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SPECIFIC FILTER BRAND TESTING |
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Title |
Description |
Date |
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"Omega Optical Improved NPB DGM Filter", 4.1Mb |
Omega has produced the LP filter I have been searching
for: two very narrow high transmission band passes around
Hbeta/O-III and Halpha. This report summarizes my
testing of the filter both visually and with an astro-video
camera. |
Jan 2015 |
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"Optolong Preliminary Filter Test Report", 0.8Mb |
Summary of some initial testing that I did on a batch of
sample filters from Optolong (Yulong Optics Co., Ltd). |
Aug 2015 |
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"Optolong L-eXtreme Filter Comparison", 5.9Mb |
Summary of my testing where I compare a range of
Optolong brand light pollution filters, including the new L-eXtreme. |
Aug 2020 |
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"Radian Triad & Triad Ultra Performance vs F-ratio",
3.7Mb |
Test report summarizing my more detailed investigation
into how the performance of the Radian Triad and Triad Ultra
filters are affected by optics f-ratio. |
Oct 2020 |
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"IDAS Filter Comparison Testing", 10.0Mb |
Test report summarizing my evaluation of all
models of filter sold by IDAS. Report includes bench
testing (spectrometer) and field testing (imaging). |
Nov 2021 |
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"Optolong L-eXtreme F2 Testing", 25.5Mb |
Test report summarizing my evaluation of the
prototype Optolong L-eXtreme F2 filter. Spectrum
measurements and images are used to compare the filter's
performance to existing Optolong filter models. |
Dec 2021 |
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"Antlia ALP-T Filter Comparison Test", 16.0Mb |
Test report summarizing my testing of the new Antlia ALP-T filter.
Spectrum measurements and images are used to compare the ALP-T to
four existing multi-narrowband filters: IDAS NB-1, IDAS NBZ,
Optolong L-eXtreme, & Radian Triad Ultra. Rev. 1 w/
updated spectrum data using upgraded spectrometer. |
Jun 2022 |
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"Narrowband Halpha Comparison Test", 9.4Mb |
A back-to-back comparison of performance between Halpha filters with
different FWHM, from 40nm down to the 3nm wide Optolong and Chroma
brand filters. |
Aug 2022 |
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"SHO Filter Comparison Test", 5.1Mb |
Comparing Sulfur-Oxygen-Hydrogen narrowband filter sets against each
other and comparing performance, one set with ~7nm wide pass bands (IDAS)
and the other with 3nm wide pass bands (Optolong). |
Aug 2022 |
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"3nm Multi-Narrowband Filter Comparison", 28.3Mb |
A comparison test between the Optolong L-uLtimate and Askar Colour
Magic 3nm Duo-Narrowband filters. Filters are compared based
on their measured spectrums and imaging results. |
Oct 2022 |
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"Testing
Multi-Object Type Filters", 26.2Mb |
A comparison test between two new filters: the Antlia Triband
RGB Ultra, and the IDAS Galaxy & Nebula Booster (GNB). I
compare the performance of these two filters to that of other
pre-existing filters, both by spectrometer measurement and imaging. |
May 2023 |
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"Testing
the Player One Pro Dual-Band Filter", 6.1Mb |
Player One's Pro Dual-Band is the latest offer in the 3nm
multi-narrowband filter category. I put the filter up against
the Optolong L-uLtimate and Askar Duo-Band Narrowband. |
Oct 2023 |
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"Testing
the Optolong L-Quad Enhance Filter", 7.6Mb |
Optolong's new L-Quad Enhance Filter (L-QEF) is compared to other
existing filters in the multi-broadband category. Performance
is compared in terms of predictions based on the measured filter
spectra, as well as comparison images of various deep-sky target
types. |
Nov 2023 |
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"Testing
the Antlia Quadband Anti-Light Pollution Filter", 26.9Mb |
Antlia's new Quadband Anti-Light Pollution (Quad ALP) filter is
compared to other similar filters with the objective of finding
which filter is the best general purpose filter, i.e. what filter
delivers good performance on all deep-sky object types. |
Nov 2023 |
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GENERAL FILTER TESTING |
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"Band
Pass Filters For Visual & Video Astronomy - Part 1" ,
3.9Mb
|
A redo of the Deep-Sky filter portion of my original
filter research web-paper, this time including the Mallincam
CCD as well as the human eye. Added several new
filters, including Halpha filters. Contains test
results for a large number of LP filters. Part 1 is
the body of the report. |
Apr 2012 |
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"Band
Pass Filters For Visual & Video Astronomy - Part 2" ,
4.7Mb |
Part 2 contains the appendices that accompanies the
report. The appendices are mostly the images that were
collected from my Mallincam during testing with a large
assortment of different LP filters. The target was M42
Orion Nebula. |
Apr 2012 |
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"LP Filters Under Dark Skies" 2.2Mb |
A presentation of theory and observations surrounding
what happens if you use light pollution filters under dark
skies. |
May 2013 |
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"LP Filters & Monochrome Cameras", 11.6Mb |
Screen captures made during some testing using a monochrome
astrovideo camera and a range of LP filters. |
Sep 2014 |
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"Polarizing Filters & Nebulae", 0.9Mb |
A short test to examine the impact of using a linear
polarizing filter on an emission nebula from a light
polluted location. |
Jan 2015 |
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"Multi Narrowband Filters", 7.1Mb |
A detailed series of tests comparing the various brands
of multi narrowband filters that are available today. |
Feb 2020 |
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"Narrowband Filters & Fast Optics", 3.3Mb |
Using a combination of measured filter band
shift data and theoretical narrowband filter spectra, I
predict the impact of using a narrow band pass filter on
fast optics. |
Nov 2020 |
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"Narrowband Filters & Fast Optics - Addendum", 10.1Mb |
An addendum to the main report containing
additional performance prediction plots for different
telescope types. |
Nov 2020 |
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"Understanding
Filter Induced Star Halos", 8.6Mb |
This report summarizes a series of different
tests I performed in an effort to better understand how and
why filters cause halos around bright stars. |
Nov 2022 |
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"How
Narrow is Too Narrow?", 12.3Mb |
Using H-alpha filters as a proxy for all
narrowband, this test report compares the impact of filter
band width (FWHM) on contrast increase and SNR. FWHM
values from >100 to 1nm are considered. The objective
was to determine if there is an optimum filter bandwidth. |
Jun 2023 |
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"Multi-Narrowband
Filters + Monochrome Cameras", 6.5Mb |
This article discusses the idea of using a
multi-narrowband filter, meant traditionally for use on a
one-shot colour camera, on a monochrome camera. |
Oct 2023 |
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FILTER TESTS INVOLVING IR PASS & IR CUT |
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"Managing IR in Video Astronomy - Part 1" , 2.2Mb |
A test report summarizing the visual impact of IR Cut
filters on the Mallincam. Testing was with an 80mm APO,
with the target being primarily the nebulous region around
Sadr (gamma Cygni). |
Aug 2011 |
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"Managing IR in Video Astronomy - Part 2" , 400Kb |
Part 2 of my testing of IR Cut filters on the Mallincam,
using my 8" SCT and the targets M27 and M57. |
Aug 2011 |
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"Managing IR in Video Astronomy - Part 3" , 1.8Mb |
Part 3 of my testing of IR Cut filters, focusing
specifically on the galaxy M31 using a 102mm TV camera lens.
Some time spent evaluating IR Pass filters. |
Sep 2011 |
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"Managing IR in Video Astronomy - Part 3 Addendum" ,
1.0Mb |
A re-look at the white balancing of my images from the
Part 3 test report. |
Sep 2011 |
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"Managing IR in Video Astronomy - Part
4" ,
3.3Mb |
Part 4 of my testing of IR Cut filters, focusing on the
galaxy M33 using an ED80 APO refractor reduced to f/3.
Spent more time evaluating IR Pass filters, as well as
comparing the results to my computational method for
evaluating filters. |
Feb 2012 |
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"Video Astronomy Using LP+IR Blocker" , 2.5Mb |
A re-look at using an LP filter with and without an IR
Cut filter added. In this test I also evaluate the custom IR
Cut filter I had made by Omega Optics. |
Jan 2012 |
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"Filters & Galaxies for EAA
Rev 1", 3.2Mb |
A fresh look at evaluating how a number of different LP
filters work to improve the contrast of galaxies when
observed with a camera under light polluted skies, both by
analysis and by test. Revised to include prediction
of filter performance under different levels of sky
darkness. |
May 2021 |
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FOCAL REDUCER TESTING |
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"Playing With Focal Ratio 1" , 3.9Mb |
An extensive test using my ED80 APO refractor, visually
comparing the effect of different focal ratios and different
integration times. |
Jan 2012 |
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"Playing With Focal Ratio 2" , 1.1Mb |
A follow-on test that repeats my focal ratio work using
my 8" LX-10 SCT. The test visually compares the effect
of different focal ratios and different integration times. |
Jan 2012 |
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"Detailed Look At Focal Reducers", 2.2Mb |
Summary of a large number of tests using various focal
reducers, varying spacings to see what kinds of reduction
factors and changes in focus position result. |
Sep 2013 |
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"Medium Sized Sensor FR Testing", 1.8Mb |
Summary of testing a variety of FR configurations using
a camera with sensor 13.4mm diagonal size. |
May 2016 |
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"Medium Sized Sensor FR Testing - Follow-up", 0.7Mb |
A followup to the test report from earlier in May,
examining the Meade f/6.3 SCT focal reducer in more detail. |
May 2016 |
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OTHER HARDWARE TESTING |
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"Mallincam
Xtreme Warm Pixel Test" , 9kb |
A quick test of my Mallincam Xtreme with lens cap on, to
determine how many warm pixels are visible at different AGC
and INT times. |
Mar 2012 |
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"Video
Ritchey-Chretien 8" , 10.6Mb |
A summary of my extensive back-to-back tests of the VRC8
versus my 8" LX10. |
Apr 2012 |
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"Video
Ritchey-Chretien 8 - Appendix A" , 606kb |
An appendix to the main test report that discusses the
different optical coating systems available today, including
how they impact the observed performance of the VRC versus
an SCT. |
May 2012 |
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"ICX825 Based Astro-Video Camera Comparison", 1.3Mb &
"825 Camera Comparison Table" 91Kb |
A three-way comparison test between the ICX825 based
Atik Infinity-C, Starlight Xpress Ultrastar-C, and Mallincam
Starvision-C |
Oct 2016 |
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"CCD vs CMOS for Video Astronomy", 2.0Mb |
Summary of a side-by-side comparison test between a CCD
based camera (Lodestar X2C) and a CMOS based camera
(ASI290MM) |
Nov 2017 |
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"ASI294MC Pro vs DS10C-TEC Camera Comparison - Part 1 -
Physical", 1.9Mb |
A thorough comparison of two high performance cameras
that use the Sony IMX294 sensor. This first part
reviews the overall physical properties of the cameras. |
Nov 2018 |
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"ASI294MC Pro vs DS10C-TEC Camera Comparison - Part 2 - Dark
Frames", 2.2Mb |
A continuation of my comparison testing, this time
looking at dark frames generated by the cameras for a range
of camera settings. |
Dec 2018 |
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"ASI294MC Pro vs DS10C-TEC Camera Comparison - Part 3 -
Signal to Noise Ratio & TTOI", 2.8Mb |
Part 3 of my comparison testing, this time looking at
the SNR produced by each camera for a range of gains and
exposure times. I also present a new parameter for
comparing camera performance: Time To Observable Image
(TTOI) |
Dec 2018 |
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"ASI294MC Pro vs DS10C-TEC Camera Comparison - Part 4 -
Physical", 1.7Mb |
The 4th and final part of my comparison testing.
This final report compares the cameras in terms of fixed
pattern noise, and resistance to fogging. |
Jan 2019 |
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"Measuring My Backyard LP Spectrum", 2.5Mb |
A brief review of the sources of light
pollution, my attempt to model it, and a summary of
validation measurement I made of my backyard LP spectrum. |
Nov 2021 |
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"Solar Camera Comparison Test", 2.8Mb |
A back-to-back comparison test between
monochrome cameras with 4 different sensors: IMX290,
IMX183, IMX226, and IMX432. The Sun was imaged in
multiple wavebands using these four sensors:
Calcium-K, Solar Continuum, Helium-D3, and Hydrogen-alpha. |
Aug 2022 |
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"Spectrometer Configuration Impact on Spectrum Measurement",
2.4Mb |
A report documenting my investigation of how
a spectrometer's wavelength resolution affects its ability
to accurately characterise the spectrum from a narrowband
filter. Also documented is the work I did to upgrade
my spectrometer to deliver a better resolution. |
Aug 2022 |
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"Choosing
a Solar Imaging Camera", 2.4Mb |
An article I wrote presenting a basis for
choosing the best suited camera for solar imaging depending
on the particulars of your scope and waveband. |
Jun 2023 |
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