michael8554

You should already have inline fuses for your mount and other equipment.

If the peltier has a fault it shouldn't harm your mount if connected in parallel.

But an unfused short in the peltier circuit could lead to thermal runaway.

Michael

I've converted many Canon DSLRs, and used to measure the sensor-to-mounting plate distance at the three Torx screws with a digital micrometer rig.

Now I mark the screws and mounting plate, and record how many Torx "points" it takes to fully tighten each one.

On reassembly, fully tighten, then back off the required amount.

Michael

My intuition is that with a Bahtinov, a point source is best, not an Extended Object like a planet.

Why ?

I but would expect the 6 spikes to be ill-defined on a planet.

Michael

Best to focus on a star, not a planet, with the Bahtinov Mask.

Michael

Nice.

But why not the usual red leds, to help preserve night vision ?

Michael

I like William's explanation.

Though your post heading talks of Collimation too.

If that is badly out, not just the focus, I would start with a Collimation with a high-power eyepiece.

Michael

The GPS won't pickup satellites indoors.

Michael

Does the shutter fire with no lens or T-Ring attached ?

Have you set exposure and focus to manual ?

The camera may be trying to connect to an autofocus lens.

Michael

As wookie said.

A lot will depend on how light-polluted your sky is.

Michael

If the telescope has the two rings that clamp around it, and the bar they attach to.

Then you should be able to attach the bar to the moveable head of the Velbon tripod.

But I don't believe that would be stable and safe enough.

I think realistically you need a new or used Equatorial or Alt/Alt mount and tripod.

Michael

Facebook said ?

Be prepared for reports of hordes of zombies stumbling around during Totality, because they've forgotten to take their solar spectacles off........ 😆

Michael

The room looks like the King's Observatory at Kew.

Commissioned in 1769 by King George III, who was interested in astronomy.

To observe the Transit of Venus, predicted to occur that year.

https://www.kingsobservatory.co.uk/

Michael

The Altair Astro Starwave 66 ED-R is a Refractor with a focal length of 400mm.

Measure 400mm from the doublet front element.

That's where the scope focuses, that point does not move when you alter the focuser.

The focuser merely moves the camera or eyepiece to that focus position.

You may need Extensions to place your camera or eyepiece at that focus point, if the focuser runs out of range.

Michael

Found them.

In one of the earlier boxes.

What idiot put them there.......... ?

Michael

I've been replacing the five suspect capacitors in a Classic LX200, which requires some disassembly.

I keep the groups of screws in separate closed boxes, but the tiny screws that hold the RA and Dec boards onto the motor are nowhere to be found.

I remember removing them, after that it's a blank :-<

Michael

Two possibilities:

1. You have guiding with RA and Dec errors very similar  RA = 0.33arcsecs, Dec =  0.36arcsecs.

That should yield round stars.

But I notice a 1 arcsec spike in RA and Dec, so what are your RA and Dec Peak errors ?

2. Diff Flex occurs when you have good guiding figures - so the guidescope is being well guided.

But if the guidescope is wobbling, such as due to soft-tipped screws in the guidescope rings, or a wobbly Finder used as a guidescope, or cables dragging.

Then the imaging scope is not being guided the same as the guidescope.

Remember your imaging camera has pixels with dimensions in um.

A wobble less than the diameter of a human hair will elongate a star image.

Michael

"I've read that the small pixel size of the RPi HQ camera is an issue when used as a guide camera."

It's not only the pixel size that matters.

It's the combination of pixel size and focal length, which gives you the pixel scale.

In this case 18.05 arcsecs/pixel.

You'd have to go much much smaller in pixel size to get a usable pixel scale.

Binning, if possible, would make this worse.

A 50mm or longer guidescope focal length is required, to give a pixel scale of under 6.

Michael

The length of your exposures seems to be limited by PA.

Do your best with the polarscope.

But however good you get that, just use the DARV PA method to improve it.

That's all you need to do with your setup, then get imaging !

You had 4 pixels of RA in 5 minutes, so 75 sec exposures may be tops, if you get Dec to a similar figure.

Michael

"out of date polarscope".

Do you mean the tiny dated offsets don't go up to 2024 ?

If you're doing Visual, then guesstimate how far inside the inner ring Polaris has to be for 2024, and use Kochab's Clock, or an app, for the radial position.

Same for Imaging, but improve the PA with Drift Alignment.

Michael

The CR2 stars are elongated horizontally approx 90 pixels, and about 4 pixels vertically,  in 500 secs.

Judging by your Orion image, I'd guess that Dec is horizontal ?

So 90 pixels of PA drift, and 4 pixels of PE error.

"my polar alignments were repeatedly bang on in synscan."

How many arcmins of PA error was "bang on" ?

Michael

You should take single shots of increasing duration until you perceive elongation in the sub.

Then use the duration that didn't elongate.

Leave the 600D on ISO 800 and only reduce the exposure duration if you have light pollution problems.

Michael

PHD2 has two more PA routines as well as Drift Alignment, both when pointing toward the NCP.

Polar Drift Alignment, and Static Polar Alignment.

Michael

It's relatively easy to see if the ST4 cable is faulty by looking at the  guiding behaviour in the GuideLog, if you're using PHD2.

"Anyway it was still there to the side of garage"

What is "it" ?

Michael

Do you mean that stars are distorted in some way ?

Not unusual at the edges of the image.

Switching on LiveView 10x will "zoom in" on the central part of the image, where stars might be undistorted.

The edge distortion is not unusual for camera lenses when shooting stars.

You don't notice the distortion on the daytime images they were designed for.

Michael

I read that the focuser has:

"S58 Dovetail ring-clamp built into focusing tube for accepting optional T-2 / M48 / M68 and other S58 direct thread adapters to enable direct thread connection of accessories and cameras without 2" clamp"

And the MPCC has M42 threads.

Should be possible to screw them together ?

Michael