? You win two inches, but you loose a lot because of the central obstruction. So by default, contrast is better in a refractor. This is a mistake in the case of ultranarrowband imaging! For planetary observing this is corre...
by Valery
Sun Oct 14, 2018 2:42 pm
Forum: This is SolarChat !!
Topic: A Sunrise in there somewhere.
Replies: 8
Views: 125

Re: A Sunrise in there somewhere.

So impressive, Derek!

So, where is this?
by Valery
Sun Oct 14, 2018 3:35 am
Forum: This is SolarChat !!
Topic: Help Diagnose an SCT?
Replies: 24
Views: 373

Re: Help Diagnose an SCT?

I slightly processed Marty's image of Copernicus crater and took the crop of this crated from the image taken with 260mm Vixen reflector. Here they are. Looking at the smallest details at the crater floor I can conclude that SCT keeps equality in resolution. All the differences in image quality can ...
by Valery
Sun Oct 14, 2018 2:50 am
Forum: This is SolarChat !!
Topic: 10-13-2018 Ar2724 - Triple iron arch's
Replies: 4
Views: 83

Re: 10-13-2018 Ar2724 - Triple iron arch's

What this (this sample) filter exact data? What is the telescope and full imaging train?

I see the arc in the center near the spot. But it is difficult to say what the real nature of it.
by Valery
Sat Oct 13, 2018 3:01 am
Forum: This is SolarChat !!
Topic: Help Diagnose an SCT?
Replies: 24
Views: 373

Re: Help Diagnose an SCT?

Marty's image of Copernicus shows some star-like bright points (summits of mounts or rocks) on a black background. They look a bit oval (may be atmospheric dispersion, may be a small astigmatism, but think that this is AD) and represent Airy disk. We can see even first diffraction rings around them....
by Valery
Fri Oct 12, 2018 10:41 am
Forum: This is SolarChat !!
Topic: Help Diagnose an SCT?
Replies: 24
Views: 373

Re: Help Diagnose an SCT?

Marty, I am optimistic about this your scope. Smaller craters around Copernicus makes me optimistic. I think that the only problem is that your scope is inside the building which can and does impact on the seeing as the source of turbulence of two kinds: convections and air flows disturbations. The ...
by Valery
Fri Oct 12, 2018 10:27 am
Forum: This is SolarChat !!
Topic: Winter project: CaK doublestack
Replies: 23
Views: 300

Re: Winter project: CaK doublestack

I know I would have to go bigger in the end. But first let me master this with a relatively small telescope (150mm f/8 Skywatcher). Bart, You are a prisoner of illusions. If your 150mm F/8 achromat is nully corrected at a green light, say, at 530-546nm then Strehl ratio at the CaK line 393,4nm is o...
by Valery
Fri Oct 12, 2018 10:06 am
Forum: This is SolarChat !!
Topic: Winter project: CaK doublestack
Replies: 23
Views: 300

Re: Winter project: CaK doublestack

TheSkyBurner wrote:
Fri Oct 12, 2018 6:22 am
Valery wrote:
Fri Oct 12, 2018 6:01 am
Yes, I do use SAFIX after ERF

I don't know what is your 150mm refractor to tell you wha to do.


Valery
150mm x 2250mm F/15
If your objective is null corrected at 532nm (530 - 546nm range), then at 3933,7A it
should has 0,94 Strehl and so, no corrector needed.

Valery
by Valery
Fri Oct 12, 2018 6:01 am
Forum: This is SolarChat !!
Topic: Winter project: CaK doublestack
Replies: 23
Views: 300

Re: Winter project: CaK doublestack

Yes, I do use SAFIX after ERF

I don't know what is your 150mm refractor to tell you wha to do.


Valery
by Valery
Fri Oct 12, 2018 2:35 am
Forum: This is SolarChat !!
Topic: Winter project: CaK doublestack
Replies: 23
Views: 300

Re: Winter project: CaK doublestack

Double or triple or quadro stack will not gain enough in sun appearance in Ca K at a small scale. Good Lunt CaK filter is enough for small telescopes. The only gain will be prominences. The only real gain from DS or TS can be obtained only at super granulation cells level. However this require a tel...
by Valery
Thu Oct 11, 2018 6:06 am
Forum: This is SolarChat !!
Topic: A very special prom on Oct 10
Replies: 27
Views: 404

Re: A very special prom on Oct 10

Hi, Skyburner Thanks for your suggestion about using an Ha filter in the optical train. I see that both Baader and Astronomik have a 7nm Ha filter that's ok pricewise. I'm not entirely clear on why the filter should be ahead of all the optics at the back end of the scope. That puts it in a very hig...
by Valery
Thu Oct 11, 2018 12:50 am
Forum: This is SolarChat !!
Topic: A very special prom on Oct 10
Replies: 27
Views: 404

Re: A very special prom on Oct 10

Prominences with 9.25" scope are so impressive! 0,63x reducer makes a sense.


Valery
by Valery
Wed Oct 10, 2018 8:24 pm
Forum: Solar Scope Modifications
Topic: PST Mods... but, why not a 40mm SolarMax Mod?
Replies: 13
Views: 236

Re: PST Mods... but, why not a 40mm SolarMax Mod?

Thanks Valery, Very interesting. A PST etalon & Quark together serves as a double stack and has a blocking filter without having to get anything other than the mounting hardware. I'm curious how it performs, if folk are doing that, and what kind of transmission it has? That would be quite interesti...
by Valery
Wed Oct 10, 2018 2:18 pm
Forum: Solar Scope Modifications
Topic: PST Mods... but, why not a 40mm SolarMax Mod?
Replies: 13
Views: 236

Re: PST Mods... but, why not a 40mm SolarMax Mod?

Marty, If you want to get the most out the equipment you got and get the most cost effective high res solar telescope, then better use tested solutions which showed that they really work as needed. Forget all these SM35, SM40 etc. a) Full size DERF + C8 + standard Quark Chromosphere + Camera (depend...
by Valery
Mon Oct 08, 2018 2:07 am
Forum: This is SolarChat !!
Topic: Sharpening high resolution CaK images
Replies: 25
Views: 585

Re: Sharpening high resolution CaK images

this is probably the end of the solar season for me. Same for me. However I hope for some warm higher pressure area will "visit" us this season. But... as you said earlier, you have a lot of material (taken last summer) to process. Lets do the processing of these materials and show to our collegues...
by Valery
Sun Oct 07, 2018 7:33 am
Forum: This is SolarChat !!
Topic: Sharpening high resolution CaK images
Replies: 25
Views: 585

Re: Sharpening high resolution CaK images

This is one I tried to answer in the book I am publishing at the end of the month. http://www.astronomiesolaire.com/ Indeed, I have a paragraph on "reverse granulation", and an extensive discussion on artifacts and the limit between processing and over-processing. So here is a sneak preview ;-) Rev...
by Valery
Thu Oct 04, 2018 4:15 am
Forum: Solar Scope Modifications
Topic: Pst Cak filter secret -
Replies: 19
Views: 448

Re: Pst Cak filter secret - Vengeance against chroma

C'est la vie, Apollo. For once I agree with you entirely Valery. It is clear as day that Everyone is just out to take advantage of each other in this field. I do have some choice words for one person in particular, but I will keep them to myself. Karma is a nasty beast , and they wont able to avoid...
by Valery
Wed Oct 03, 2018 9:07 pm
Forum: Solar Scope Modifications
Topic: Pst Cak filter secret -
Replies: 19
Views: 448

Re: Pst Cak filter secret - Vengeance against chroma

C'est la vie, Apollo.
by Valery
Wed Oct 03, 2018 8:36 pm
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 200
Views: 6010

Re: Narrowest 393.37 ever by Apollo Lasky

The price for a single cavity is $2250 and for a two cavity filter I'd expect at least $4000. If a two cavity filter will be a stack of two single cavity filters (each of 1A FWHM) then it should have FWHM about 0,75A - 0,8A with steep sides and well supressed skirt. Still not enough to see dark fila...
by Valery
Wed Oct 03, 2018 6:14 pm
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 200
Views: 6010

Re: Narrowest 393.37 ever by Apollo Lasky

I don't know why there is a discrepancy, all I know is that this is the data Dick Stewart sent me. My filter also appears to need more than 1.5 degrees of tilt, but I have yet to calculate it from what I can measure in the Skybender - going to have to brush up on my trigonometry skills ;-) Dick did...
by Valery
Wed Oct 03, 2018 7:15 am
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 200
Views: 6010

Re: Narrowest 393.37 ever by Apollo Lasky

TheSkyBurner wrote:
Wed Oct 03, 2018 5:33 am


This will be the only time I ask for help, because I need funds for a future development.
Do you mean spinal surgery/probe equipment development you recently announced? I belive this is much more
important than playing with sun imaging.


Valery
by Valery
Tue Oct 02, 2018 8:15 am
Forum: This is SolarChat !!
Topic: Sharpening high resolution CaK images
Replies: 25
Views: 585

Re: Sharpening high resolution CaK images

1. user uploaded images online are a false impression of what is "real" and 99% of all astronomy photos are not "real"; They are an artist ability based on software processed enhancement. 1. Do not be fooled by user data processing. I'd say: 1. 100% of raw astroimages are not real. A correct image ...
by Valery
Tue Oct 02, 2018 1:44 am
Forum: This is SolarChat !!
Topic: Impact of telescope height on the seeing
Replies: 17
Views: 460

Re: Impact of telescope height on the seeing

Montana wrote:
Mon Oct 01, 2018 10:54 am
Very interesting! however I am barely tall enough to mount my telescope at 1m :lol:

Alexandra
We all know well about british grass lawns!

My SCT scopes are about 1,2 - 1,6m elevation (entrance aperture) above a grassy lawn level. :)
by Valery
Tue Oct 02, 2018 12:56 am
Forum: This is SolarChat !!
Topic: Sharpening high resolution CaK images
Replies: 25
Views: 585

Re: Sharpening high resolution CaK images

DOT sun images are lucky imaging results. I can say more: the lucky imaging technique was basically developed by the DOT team. This is the reason why all the lucky imaging amateur softwares (Registaks, AVIStack and AutoStekkert) are from the Netherland, where the DOT team is based. This technique lu...