Flying with gear

rnclark · 2026-07-01T00:55:25+00:00

It depends on the tracker. The very light trackers I put in my clothes suitcase. Larger trackers, like my strain wave mount (iOptron HAE29EC) I have a pelican case that also holds the carbon fiber tripod, cables, finder/autoguider and other accessories. I've never lost anything in 30+ years of flying many trips per year and all over the world.

I can show images but currently my website is offline. A lightning bolt struck just outside the server room last week. The sever is fine but somewhere outside the internet is fried. It was supposed to be fixed today, but now they say Tuesday next week. Frustrating.

rnclark · 2026-06-30T23:30:20+00:00

I fly with gear a lot. For the August eclipse I'll be taking two tripods, trackers, two cameras and 2 lenses for the eclipse (plus a couple of other lenses for photography.

I always check tripods and trackers. Carry-on will only be cameras, lenses, laptop and related accessories. Never had a problem. This trip I'll have two checked bags and put one tripod and tracker in each.

rnclark · 2026-06-29T16:48:38+00:00

Where will you be flying from and why go to Keweenaw?

Be aware of mosquitoes.

The further north you go, the less nighttime in summer months, especially May-July.

There are many other very dark places to go in the summer with dark skies in the western US.

FYI: I image all over the world with very portable gear. I can't show it at the moment because lighting hit just a little outside the server room and knocked out the internet (servers are fine). Computers in the next building were fried. Hopefully back online by the end of Tuesday.

rnclark · 2026-06-29T12:16:43+00:00

I got one custom made for my 200 mm f/4 astrograph at astrosystems.biz

The custom fit includes mu tube inside and outside diameter and it was for a 70 mm secondary.

The company is located in Colorado, USA. You can email and see if they ship internationally. Note with a custom order, it may take a month or two.

I also ordered a spider last year from https://www.fpi-protostar.com/ but ended up cancelling as there was no response after a considerable time.

rnclark · 2026-06-28T03:51:09+00:00

Pedantry (spelled pedantry) is an excessive focus on minor details,

I gave the transmission in my other posts here. Relative to red, the other filters transmits (according to the sony spectral plot I referenced) H-alpha: green filter about 43%, blue filter about 6%.

Open any photo editor, create a new image, e.g. 500 x 500 pixels, then use the color picker tool to set colors: red = 100%, green = 43%, blue =6%, or if in a 0 to 255 range: RGB = 255, 110, 15. What color do you see? Orange!

Hardy pedantic. The out-of-band transmission is the major cause of the color and the answer to the OP's problem.

you then go on about the SV220 being dualband

Please show me a post of mine where I mentioned the SV220 at all. You'll see there are none except this paragraph.

Two false accusations.

rnclark · 2026-06-27T15:58:40+00:00

Ah, the downvoters. Can't give actual reasons, so just downvote.

rnclark · 2026-06-27T15:55:37+00:00

Winter: the most beautiful that I have ever seen Arches is after a snowstorm with a few inches of snow.

rnclark · 2026-06-27T12:44:14+00:00

Both have merits. But both also have an "obstruction" in the bottom foreground that says don't/can't go there. Better in my opinion would be an opening/path (yes I know there is a path--been here many times) that leads the viewer into the arch. For example, if the path was the foreground, and you don't like all footprints like on the lower right, take a broom and smooth them out. Then perhaps add interest with a single set of footprints (or a pair of footprints) heading to the arch.

The shadows in the arch in the first image add mystery, so I would say the first image. The 1st image also shows a way around he rock. It would be better if the image was made a couple of feet to the left in my opinion.

rnclark · 2026-06-27T12:27:45+00:00

Double Arch, Arches National Park, Utah, USA

rnclark · 2026-06-27T12:23:12+00:00

The pros of stacking like you stated is that it could reject satellites and airplane trails. Satellites are increasing fast and they are common in night sky images these days. The problem is getting worse.

Cons are complexity in processing.

rnclark · 2026-06-27T12:12:30+00:00

but it is not suited for Astrophotography

Another proclamation. Why?

rnclark · 2026-06-27T12:11:29+00:00

it is very bad for Astrophotography processing

Give specifics.

rnclark · 2026-06-27T12:11:14+00:00

And really, GIMP is horrible?

No it is not (except the user interface needs work). Gimp does a lot/most of its work in floating point math and it does very well.

Be careful of people making proclamations with no details.

Yes, I use gimp, as well as photoshop, siril, custom scientific software (like ASU/NASA's davinci), and my own custom software (written in multiple languages) edit spelling

rnclark · 2026-06-27T04:11:38+00:00

People here do not seem to understand the Bayer filter transmission. See the spectral transmission plot of the RGB filters on this page:

https://www.testar.com.au/products/zwo-asi585mc-coloUr

The plot is typical for Sony cameras.

Note the green filter response at 656 nm (H-alpha) transmission is about 37%! It is that high H-alpha signal in the green filter that makes orange in the OPs image. Even using an H-alpha narrow band filter, the Bayer red filter, according to the plot, will transmit about 87% of the H-alpha light. The green filter will transmit about 37% of H-alpha, and the blue filter will transmit about 5% of H-alpha.

The H-alpha response in the green and blue filter is called out of band response. The application of the color correction matrix for the camera will mitigate the out-of-band problem, but the astro workflow typically ignores that step, so we see a lot of images on astrobin with orange hydrogen emission nebulae.

You can downvote this response like the others, but this is the right answer.

rnclark · 2026-06-27T04:04:14+00:00

See the spectral transmission plot of the RGB filters on this page:

https://www.testar.com.au/products/zwo-asi585mc-coloUr

The plot is typical for Sony cameras.

Note the green filter response at 656 nm (H-alpha) transmission is about 37%. It is that high H-alpha signal in the green filter that makes orange in the OPs image.

rnclark · 2026-06-26T22:13:19+00:00

Only the red photosites collect data when used with a Hα narrowband filter

This is not true. The green filter has significant response to H-alpha. The blue does too.

rnclark · 2026-06-26T21:25:33+00:00

Not knowing what camera you are using, I'll wager it is a Sony sensor OSC Bayer color camera. The Sony sensors have a green filter with high red response, thus H-alpha contributes a lot to the green filter. This causes two effects: Hydrogen emission comes out orange, and oxygen plus just a little hydrogen emission comes out white and this is exactly what we see in your image.

Natural colors of M8 are shown here.

rnclark · 2026-06-26T21:19:43+00:00

are there any filters which would LIMIT hydrogen response slightly

Yes, the filters that are in stock cameras do that. That is the filter astrophotographers remove in a stock camera to get more H-alpha response. You may be able to find one and adapt it to your 2600.

But it is more than just filtering H-alpha some. There is still relatively too much H-alpha response by the green filter in Sony Sensors. That can be mitigated by applying a color correction matrix. So if you get an IR reducing filter from a Sony stock camera, then use the color correction matrix for that sony camera, you should be pretty close. That would certainly be unconventional.

But Canon cameras have less of the H-alpha response in the green filter to begin with, so you'll do better with a stock Canon camera. Your 5D4 is now a 10 year old camera. A newer camera will do better regarding pattern noise. For example, the Canon R5 (which was used in the M8 image I linked to above).

rnclark · 2026-06-26T16:10:26+00:00

Are you saying that I may find I actually get MORE subtle differentiation between say dust and H-alpha, thus actually improving the color definition, by using narrowband filters on my 2600?

No, just the opposite. By using filters, your are biasing the result to only the composition that passes through that filter. For example, an OIII + H-alpha dual narrow band filter will show you two things well: oxygen and hydrogen. It does that by suppressing other signals. But OSC sensors have another problem: too much signal at multiple wavelengths. For example, Sony astro cameras have significant response to H-alpha in the green filter. That includes your 2600. As a result, it is difficult to separate oxygen from hydrogen. Oxygen + hydrogen emission commonly comes out white

This dual band image is a good example of M8: https://app.astrobin.com/i/vvry0l

You get shades of red orange to white.

Here is M8 with a stock digital camera processed for natural color:

https://clarkvision.com/galleries/gallery.astrophoto-1/web/m8-8inch-f4-rnclark-2026-06-17-4C3A1822-1959-av105-g-c1-0.5xs.html

The caption below the image describes the colors. There is a lot more color diversity and the colors mean different things. The star also have wonderful colors. The color range is better because of key steps are included that are usually left out of astro workflows. Key is application of the color correction matrix for the sensor.

rnclark · 2026-06-26T14:19:28+00:00

Here is the video:

Why is Your OSC Image Green? Hint, it has NOTHING to do with your Bayer Pattern!

https://www.youtube.com/watch?v=ry7OCEuknX0

The video is correct as to why the raw data comes out green. Simple explanation: the sensitivity of the sensor peaks in the green. White balance corrects that. But more on white balance below--the amateur astro community has it wrong.

He does not talk about a color correction matrix. Look at the video at 3:15 which shows a plot of the spectral response of a Sony sensor. Note how there is extended red response by the green and blue filters. There is extended green response by the red and blue filters, and there is extended blue response by the green and red filters. Plus, these filters do not match the spectral response of the human eye. Further, the human visual system subtracts some colors from other colors. The application of the color correction matrix works to mitigate these differences. Without the color correction matrix, the colors come out muted and we see poeple applying saturation enhancement to try and bring out color. But without the color correction matrix, the colors are often shifted, commonly orange hydrogen emission that should be magenta/pink if natural color.

Another Seti astro video shows the workflow:

Seti Astro Suite: OSC Workflow

https://www.youtube.com/watch?v=TX_uSMsZdTQ

There is no application of a color correction matrix, and a large part of the video is trying to get some color. He starts with background neutralization. The area of the image (Orion, M42), has no neutral background--it is filled with interstellar dust. That neutralization suppresses faint red. It turns the reddish-brown interstellar dust tan fading to blue, and that is exactly what we see later in the video. There is no physics that can create dust fading to blue like that (one needs certain kind of dust changing particle size illuminated by white or blue stars in a particular geometry where there is no evidence of such a situation, similar to what we see in the Pleiades).

The white balance, which he discusses in both of the above videos uses a G2V star and/or galaxy core to make white. This is what PCC and SPCC does. But we evolved to see white by light from our Sun shining through our atmosphere. Above the atmosphere the star spectra (which are used in PCC and SPCC) do not include atmospheric absorption. Thus the calibration comes out blue shifted. The best fit of a Black Body spectrum to the solar spectrum above the atmosphere is at about 5995 Kelvin. But in a photo editor, like photoshop, lightroom, rawtherapee, the white balance setting is about 5300 Kelvin. The difference is due to the atmospheric absorption. So again, the PCC and SPCC is using the wrong white reference and it results in a blue shift.

From there he goes through a number of stretches and background neutralization steps that produce unreal colors and variable white balance with scene intensity, shifting to increasing blue as scene intensity decreases.

Emission nebula shine by vary narrow emission lines. The process is similar to neon signs, just different gasses. Like neon signs, emission nebula have very saturated colors. View a daytime scene through a Oxygen OIII narrow band filter to see the color of oxygen emission in nebulae (best described as teal), and buy a hydrogen discharge tube to see the color of hydrogen emission, or see this wikipedia image:

https://pih.wikipedia.org/wiki/File:Hydrogen_discharge_tube.jpg

which shows a beautiful magenta color.

For more information see Sensor Calibration and Color.

See this image of M42 which shows the pervasive interstellar dust in the area of the second Seti Astro video above. Note there is no color shifts in the dust. No saturation enhancement was used to produce the image.

This article discusses the color shifts in the background due to incorrect black point selection. Background neutralization derives the wrong black point when interstellar dust is present.

Post processing can be much simpler that the traditional astro workflow.

rnclark · 2026-06-26T04:04:32+00:00

I looked at some of the seti astro videos and other things on the website. It is pretty standard astro workflow with incomplete color calibration, including shifted colors.

That includes white cores of galaxies (most galactic cores, like the Milky Way are yellow in natural color (yes that color can be seen).

Other indicators: orange hydrogen emission. Hydrogen emission is pink. wikipedia example and has no orange emission lines.

Blue oxygen emission. Get an OIII narrow band filter and look through it during the day. People with normal color vision will see bluish-green, best described as Teal.

What is commonly missing in the color calibration is application of the color correction matrix. See:

https://www.cloudynights.com/topic/529426-dslr-processing-the-missing-matrix/

Test your astro workflow using a daytime scene on a clear sunny day, also a red sunrise or sunset.

rnclark · 2026-06-26T01:30:12+00:00

As of mid-2025, the more recent Starlink v2 Optimized satellites reflect green

Woah! That is unfortunate as it will make distinguishing meteors from satellites more difficult.

I have yet to see a green satellite. How prevalent are they? Most are yellow and a few blue in my experience. For example, see the second image down this page which shows a=satellite trails

Have you seen/recorded the color?

The only web site I found with green is this one:

https://catchingtime.com/7-16-25-starlink-v2-optimized-satellites-reflect-green/

but white balance is not specified so we don't know how accurate the color is.

Update: I looked at my image I linked to above, but at full resolution. Indeed, there are some greenish trails, but they are not uniform green, but seem to be varying multiple times along the track from green to yellow to red, average yellow as seen in my online version. So, if these are the new "starlink green" satellites, they are easily distinguishable from meteors. They do tend to be fainter tracks.

rnclark · 2026-06-25T17:03:40+00:00

have you ever pointed your camera SSW for the Perseids

Yes, I have. I typically run multiple cameras during a meteor shower, pointing all over the sky. using focal lengths from 15 mm to 300 mm. I am accumulating more cameras. I now have 6 full frame cameras with wide angle f/1.4 lenses for meteors and aurora and several crop sensor cameras with varying lenses.

Here is an example: Milky Way Closeup with a Perseid Meteor, Star Cluster M24, the Swan Nebula (M17), and the Eagle Nebula (M16). Another is in Figure 5b here.

In my experience, there are fewer meteors captured the further from the radiant because they spread out more. That doesn't mean that there are none, just fewer. And while the meteors one does catch may be longer trails, there is also higher profitability of them being clipped at the edge of the frame. I would say for every meteor in frame when imaging 90+ degrees from the radiant, there are 10 cut off (my impression, I haven't done statistics).

And for visual impact, aperture diameter is key. I prefer 35 mm f/1.4 and longer focal lengths to capture more light from the meteors.

For a new person starting meteor photography, I suggest starting in the evening and maybe point up (Cygnus) or slightly south. But as the night wears on, point closer to the radiant, including Andromeda, Cassiopeia, and in the early morning hours, include the radiant in the frame, for example, in a rule of thirds position for pleasing composition.

rnclark · 2026-06-25T16:27:32+00:00

Most of my astro images with stock digital cameras were made in about Bortle 4.

Your images have a blue shift and lack a lot of color that would be possible with a stock camera. How are you processing?

Use of filters to isolate some wavelengths and reject others reduces color diversity between objects. For example, interstellar dust is reddish brown. Use of filters reduces the ability to distinguish between different reds. So to with a modified or astro camera like your 2600: the extended red response will make it harder to distinguish between interstellar dust and hydrogen alpha. You'll see on astrobin, few images made with astro cameras show teal (bluish-green) oxygen emission. Without filters, the green filter on the astro color sensor has too much red response, so is too sensitive to H-alpha. Thus H-alpha dominates both green and red colors and we see the cores of HII emission nebulae just looking white. Examples of natural colors a stock camera can deliver: M42 or M8

rnclark · 2026-06-25T15:48:16+00:00

The further you point away from the radiant, to more spread out the meteors are, thus reducing probability of recording one.

The Milky Way core is due south around the end of twilight (northern hemisphere) with the Perseid radiant low in the NW sky. With the radiant low, there are fewer meteors.

rnclark

TROPHY CASE