skybadger

Or thread a 2" adapter into the body and use a 2" to camera coupling which allows rotation too.

Things like the difference in balance due to asymmetry in mounting and less than perfect 3d balance causing different loadings on the gears dependent on its position in the sky. I agree that perfect mounts would take best calibration from Dec 0 due to the cos factor but , for me at least, I get better calibration nearer the target.

I wouldn't be happy with the advice to calibrate PhD at dec0 myself, the mount imperfections on either side of the pier are greater than the calibration imperfections . I know I get much better guiding if I do a quick recalibrate near the target, as long as the target isn't too high in dec, if it is, pick a target with a lower Dec but on the same side of the pier.

It's not longer subs , it's more frames leading to more of higher quality to stack to get critical detail.

Do a quick search here, there have been similar topics before but in summary, watch out for the IR leds, they can cause grief while imaging. Otherwise any IP camera will do, I haven't found I e yet sensitive enough to use without illumination of some kind.

The cloudy nights ascom controller for DSLR will control this up to 30 seconds per exposure. For longer you need the ir remote which is a few pounds on Amazon. There are a couple of projects to automate this but I suspect the intervalometer you have will do that job already. The unit needs to in front of the camera and visible to the IR sensor which is a bit more difficult when it's close up to the scope.

What was the gain set to at capture time - high?

That chip fat is the right grease for the worm wheel ... But not necessarily the rest of it. I redistributed mine on the worm and left it at that. Works well.

I've done the mod to put a dovetail either side and put steppers on both axis driven by an onstep to track the stars and do goto, principally for solar and mobile observing, with a stellavue80 on one side and a vc110 o. The other. Works very nicely.

Mine stays on permanently in the obbo, as much to keep damp out. Since they are quite low power in suspended mode, it's enough.

I wouldn't say much higher, I'd aim for slightly higher than expected if all other factors are in your favour. Id want to sample at at least 2x the Dawes resolution per pixel. if Dawes is 0.6, aiming for better than 0.3 per pixel to make sure you don't miss anything. You can focus on a moon or a star to get focus right for each wavelength.

Thanks for reminding me. In that case you don't need the spacers at all. It is fair to say that your 2000mm focal length and x4 powermate are overkill for this and can probably get away with nothing at all; hence the mushy focus. Sample images ?

You only need to get the Barlow in place and a detector behind it. You don't need the filter wheel or spacers unless you want to increase the magnification of the Barlow by increasing the distance between lens and detector. You shouldn't care about the detector being at a particular position, just focus. The position will be different than at prime focus due to using the Barlow. The problem of soft focus is nothing to do with the Barlow other than it magnifying what your scope is capable of. You could check collimation at this point or reduce the magnification slightly, get some video for stacking and see what comes out. Was it soft in the eyepiece or the camera ? If viewing on a screen, the image is quite magnified so will be soft for lots of reasons including scope cooling and seeing.

Those are fine work. Can you tell me what you did to produce the maximum stacking combination please. Impressed to see the satellite motions.

I had an extended session on this last night using my vixen na140. First to find it, next to image it without the centre being overexposed. I was taking 0.8 second images at 1x binning so I mostly lost the other fainter field stars. The Goldy straw colour was prominent even in the haze. I may try for a spectrum tonight..

Hi Wim, I replaced the guts of my old davis station with an esp8266-12, the wind speed sensor just provides a digital counter input on pin 14 and the direction sensor comes in via Adc0. Using the bme280 means the expensive mlx part is not used. Added a hygreon rain counter on another digital pin and it drives the ascom observing conditions monitor in node red. It's a neat and tidy solution using the esp.

I have one. In white so probably eq5 rather than vixen . Interested ?

Thanks. I'll give that a go with some images I'm trying to get.

The asi178 is uncooled, how do you manage the amp glow ? Is that why you limit exposures to 30 seconds ?

Did you find the group's.io forum for MoM ? It all used to be on yahoo groups and then moved over.

I'd forgotten that. It was a sight.

Image scale in "/pixel=206265/focal length in mm . Turn that into "/pixel by multiplying by pixel size in mm Field of view is "/pixel X # of pixels on sensor. Tracking accuracy is whatever you measured, so yes you could shoot for 9x longer but why not put the wide field camera on the narrow field guided mount and get the best of the guiding ?

Hmm, the ability to image at pace feels self limiting on the size of image files BC you can't download them fast enough. You could do it all offline though. Say 3600 1 sec images of an object by 4 MB per file by several hundred imagers ? Each night. I'd be looking to pipeline this through dynamic cloud services (lambdas) and auto stack when a pipeline is quiet for longer than say, half an hour. Use central coords of image and return list of all folders in operation when someone wants to know what subjects are bing imaged. Just thinking aloud though.

Tx Rory. So the intent is to aim for one or two second exposures then. Lucky imaging it is.

I'm really interested to get clarity on what the aims are. It seems like it's to have high resolution, high snr images using small/amateur sized telescopes. The issues I see are tracking - what exposure length makes tracking errors below the target scale seeing - can we get enough pictures sampled better than the target scale resolution, by combining pictures from smaller scopes can we get sufficient snr to discern and resolve features approaching images from larger scopes collimation - can we educate enough people to get the most out of their systems to contribute. optical errors - can we combine images from a huge variety of image scales and their specific optical aberrations and combine the images in a meaningful way, that is not disproportionately compute intensive. Do current generations of stacking programs model the image plane aberrations for stars in each image as part of the stacking process or does this require a new approach ? Have you got a feel for this new approach ? Finally, what is meant by 'lucky imaging'. In planetary it's all about freezing the seeing to remove the atmosphere from the optical limitations and stacking those few high quality, single-sourced images. In low snr, long exposure deep sky , you must mean something else right ? it's not lucky imaging if you are still exposing at 30 seconds per shot because you haven't broken any of the limits outlined above. I'm not knocking any of this, crowd sourcing imagery and pipeline processing is a great tool; just trying to understand the headline aims and the underlying physics. mike