Search found 644 matches

by Bob Yoesle
Sat Dec 26, 2020 8:59 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Sony IMX253 mono cameras
Replies: 35
Views: 1112

Re: Sony IMX253 mono cameras

Thanks for that caution advisory Great Attractor :-) Well it looks like I have a pretty well regarded and very well-built laptop - the Dell Latitude E6420 circa 2011. I did a little internet searching and it appears it can be relatively easily upgraded with up to 8 GB of RAM, a (internal) 500 GB SSD...
by Bob Yoesle
Sat Dec 26, 2020 4:22 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Sony IMX253 mono cameras
Replies: 35
Views: 1112

Re: Sony IMX253 mono cameras

Thanks for the input gentlemen! In the meantime I've decided to pull the trigger. https://www.flir.com/products/grasshopper3-usb3/?model=GS3-U3-123S6M-C For $275.00 USD "as new barely used" (versus new OEM $3250.00) with a 30 day return option, it's seems a pretty good a deal, and if doesn't work ou...
by Bob Yoesle
Thu Dec 24, 2020 3:47 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Sony IMX253 mono cameras
Replies: 35
Views: 1112

Re: Sony IMX253 mono cameras

Thank you all for your input - and Merry Christmas! :D I'm still finding it a difficult decision. Some of these 2 year old cameras are showing up used for very reasonable prices - $200 - $300 USD versus their new cost of $2000 to $3000 USD. I'm mostly interested in this particular sensor because the...
by Bob Yoesle
Wed Dec 23, 2020 5:01 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Sony IMX253 mono cameras
Replies: 35
Views: 1112

Sony IMX253 mono cameras

I'm pretty behind the times when it comes to the newer sensors and the latest laptops. Has anyone used one of these for solar? It's the CMOS Pregius IMX253 1.i inch 12 MP with 3.45 um pixels? https://www.phase1vision.com/userfiles/product_files/imx253_255llr_lqr_flyer.pdf Thinking of going to this s...
by Bob Yoesle
Tue Nov 24, 2020 5:37 pm
Forum: Solar Scope Modifications
Topic: G band instead of Ca-k filter
Replies: 48
Views: 1579

Re: G band instead of Ca-k filter

Resolution is wavelength dependent. So a shorter wavelength with the same aperture has the potential to have higher resolution if the optics and seeing conditions allow. For imaging of course you would need to match pixel size to the higher resolution to realize the benefit. For example, the differe...
by Bob Yoesle
Tue Nov 24, 2020 4:11 am
Forum: Solar Scope Modifications
Topic: G band instead of Ca-k filter
Replies: 48
Views: 1579

Re: G band instead of Ca-k filter

An f10 achromatic refractor is your best bet for significantly better spherochromatic aberration at 430 nm: https://www.telescope-optics.net/achromats.htm A shorter f ratio APO or semi-APO (except Tak TAO 130/150 ;-) will generally not perform as well: https://www.telescope-optics.net/semiapo_and_ap...
by Bob Yoesle
Mon Nov 23, 2020 2:54 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Advice requested on Quantum filter purchase
Replies: 56
Views: 2487

Re: Advice requested on Quantum filter purchase

Hi Alan, Looks to me like you have two issues: 1. A DERF keeps the filter cooler from the start. Your first image is closest to on band where the filter was nearer to ambient temp. As the filter heats up more, it is shifted further into the red wing and goes off band. The second set of images withou...
by Bob Yoesle
Thu Nov 19, 2020 2:02 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Coronagraph
Replies: 9
Views: 464

Re: Coronagraph

Since you're talking H alpha filters, it seems you're talking about a solar prominence telescope (e.g. the chromosphere), not a coronagraph. There's a huge difference. https://en.wikipedia.org/wiki/Coronagraph You may want to review this couple of threads on Cloudy Nights: https://www.cloudynights.c...
by Bob Yoesle
Mon Nov 09, 2020 3:38 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Advice requested on Quantum filter purchase
Replies: 56
Views: 2487

Re: Advice requested on Quantum filter purchase

I've emailed DayStar to request a test report for my replacement PE etalon. This whole topic brings up an important issue for consumer narrow band solar filters. At least DayStar produces a report for some of their filters. I note however in both the reports reported above there is no measurement fo...
by Bob Yoesle
Sun Nov 08, 2020 6:07 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Advice requested on Quantum filter purchase
Replies: 56
Views: 2487

Re: Advice requested on Quantum filter purchase

Thanks for that information Rainer. I'll give DayStar a call and see if I can get the test report that is generated for all PE grade filters:

http://www.daystarfilters.com/QuantumPE.shtml
by Bob Yoesle
Sat Nov 07, 2020 2:25 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Lunt VS Coronado BF
Replies: 7
Views: 484

Re: Lunt VS Coronado BF

I have a 60mm external Etalon (Coronado....US made and pre Lunt_) ...the ERF on the BF had rusted so called Lunt. Just a couple of minor corrections / clarifications: Typically a US made Coronado filter is not "pre Lunt," it would be pre-Meade. There was a short period of time (~ 1 year) after Mead...
by Bob Yoesle
Sat Nov 07, 2020 1:50 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Advice requested on Quantum filter purchase
Replies: 56
Views: 2487

Re: Advice requested on Quantum filter purchase

Update from DayStar - my filter was returned. A followup email from DayStar stated the etalon was replaced - which likely accounts for the long turnaround period. I'm waiting for some decent weather (could be weeks now in the Pacific Northwest) to determine how well it performs. Fingers (and toes ;-...
by Bob Yoesle
Wed Oct 28, 2020 1:29 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Advice requested on Quantum filter purchase
Replies: 56
Views: 2487

Re: Advice requested on Quantum filter purchase

Recently a friend ordered a double stack filter set from Solarscope and was disappointed that they didn’t match up to his (excellent) Lunt DS. His money was returned immediately - no quibbles. My experience with the SolarScope DSF100 filters was that they were quite temperature sensitive, and could...
by Bob Yoesle
Fri Oct 23, 2020 3:23 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Advice requested on Quantum filter purchase
Replies: 56
Views: 2487

Re: Advice requested on Quantum filter purchase

Hi Alexandra, Yikes! That's a horror story worthy of Halloween. The Quantum SE and PE filters do however come with an adhesive label with a serial number. Of course it could be removed and/or replaced... but I just hope they are really busy and I will eventually get a fully functional filter back to...
by Bob Yoesle
Thu Oct 22, 2020 2:45 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Advice requested on Quantum filter purchase
Replies: 56
Views: 2487

Re: Advice requested on Quantum filter purchase

I do not want to say anything bad about Daystar but I bought some not long ago, April 2018, a QUARK and a QUANTUM PE 0.4Angström and both were blind. It took me over a Year to solve this problem with Daystar. In this regard the customer service was horrible. I paid that time US $ 13,700.00 for both...
by Bob Yoesle
Sat Sep 19, 2020 12:39 am
Forum: This is SolarChat !!
Topic: Seattle Sun- Smoke filtered sunlight
Replies: 6
Views: 251

Re: Seattle Sun- Smoke filtered sunlight

Smoke filtering.jpg About seven days ago in eastern Washington State. Visibility about 800 meters. Then it got worse, for a few days visibility less than 400 meters, and no sun at all. We've had to wear an N95 mask for the smoke for the limited times we went outside (let alone Covid 19 exposure pre...
by Bob Yoesle
Wed Sep 16, 2020 7:26 am
Forum: Solar Scope Modifications
Topic: Replacing Lunt CaK BF with something better
Replies: 17
Views: 827

Re: Replacing Lunt CaK BF with something better

Hi Ken,

That's similar to what I have. Most all of my imaging to date has been done with a PGR (FLIR) Chameleon with ICX445 CCD @ 3.75 um pixels.

With the ED100/900 this gives me 0.86 arcsec/pixel. When seeing allows, the TeleVue 2x Big Barlow yields ~ 0.43 arcsec/pixel.
by Bob Yoesle
Tue Sep 15, 2020 4:24 pm
Forum: Solar Scope Modifications
Topic: Replacing Lunt CaK BF with something better
Replies: 17
Views: 827

Re: Replacing Lunt CaK BF with something better

Like Mark and others, I find the CaK filter gives better (repeatable) results when used at f10 (or greater)... True, however my scope is well corrected in CaK even at full aperture so I would prefer to maintain resolution if I can. However I'll do some tests to see what gives better results, full a...
by Bob Yoesle
Sat Sep 12, 2020 6:13 pm
Forum: This is SolarChat !!
Topic: Older Halpha diagonal tuner
Replies: 3
Views: 166

Re: Older Halpha diagonal tuner

The tilt-tuned blocking filters were from the Isle of Man Coronado days. The model you're referring to is the Prom 15 T:

Prom 15T side.jpg
Prom 15T side.jpg (129.96 KiB) Viewed 149 times
Prom 15T back.jpg
Prom 15T back.jpg (90.18 KiB) Viewed 149 times

The was also the tilting BF30:

IOM BF30.jpg
IOM BF30.jpg (197.64 KiB) Viewed 149 times
by Bob Yoesle
Fri Sep 11, 2020 7:38 pm
Forum: This is SolarChat !!
Topic: NASA, NOAA to Discuss Solar Cycle Prediction During Media Teleconference
Replies: 4
Views: 224

Re: NASA, NOAA to Discuss Solar Cycle Prediction During Media Teleconference

Thanks for the information Frank. I note that Dr. Upton is on the panel, and she collaborates with Dr. Hathaway who recently retired from NASA. Their predictions can be found here:

http://solarcyclescience.com/forecasts.html
by Bob Yoesle
Thu Sep 10, 2020 7:25 pm
Forum: This is SolarChat !!
Topic: How much pressure is in a pressure tuned etalon? And more
Replies: 16
Views: 519

Re: How much pressure is in a pressure tuned etalon? And more

You could also make a second fine pressure tuner along the same principles but with a much smaller internal bore and a long throw (thread) to make it easy to adjust, use the original tuner to get up to pressure then the second one for getting perfectly on band. Ralston ( https://www.ralstoninst.com...
by Bob Yoesle
Thu Sep 10, 2020 5:30 am
Forum: This is SolarChat !!
Topic: How much pressure is in a pressure tuned etalon? And more
Replies: 16
Views: 519

Re: How much pressure is in a pressure tuned etalon? And more

The LUNT PCUSB Controller: https://luntsolarsystems.com/shop/accessories/lunt-pc-usb-pressure-tuner-controller/ This diagram from LUNT shows what at typical air-pressure tuned etalon does: Etalon pressure tuning.jpg Note that at sea level with no additional pressure the filter is off-band blue, and ...
by Bob Yoesle
Wed Aug 19, 2020 12:30 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: L'observatoire du Soleil. High Resolution Solar Observer
Replies: 7
Views: 902

Re: L'observatoire du Soleil. High Resolution Solar Observer

Hmmm... What sounds good in theory often does not work out well in reality. This is especially true of daytime solar observation versus nighttime observations. I generally don't have enough good daytime seeing to effectively use over ~ 150 x, and usually half that is my sweet spot. The other item is...
by Bob Yoesle
Mon Aug 17, 2020 8:37 pm
Forum: This is SolarChat !!
Topic: CaK and Ha with a T250
Replies: 12
Views: 486

Re: CaK and Ha with a T250

Lovely, especially the CaKs.
by Bob Yoesle
Mon Aug 17, 2020 8:32 pm
Forum: This is SolarChat !!
Topic: My first solar scope (150 F/8 unaluminized reflector)
Replies: 29
Views: 1054

Re: My first solar scope (150 F/8 unaluminized reflector)

Wow - that's really a nice history pedro! And speaking of toilet rolls... Your post reminded me of my first home made telescope - also a 6 inch f/8 cardboard tube Newt on a pipe mount. I ground and figured the mirror in the 7th grade (top left, next to my 1962 Christmas present - a 60 mm Unitron ;-)...