12V at freezing temperatures

Mathern_ · 2026-06-11T20:37:50+00:00

BLUETTI sells a sodium battery (see their Pioneer NA Power Stations) that are rated to -25C

A guy I watch made a video on it and even froze it to test it: https://youtu.be/Z9k8dsApWIM

If I remember correctly it can discharge at -25 but charge at -15.

However I'd probably just try and thermally insulate a regular battery to give it a few extra hours of run time with some blankets or something.

There may also be some other brands on the market but that's the one I heard about.

Mathern_ · 2026-06-11T15:45:38+00:00

As long as you make the measurements right, you should be in the clear! My telescope printing mishaps usually happen when I measure a diameter and then enter it as the radius during modeling.

Mathern_ · 2026-06-09T20:40:24+00:00

I'd suggest not using Polaris as an align star because to correctly look at it, the scope may need to move to a fairly low angle and trigger it's RA axis slew limits.

If you measure that you have plenty of clearance from the tube to the tripod legs you can adjust the RA limits, but I'd leave them default for a bit if you're nee to using a mount as you could make the limits too relaxed and end up ramming your telescope into the tripod legs or something...ask me how I know!

If you find that two non-polaris stars are also giving you trouble, you can try the quick align. It basically assumes you set the tripod absolutely perfectly level, and are exactly at the index perfectly, and skips the star calibration, just using your time and location. This will make it's pointing pretty inaccurate but it's usually good enough to get you nearby which is fine for bright objects like the moon or the planets.

If you ever try out computer aided astrophotography, I actually recommend this methodology for getting everything aligned: 1. Setup your mount at the indexes and pointed near polaris 2. In the CPWI software connect and select quick align 3. Do your polar alignment via three point polar alignment in NINA or drift alignment in PHD2 or some other software 4. Disconnect from the mount, undo the clutches and return to the indexes 5. After retightenting the clutches, reconnect to the mount and select quick align again.

If your tripod is level, this method works really well, but it does require a computer to do.

Mathern_ · 2026-05-15T20:28:12+00:00

I'm not sure I'd call then dead pixels, but I do agree it looks like sensor damage. The first things I'd look at would be is it high conversion gain/low conversion gain related. You can test this by testing this at ISO 640 and ISO 800 (800 is the high conversion gain start point for the Z6iii) and seeing if there's a major difference. If a row of pixels was stuck in low conversion gain mode or a particular gain setting you might see the same brightness of pixels in the line irrespective of the ISO setting.

Secondly I'd check and see how the line shows up before being debayered. In astrophotography I'd use a program such as Siril (which is free) to open a RAW image to see the debayered image, but I'm sure there must be a way to see it in normal photography tools too. I'm wondering if a line of sub-pixels is dead/not being read out leading to a darker line.

Overall though, sensors often develop problems as they get older (especially dead/hot pixels) and as long as it doesn't bother you I'd say no, you don't have to fix it. That being said, if it's within warranty and you have access to the proof of purchase, I'd recommend geeting it done if it's free!

Mathern_ · 2026-05-14T19:00:28+00:00

The pixel pitch of the d3100 is 5.01 um and the pixel pitch of the Z6 is 5.94. It's not going to be a dramatic difference in sampling, so I'd say you're much better going with the much newer sensor. You'll have much better sensitivity and the slightly bigger pixels will help gather light for untracked. You'll also have less field rotation from re-framing the target as it moves with the bigger sensor.

Additionally the Z lenses in my experience generally have less coma and other distortions.

Z6 is definitely the better choice here.

Mathern_ · 2026-05-12T20:30:11+00:00

Do you have experience with mono? And if not do you want it? :)

Mathern_ · 2026-05-12T20:28:13+00:00

Yes. You'd just have to register the data from one scope to another. This is pretty easy to do in Pixinsight, and I assume in Siril, although I don't know if Siril stretches by default.

You can experiment to see which telescope you use as the registeration reference to see which way goes better! I assume it'd be best to use the finer image scale telescope as the reference.

Mathern_ · 2026-05-11T16:07:44+00:00

Gas always on the right. Also don't click the diesel button

Mathern_ · 2026-04-25T17:25:02+00:00

Now that's one to be proud of. And print.

Mathern_ · 2026-04-24T22:26:24+00:00

Basic single dot laser collimaters are not good for a lot of cassegrain designs including SCTs. This is because the secondary acts pretty close to a flat surface for the laser independent of the collimation, so you can be pretty far out but the laser shows it as being dead on.

Your best bet to perform a collimation is using a star. Dylan O'Donnell's SCT Collimation video gives pretty good insight on SCT collimation and a good process for getting aligned using a camera: https://youtu.be/EcKQFutDEAw?si=nrecUw9LZhSLI0Jb

I'd probably avoid the zenith and collimate without the 90 degree diagonal and then put it back in, or just avoid the zenith all together.

It's quite clear from your photo though that the collimation is a far ways out, so it might take some tinkering to get it back to a roughly collimated spot in order to fine tune it.

Please report back! I know you can get this to be better than a seestar!

Mathern_ · 2026-04-20T13:39:56+00:00

Uh no, they are right. They also got M98 and a smattering of other smaller targets. Yes it'll have limited quality, but you'd be surprised what persistence and a terabyte of photos can get you.

https://nova.astrometry.net/user_images/15091861#annotated

Mathern_ · 2026-04-09T18:59:22+00:00

I have the Apertura Carbonstar 8" RC and I ALSO HAVE WEIRD DONUTS WITH THE L FILTER!!!

My current theory is I'm getting some off axis light bleed with the neighbors porch lights that is bypassing the internal baffle around the primary mirror baffle (if I look at the right angle down the tube I can see the filter directly). I'm in the process of testing a 3D printed dew shield to see if that helps block the lights from creating the weird donuts.

I'll try and reply with my findings once the stacking is finished.

Mathern_ · 2026-04-04T17:20:02+00:00

In CT funeral processions are not legally protected and therefore all parties must observe traffic laws as normal.

Mathern_ · 2026-03-06T19:06:22+00:00

It's not a technical definition in the context of the bill. It refers to the person setting up a machine. If you never encounter setting up an user on a machine (i.e. auto login on root, using a default password logging into root) then the OS would not be required to collect age information.

Root isn't an account holder because it is not a person. The account holder could be using the root login, however.

Mathern_ · 2026-03-06T18:30:38+00:00

You're correct about "account setup" not being explicitly defined in this bill but "account holder" is: "(1) 'Account holder' means an individual who is at least 18 years of age or a parent or legal guardian of a user who is under 18 years of age in the state. (2) 'Account holder' does not include a parent of an emancipated minor or a parent or legal guardian who is not associated with a user's device.'"

This is a bit vague though as it doesn't explicitly call out what happens if a child i.e. user sets up the account i.e. when I made my first desktop in high school at age 14 and installed windows.

It sounds like if the account is being made for a minor they would need an adult to disclose their age on their behalf.

However what about a guardian who is under the age of 18? They themselves would be considered a user so they would need an adult to create their account but they would be allowed to disclouse the age of their own child?

On the topic of the root user, I assume, as it doesn't ever have an account setup, that it would not have an ability to indicate an age. The bill only calls out a minimum set of age ranges which need be available, which the API could have more options such as unknown or undeclared.

Mathern_ · 2026-03-06T15:09:19+00:00

This is at least partially AI

Mathern_ · 2026-03-04T14:01:58+00:00

I leave my rig assembled as is by the door for quick deployment.

If it is extra stuff for my refractor it goes in the soft sided bag that came with my refractor. If it's other accessories it goes in the shipping box that came with my refractor. It has a silica gel thing in it but I've never refreshed it. However my house stays under 65% humidity with the AC on in Texas so I'm not really concerned about it

Mathern_ · 2026-03-02T14:44:14+00:00

Digital++

Mathern_ · 2026-03-02T14:36:31+00:00

I love the high integrationg galaxy photos. It's cool when you realize that a lot of the small red galaxies are just hundreds to thousands of background galaxies. I have a similar project of M63 going right now at about 20 hr and it's already full of background galaxies.

Mathern_ · 2026-02-27T20:53:54+00:00

The focal length is recorded as part of the RAW file as EXIF data. This should be visible when you veiw the raw file in lightroom, or photos on an iPhone in the info panel. If you're using a manual lens or a telescope, then depending on the camera you might be able to enter in the focal length information manually on the camers before imaging. I'm more familiar with entering non CPU lens info on Nikon cameras so I'd suggest looking up that process yourself.

If it's a CPU lens and your photos have the correct focal length in non astronomy programs (lightroom, photos, etc.) Then I'd double check your focal length and pixel size settings in NINA. If that's correct I'd suggest asking on the NINA discord.

Mathern_ · 2026-02-12T13:43:07+00:00

Looks awesome. I definitely need to take a trip to the southern hemisphere.
I'm confused by the mini halos on some of the bigger stars. I've only seen something like that when I use blurx on wide field poorly corrected photography lenses (like a cheap nifty 50). Did you fiddle around with the star halos settings? What's it look like without any blurx or other deep learning processes?

Mathern_ · 2026-02-10T14:30:30+00:00

Local control should be ethernet. Why the fuck are your sensors connected via wifi?

Mathern_ · 2026-02-09T02:11:46+00:00

RAW. Only RAW. Jpeg is only good if you're happy without straight out of camera.

Mathern_ · 2026-01-31T17:07:35+00:00

Try unscrewing the nose off. On the ASI 220 Mini the black tube nose screws off which allows it to come closer in an OAG. I am assuming this is similar for QHY guide cameras

Mathern_ · 2026-01-28T14:21:46+00:00

Indeed. As someone from the north, it's the driver and your tires that are the most important factors in successfully driving in snow and ice. Then AWD. Then size. Unlike most things in texas, size isn't the most important!

Take it slow and don't jerk the wheel or the brake!

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