Search found 380 matches

by krakatoa1883
Thu Mar 21, 2019 11:46 am
Forum: This is SolarChat !!
Topic: AR2735 AR2736 2019 3 20
Replies: 6
Views: 62

Re: AR2735 AR2736 2019 3 20

Great set of images, Pepe, spectacular flaring!
by krakatoa1883
Mon Mar 18, 2019 12:30 pm
Forum: Solar Scope Modifications
Topic: 150 mm Solar Newton
Replies: 27
Views: 382

Re: 150 mm Solar Newton

Anyone who has tested an uncoated mirror on the Moon will confirm there is still a great deal of light reflected. One should be very careful about filtering such telescopes since apertures can easily exceed most amateur's refractors. indeed this is the main advantage of solar reflectors, they makes...
by krakatoa1883
Sun Mar 17, 2019 9:38 pm
Forum: Solar Scope Modifications
Topic: 150 mm Solar Newton
Replies: 27
Views: 382

Re: 150 mm Solar Newton

Does it "warm up" above ambient and then need forced cooling? THis may be the problem rather than passing air currents through the OTA. it depends on the mirror material as explained in the link to Viladrich's newtonian. I never found my mirror hotter than ambient temperature, at least by touching ...
by krakatoa1883
Sun Mar 17, 2019 9:33 am
Forum: Solar Scope Modifications
Topic: 150 mm Solar Newton
Replies: 27
Views: 382

Re: 150 mm Solar Newton

I thought it would be better to work with a secondary as small as possible, if not for the contrast, then to minimise the aperture loss. in general the smaller the secondary obstruction the better the performance for high resolution work. However sunspot umbrae and penumbrae represent black-grey de...
by krakatoa1883
Sat Mar 16, 2019 5:24 pm
Forum: Solar Scope Modifications
Topic: 150 mm Solar Newton
Replies: 27
Views: 382

Re: 150 mm Solar Newton

A solar newtonian is a very useful addition to a solar setup. I made my own and I am very happy, It is useful for both WL, K-line and Ca-H without the need of expensive ERFs. Diameters larger than 5 or 6 inch require an open tube and a careful design to avoid internal turbulence. It is safe also for...
by krakatoa1883
Tue Mar 12, 2019 10:17 am
Forum: This is SolarChat !!
Topic: March 9th - Ha Images
Replies: 12
Views: 171

Re: March 9th - Ha Images

Fine images, Brian, and a very good setup.
by krakatoa1883
Tue Mar 12, 2019 10:16 am
Forum: This is SolarChat !!
Topic: A prom from 03-08
Replies: 10
Views: 167

Re: A prom from 03-08

Very beautiful image, Maurits, why don't add some colour ?
by krakatoa1883
Sat Mar 02, 2019 10:35 am
Forum: Solar Scope Modifications
Topic: lunt 50 mod
Replies: 35
Views: 4745

Re: lunt 50 mod

I disassembled my own for cleaning, it is a cemented doublet (front is positive, rear is negative).
by krakatoa1883
Thu Feb 28, 2019 8:41 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Different Ca-K options, differences?
Replies: 72
Views: 7583

Re: Different Ca-K options, differences?

I have both a Lunt diagonal and the Quark H, they are different devices and I like both. The Quark calcium doesn't need a true telecentric beam to work however it performs best with a light cone slower than f/10, better around f/12 or f/15. It can be used down to f/7 but with a slight loss of contra...
by krakatoa1883
Sun Feb 24, 2019 8:12 pm
Forum: This is SolarChat !!
Topic: Weekend of fun in the sun with lots of new equipment
Replies: 16
Views: 334

Re: Weekend of fun in the sun with lots of new equipment

Great H-alfa images, Alexandra, really impressive, your Solarscope is a winner!
by krakatoa1883
Fri Feb 22, 2019 6:05 pm
Forum: This is SolarChat !!
Topic: Horse Protu 22 2 2019
Replies: 9
Views: 210

Re: Horse Protu 22 2 2019

Fantastic, Pepe, it's faint but well defined
by krakatoa1883
Fri Feb 22, 2019 6:00 pm
Forum: This is SolarChat !!
Topic: Filament 21 2 2019
Replies: 9
Views: 209

Re: Filament 21 2 2019

Nice image, Pepe, lot of details
by krakatoa1883
Wed Feb 20, 2019 8:23 pm
Forum: This is SolarChat !!
Topic: Februari 19
Replies: 12
Views: 278

Re: Februari 19

NIce limb image and prom. Agree with Astrophil about the fog, I noted it depends much on sky conditions and on how much the brightness has been increased to show the faintest parts of proms. In most cases I am able to correct the problem during processing, but not always, sometimes I have to accept ...
by krakatoa1883
Wed Feb 20, 2019 8:19 pm
Forum: This is SolarChat !!
Topic: February 18 Full Disk and 3 hour time lapse
Replies: 10
Views: 237

Re: February 18 Full Disk and 3 hour time lapse

Beautiful time lapse and disc, much detailed!
by krakatoa1883
Wed Feb 20, 2019 8:08 pm
Forum: This is SolarChat !!
Topic: Feb 16th Session
Replies: 13
Views: 246

Re: Feb 16th Session

Beautiful images, Brian, the CaK and the DS are particularly sharp.
by krakatoa1883
Mon Feb 18, 2019 5:01 pm
Forum: This is SolarChat !!
Topic: Solar images of February 16th
Replies: 10
Views: 235

Re: Solar images of February 16th

Thanks Eric, Alexandra and Maurits for you kind words :)
by krakatoa1883
Mon Feb 18, 2019 5:01 pm
Forum: This is SolarChat !!
Topic: anim prom Sun 13-02-2019
Replies: 20
Views: 341

Re: anim prom Sun 13-02-2019

Super animation, really spectacular!
by krakatoa1883
Sun Feb 17, 2019 3:49 pm
Forum: This is SolarChat !!
Topic: CaK, 16022019. SolarMonitor plus experiments
Replies: 17
Views: 354

Re: CaK, 16022019. SolarMonitor plus experiments

Really good images indeed. I am using the same scope for my calcium images, it is very well corrected for calcium imaging.
by krakatoa1883
Sun Feb 17, 2019 3:46 pm
Forum: This is SolarChat !!
Topic: Solar images of February 16th
Replies: 10
Views: 235

Re: Solar images of February 16th

Thanks to all you for your kind comments :D
by krakatoa1883
Sat Feb 16, 2019 8:51 pm
Forum: This is SolarChat !!
Topic: Sol from the 15th of February 2019 and its reflection.
Replies: 10
Views: 200

Re: Sol from the 15th of February 2019 and its reflection.

Great images, Eric, and beautiful Moon, very well processed!
by krakatoa1883
Sat Feb 16, 2019 5:27 pm
Forum: This is SolarChat !!
Topic: Solar images of February 16th
Replies: 10
Views: 235

Solar images of February 16th

Not much stuff to see today, however a nice filament and an associated plage area was visible in NE quadrant of the Sun. It looked prominent in my Quark Chromosphere so I decided to take an image through my Lunt-modified scope replacing the Lunt BF with the Quark. Between the PT module and the Quark...
by krakatoa1883
Mon Feb 11, 2019 10:50 am
Forum: This is SolarChat !!
Topic: Feb 10th - A Bit of an experiment!
Replies: 7
Views: 169

Re: Feb 10th - A Bit of an experiment!

That scope is no good for CaK at full aperture, it is too much aberrated at short wavelengths. Stop it down to 40-50 mm, you should note a marked improvement in definition.
by krakatoa1883
Fri Feb 08, 2019 5:14 pm
Forum: This is SolarChat !!
Topic: Big Bright Proms & Plage | 150mm HA | Feb 8th 2019
Replies: 16
Views: 340

Re: Big Bright Proms & Plage | 150mm HA | Feb 8th 2019

Nice images, Marty, detailed and well processed
by krakatoa1883
Tue Feb 05, 2019 12:12 pm
Forum: This is SolarChat !!
Topic: New Year, New Setup & the Blocking Filter Experiment - 3rd February
Replies: 22
Views: 594

Re: New Year, New Setup & the Blocking Filter Experiment - 3rd February

Great and even images, Mark, and interesting experience too. Thanks for sharing.
by krakatoa1883
Tue Feb 05, 2019 11:45 am
Forum: This is SolarChat !!
Topic: Full Disk 2/2/19
Replies: 8
Views: 257

Re: Full Disk 2/2/19

Wonderful sketch, very nice !