ONIKKINEN

Link? Would love to read it (with popcorn, naturally).

Yes, or more specifically that mount but converted to equatorial mode like this: https://www.rothervalleyoptics.co.uk/skywatcher-az-gti-wifi-goto-equatorial-mount-head-package.html . The EQ conversion thing has to be done to get rid of field rotation from an alt-az mount, so just the mount wont do for imaging purposes. You can also buy all the accessories needed to do that separately (wedge, counterweight bar, counterweight). There is a lengthy thread here in SGL for users of the AZ-GTi, lots of information there. Take a seat though, the thread is quite long .

Your plan of a redcat51/milky way is very forgiving on kit so you have choices, the main differences are in bulk/price/reliability and future wiggle room for another scope if one day you want one. The SA GTi has had some growing pains being a new product. In various cloudy nights threads you read a not so great story so might be a risk. The price is a bit too high too IMO. Looks less bulky than the EQ3/35/5, but not by much if you couple it with a decent tripod. Have you considered an AZ-GTi with an EQ wedge? Cheapest option and will work with lens setups just fine. Least bulky too, but will not be exactly high performance or have much room to grow. Choices choices... One thing i am certain of, the EQ3 or the EQM35 are neither what you are looking for just because one is overpriced and one is just bad with more convenient options available.

Well, they are technically correct. It is possible to put a 9kg scope on the EQM35 and take an image. It will never be reliable and have proper guiding though, but no such claims are made so no legal issues with the statement of payload either. Neither will the EQ5 be good in that role, but it has potential to be much better so it is less of an issue IMO. Some details on the 35: It has no bearings on either axis, just plastic shims (yes, plastic!) and somewhat competently machined sliding surfaces for the axis to roll in. As such it will be impossible to adjust the wobble and backlash away, since when you approach the area of decent backlash you bind the axis in place creating other issues. The only real difference to the EQ3 is that the RA gear is a little bit bigger so it has a chance to have an easier to control RA periodic error. Doesnt matter though since the housing for the axis is bearingless, nullifying whatever gain the larger gear brought, and you will autoguide anyway so the periodic error is of little concern. For comparisons between the 35 and 5 the 5 will be a bettet mount 100% of the time. Take with a cartful of salt, sincerely a very unhappy previous owner of the scam that is the EQM35.

This is just not true. The payload limit on the EQM35 is based only on the counterweights it is supplied with. True photographic payload is 0-5kg, visual maybe towards 10kg depending on how much wobble you tolerate. The Skywatcher stated specs are pure hallucination.

No, absolutely not. The EQM35 is an EQ3 in disguise, the EQ5 is a completely different mount from its technical specs.

Agree, this wont change any time soon. As far as i know the 571 chip is being used in Fuji-XT something (on of the newer ones) and a Pentax something something, not sure about the model names tbh. Point is both of them are expensive premium models so they dont affect the sales of cooled 571 models at all.

Is this too much? https://www.firstlightoptics.com/zwo-cameras/zwo-asi-585mc-usb-3-camera.html This would be the cheapest entry in to the dedicated astronomy cam world, unless you find a good deal on an older used camera. Its not all roses however, you have less than half the sensor size and so also field of view compared to crop sensor DSLRs, but performance is likely to be much better. If you want to go cheaper than that then a second hand DSLR/mirrorless would probably work better. Next in line for dedicated astronomy cameras would be the 533: https://www.firstlightoptics.com/zwo-cameras/zwo-asi-533mc-pro-usb-30-cooled-colour-camera.html Getting expensive now though. Only goes up from here 😬.

Budget? Cooled (or not) astro cams are not so obscenely expensive anymore, how much you want to spend and what use the camera will get (DSO/solar system) will determine if a DSLR or an astro camera is the way to go.

There is a slight error in the recommended workflow you mentioned, and where i think your colour calibration took a wrong turn, and that is the PCC/BE order. Technically you could do it either way if both processes work perfectly, but in practice you should always feed PCC a gradient free image so that it can have the best chance to succeed. Here you first ran PCC and then removed the gradient, which also affects colours a little so you kind of undid the calibration. With the Asinh 1000 i do adjust blackpoint a bit, but of course no clipping. The median filter option is a very crude way to denoise an image and will blur detail and noise in a 3x3 area, best to avoid and use denoising with Gimp somehow. Not sure how to as i dont use Gimp but there has to be a way, its such a common image editing feature that there is no way it cant be done (or a plugin that does it). Binning is a bit of a minefield to discuss online, you get many different opinions. But binning is the opposite of drizzling in that you increase the size of a pixel opposed to decreasing it with drizzle. So if you drizzle x2 you half the signal to noise ratio and make the image 2x worse and 2x larger (with no extra detail in 99% cases), if you bin x2 you double the signal to noise ratio and lose no detail if the image was oversampled (or taken with a colour camera in most cases for complicated reasons, best leave it at that). Most people ignore all of this, up to you to decide whether its important to you.

Were you expecting something like this as a result? Did very quick processing only, certainly not a full process. Looks like Siril photometry servers are down or something, i cant get it to platesolve and also cant get any of my other images to platesolve either (which previously of course have platesolved). At first i binned the image x2 in ASTAP to what i think is better sampling and higher SNR. So the workflow for this image in Siril was: Crop artifacts and generally for nicer framing Background extraction Manual color calibration with the core as white reference, works out ok for M33. Photometric CC would probably turn out a little bit different but cant do it now. Asinh stretch at 1000, this greatly stretches colour while keeping the balance ok Histogram transformation for the rest In Photoshop: Selected background pixels only, desaturated and denoised them Selected signal pixels only, saturated them by +30 NoiseXterminator Levels adjustment for blacks Very simple processing only here, i think you may have tried too hard with your list of things, and have done them in incorrect order. Generally the siril workflow should always go in the 1-5 order shown here, with 4 and 5 optional, but i recommend doing the Asinh 1000 stretch first if you want colours to be nicer in the end. In many cases doing SCNR green is required, was not for this case. If it is required do it AFTER the Asinh 1000 stretch but before the final stretch so not every bit of green goes away. If you incoporate starless processing in this workflow, dont stretch the image fully in step 5, leave a bit of wiggle room for later. You can drop deconvolution completely, the Siril tool only works with very high SNR images, which this (and most others) is not, and even then its not that good. Canon banding reduction should be done on the calibrated subs if necessary, its too late to do it on the stack as the banding is no longer horizontal or where it should be. I dont think its necessary for this image at all, you're not going to stretch it far enough for it to matter (at least i did not). The generalized hyperbolic doodad is great at killing colour, use at your own risk. Avoid if you dont really need it, like in this case where the dynamic range required to show the object of interest isn't really that difficult, an image with IFN or some faint nebula with background signal everywhere is another matter. The contrast limited histogram thing is not really something you need either, in this image or in general. Do fiddling with contrast in PS/Gimp later where you can place the adjustments exactly where you want to with layers. Also the median filter is a strange choice, you deconvoluted the image assumedly to emphasize detail, but then you went ahead and blurred it all out with the median filter? If the image is noisy, deal with it later or bin more. There is a bit of chromatic aberration visible here in the brighter stars, i think you may want to consider placing an actual UV/IR cut filter somewhere in the imaging train. The astromod, while not full spectrum since only the rear filter was removed, probably passes a little bit too much deep purple and red.

Ah this menu, looks about the same, without the bayer pattern and MonoBin options since the camera is mono. Nothing unusual there really, just a gain setting with low,high and manual presets.

Does this mean no filters of any kind, even a UV/IR cut one? Also i guess the method of modding would affect how deep into IR the camera sees, if im not mistaken there are full spectrum mods and mods where the stock IR cut filter is replaced with an astronomy useful IR cut filter that passes to 700nm or so but not further. The reason why a full spectrum pass is a problem is because most bayer matrix filters turn completely transparent somewhere around 800nm meaning that it turns monochromatic and will destructively affect your colours. Its essentially diluting your colours, specifically the blues since there could be a lot of near IR signal posing as blue in the capture. Alternatively, something went wrong in processing. You could post the linear stack (before any processing has been done) and others could have a look if something went wrong.

Does this make sense to you? Few of those options are mysterious to me. Gain and offset pretty self explanatory (also measured offset to be 3200 in 16-bit value so 200 in 12-bit), but the others not so much.

Ah, looked a bit familiar but couldnt tell from where in the sky. Actually have had a chance to image anything in Orion only twice since 2020 because its so low in the sky at my latitude of 60N. But in case you want to be thorough you could help yourself by measuring the fwhm of your unsaturated (small, background stars) stars. In decent seeing you should be getting close to 3" stars or below, in not so decent maybe towards 4". If you are urban and you have houses nearby messing the seeing then all bets are off on that. The only thing you could adjust and maybe get an improvement is the backfocus of your CC, which is difficult to tell because the sensor in your 533 is so small the edge artifacts dont show up. In my APS-C sensor i noticed not only edge stars getting sharper but also on-axis stars with adjustments to backfocus distance. Star sizes indicate if its worth pursuing, probably not.

Looks like a working newtonian to me, dont touch anything and hope it stays like this. Stars look maybe a little bit big, but this was probably the seeing or these are just bright stars (dont recognize the target) so probably nothing you can do anything about.

I did some of the measurements (did not take into account darks or the effects of read noise, the results seem within acceptable limits without) and found that at Gain 110 i get an e-/ADU conversion of 0.63e-/ADU, close to the ZWO values and within the margin of error for sure (close enough for me). At Gain 40 i get 1.38e-/ADU, again more or less in the ballpark. Here is where it gets interesting, i had to switch from the native ZWO driver to the ASCOM one because the camera kept freezing and i had difficulty actually capturing the frames to be measured and got annoyed at having to reconnect the thing. Then after having calculated the 2 different gain values i decided to run sensor analysis on the ASCOM driver, just in case and look at this: COMPLETELY different result, as if taken with another camera completely when compared to the native driver measurements. This is really bizarre, almost like the native driver works in some kind of higher fullwell low conversion gain mode where as the ASCOM driver version looks like one would expect from the ZWO graphs. Then after some struggles i managed to make a measurement on the native driver at Gain 131 and measured it to be 0.72e-/ADU which is close enough to the original measurements. So in conclusion, the camera has wildly different behavior depending on the driver used. And also, finally answered my original question as to what gain to use. 106, like reported by ZWO, for the HCG mode to activate in the ASCOM driver. Not a clue whats going on in the other driver, im going to stay away from that. And here is what i mean on which driver: The ZWO ASI220MM Mini option results in the higher fullwell results, the ASI Camera (1) option results in the expected result. Also, PHD2 will only connect to the ASI Camera(1) option, so no option to use the "wrong" one even if i wanted to.

Looks like RCS thrusters firing for sure, the pulse in the beginning at least. The spiral one could be de-spinning a spin stabilized spacecraft or spinning one up for a burn, if its backlit by the sun it will be easily visible like this from Earth.

Ill give this a try later, never thought about how its actually done. I am assuming offset/dark subtraction and a 16-bit to native 12-bit conversion has to be done so that the measurements and results make sense and only real signal is measured?

There are also the IMX461 based medium format cameras, or the GSENSE4040 based ones, both around 50mm+ diagonal. Still costs about as much as a decent car, but nothing compared to the 700mm RC so almost a good deal at 10k£ (at least).

I could definitely set it to at least 200, did not check how high it could be set as the very highest gain settings make little sense for guiding. By the way there is another confusion here, the gain goes up to 600 even though the sharpcap measurements and ZWO diagrams end at 400. Go figure.

Really stretching the definition of the word game changer here. Was there an issue with WO focusers, i thought they were good quality already?

Something inside the scope obstructing the light path, like a shiny screw or similar? Could be pinched optics too. Weird diffraction spike threads appear every now and then and often there isn't a solution 😮 . I have an extra diffraction spike on my newtonian, but only sometimes, and only on some parts of the image much like yours. No clue what is the cause, i am guessing some kind of pinching but have not bothered to figure out. The diagonal noise is walking noise, which partly goes away with taking and applying matching darks and completely goes away if you dither every now and then.

It occurred to me that ZWOs own capture software ASIcap has an electron per ADU readout that i believe is read straight from the driver as its not doing any measurements. I find that minimum gain is reported as 4.96 e-/ADU, unity gain is at gain 139, 0.5e-/ADU at 199, 0.25e-/ADU at 259. So its looks like none of this agrees with any other method. ASIcap is closer to my measurements than the reported ones, but its still not close 🤔.

My VX8, from the opposite end of the price spectrum so maybe less of an issue, came with a non round tube (it was squared on the secondary end and triangular on the mirror end because of the attachments bolted to the side of the tube), a bent secondary spider, a secondary mirror that was physically impossible to collimate because a) collimation screws were too short, b) the spider was drilled to the incorrect position, c) the focuser was drilled to the wrong position, d) a bit of all. (secondary mirror could not be brought under the focuser = true collimation impossible) Just a glance down the focuser tube and an attempt to bring the secondary correctly under it would have revealed the action to be impossible so this begs the question, was it assembled by a moron that does not understand how the product was obviously flawed, or was it assembled by someone who knew it was flawed and did not care to do anything about it, or third option: did nobody actually look down the focuser of the telescope to check that they are shipping a working scope? You tell me which one of the options is the least worst... Anyway, not a company i will throw any money ever again even though the scope worked out ok in the end.