Stub Mandrel

This is something I learned the hard way, especially if you want to drizzle in AS!3. I now always debayer in AS!3

Looks nice to me. I popped a screen grab through 'gradient exterminator (using a selection excluding the nebulosity and with balance background ticked.) I then used 'selective colour' to reduce cyan in the red channel - a tip I got from Olly. More aggressive use of gradient exterminator, than a few runs of 'increase star colour' - some lovely blue stars appeared. Great data 🙂:

You need to use the same reference frame for all images. It doesn't matter if the reference frame is (e.g.) Red and you are stacking Blue, just uncheck it and check the blue images and tell it to 'stack images'. The unchecked red frame will be used as refernec but not included in teh stack. This will align them all the same.

To me it looks like it hasn't been debayered.

I aready have ZWO RGB filters and a filter wheel...

I think my worry has been is that with apparently 'similar' settings - maximum gain (to allow shortest exposure to fight seeing) and the display settings (brightness, gamma all on default) - the mono cam + a colour filter has appeared much less bright for a given exposure than the colour one. Now I know this isn't actually a problem and I can compensate by turning up the display brightness to compensate (effectively mimicking the extra gain) and rely on a combination of Sharpcap's Histogram 'brain' to ensure I keep the planet part of my data out of the 'red zone' while keeping the exposure as short as possible. It also give me the confidence to try again on Venus with my extreme UV-pass filter.

Diffuse and rather low daylight. See if I'm getting this right? As (in principle) the only difference between the sensors is the bayer filter the QE should be the same and to a first approximation, the mono cam will collect about three times as many photons per pixel per unit time. Any other differences come from the electronics. So let's assume that at a particular level of white light you get 100e on the mono cam and 33e on the colour. At their maximum gains this gives 213 ADU and 305 ADU respectively, so the colour will appear over half a stop brighter if these are scaled directly to display levels, even though the mono image has three time the 'real' qauntisation depth?

I've managed to get some comparative results for my Touptek Mono: And ZWO ASI120MC: These both use the SAME chip, and I would expect the mono version to be more sensitive, but in Sharpcap it appears LESS sensitive. I THINK these figures explain why - the ZWO has much higher gain giving the apparently 'brighter' image, but at about 0.1 e/ADU this is at the expense of dynamic range and not actually giving me more data. The mono cam has a sudden drop in read noise at 200 gain - I assume for long exposures this will be the best setting balancing noise against dynamic range. Note both cameras were very warm (about 27 degrees) for this test. Can anyone help me better understand these figures?

Has anyone got a Toupcam to work with Sharpcap and Toupcam drivers? I can only get mine to work with the 'GPCAMAR0130C' driver and the results are disappointing.

Thanks @vlaiv that's useful food for thought.

ED 66 66mm x 400mm 130PD-S 130mm x 590mm (with coma corrector) 150PL 150mm x 1200mm Using the f/3.6 rule, I get optimum pixel sizes of 1.68, 1.26 and 2.2um. If I use a 0.5 focal reducer these pixel sizes halve. The ASI 183 has 2.4um pixels and the ASI1600, 3.8um, to me the ASI183 seems better match? I know there are other ways of calculating the optimum pixel size and it depends on seeing & guiding as well. On all but the 150PL my RMS guiding on a good night is <=1 pixel with the ASI183. With 150PL I'd experiment with binning in processing.

I am agonising about this. The ASI 183 is better suited to small DSOs with a pixel scale very well matched to my scopes, and offers potential for binning while still keeping a decent final image size. The smaller sensor means any residual worries about field curvature with my frac evaporate; I could also use my 0.5x reducer to get a wider FOV so it could effectively frame anything the ASI1600 can. The ASI1600 has a bigger FOV but will undersample and would not suit tiny targets. But these differences are marginal. The issue seems to come down to the amp glow of the AS!183 versus the microlens artefacts of the ASI1600. Any purchase is some way off, but I like to have an 'end in view' and a decent cooled CMOS mono cam is pretty much where my upgrade path can end -aside from finding better skies... It is an agonising subject to debate.

Hi Wes, I image planets with a 150PL an x3 barlow, a filter wheel (left on IR/UV cut for my colour camera) a ZWO Atmospheric Dispersion Corrector and a ZWO ASI 120MC. There isn't really a magnification for imaging, it depends on focal length and pixel size, but my equivalent focal length is 3,600mm which is quite long. I hope to make an equatorial platform in time for mars next year, so i can use my 10" dob which should start to open the door to some good results.

I hope so - looking at my results I started when Jupiter was in Orion using webcams. Each year my gera and technique got better but Jupiter got lower and my image quality stayed more or less the same. Hoepfully over eth next six years both my skill and the seeing will improve together!

From the MSDS: " The identities of the materials in this product are withheld as a trade secret (29CFR1910.1210(i)) and are available to a physician or paramedical personnel in a emergency situation." It's always worth a try googling <product name> MSDS. bear in mind that the fundamental solvent is only going to be one of a fairly liomited range of options, it's the additives they keep secret.

I wouldn';t expect (from experience) a cheaop x5 barlow to be any good. There are 'mid price' x3 barlows that are worth using. My Revelation Astro ED Barlow (x3) is very nice. I have an x3 insert of 'unknown origin' that came from Astroboot and it performs very well for imaging.

It's embarrassing to post my pics in the same thread as Darryl, but in my defence these are all with Jupiter about 15 degrees up with a 150PL... 28 June 2018 the 'split' is over 1/4 of the circumference: 20 July 2019, no sign of it at all:

What's even more amazing, is I putt the URL of your image into Astrometry.net and got:

Service interval : 10 billion years. Should be good for a few miles yet.

There are some startling examples on Cloudy Nights - patterns of circles radiation out from stars. They seem to be associated with a combination of filter spacing and micro-lenses.

I think this must be because the ease of CMOS imaging tempts people to tackle ever more challenging images. Even with short exposures I rarely manage more than 4GB of data in a night with a DSLR, which produces similar file sizes.

As awesome as ever! With about five years to save up, can you remind me what your imaging rig is - I know you have a C14, but what's the rest of your imaging train?

With them so low I think local 'hot spots' make a big difference to the seeing.

It is incredible. I am excited about what might will possible when the planets are higher up in the sky.

Hi, @iwols, a 150PL on EQ5, unguided. ZWO ASI120MC camera. Between scope and camera are: X3 barlow element, filterwheel set to IR/UV cut filter (probably not doing anything) and, most importantly, a ZWO ADC set almost to 'max'. I focused using a Bahtinov mask on a bright star. I took lots of runs of 5,000 frames for the planets, but the moon one for the above was only 1000 or so. For both Saturn and Jupiter most results were pretty similar but then there were one or two images noticeably better than the rest. In SharpCap I found it was necessary to use 100% gain and accept longer exposures and hope for periods of better seeing - at f24 you really aren't getting a very bright image! Pre-processed in PIPP without debayer, stretched to 90%. debayered and stacked in AS!3. Post process for planets was simple - Lucy Richardson deconvolution followed by 100% micro-contrast in Astra Image. See here for what the worst of the raw video was like. I think the 'secret' is to capture data as if the conditions were perfect and not accept poor focus etc. just because the seeing is poor: