tomato

Here are three from me: Managing to image (I think) from my back garden, the plasma jet emanating from the pulsar 3C 273 . It is probably the roughest image I have ever taken but the scale of what I was looking at just blew me away. Acquiring a second hand 16” Dobsonian for visual astronomy. I’ve only used it a couple of times so far but I have experienced some “Oh Wow!” moments that the visual astronomers write about on here. Coming second in the SGL PN and SNR imaging competition. For the first time I felt I might actually be making proper use of all the time and money I have sunk into AP.

Interesting post, if it happened to me I think I would always be thinking back to what my sky could be… So how do we get everybody within a 20 mile radius to turn off every light after midnight?😏

Superb Spaghetti, total respect for achieving all those hours of integration, even as a collaboration. Great to see images of this quality being taken from the grey UK.👍

+1 on the expectations of individual subs. 2 minute exposures on the 268c are very uninspiring, especially when I compare them to a 5 min mono sub from the KAF 8300 CCD. It’s the stacked image that counts.

I must agree with @vlaiv on at least one point, no amount of clever software will compensate for an under engineered mount, especially one carrying it's maximum payload. I think someone of Scottish ancestry said "you canna change the laws of Physics"? I had a quick look at some threads discussing entry level mounts for AP and my general conclusion is that the SGL community having given reasonably well balanced advice. Almost all of the "HEQ5 is the minimum mount you should get posts" have qualified the statements with why the choice of target, the combination of equipment or expectation of the results obtained, would require the mount, and the threads are sprinkled with numerous posts extolling the virtues of the EQ3 mount or similar, but again highlighting it's limitations, the additional work involved in optimising it's performance and what kind of AP it is best suited for. I think with the diverse membership of a forum like SGL covering the full range of experience, knowledge and budget, you are bound to get a wide range of opinions but I don't think any of those expressed have been deliberately dismissive of folks wanting to try out AP on a limited budget. Quite a few mention buying the "Making Every Photon Count" book, still the best piece of advice IMHO for anyone starting out on AP. I have just read through the choice of mount section and although inevitably the technology has moved on a bit, it's still sound advice in my view.

Yes Dave, I agree, a definite improvement over V1. There are now two very good user friendly star removal tools available, which keep on getting better. It's a win-win for us imagers.

I have had a go using Starnet V2 in PI to remove the stars for processing the galaxy. I think the dark halos are less pronounced on this one? I might hold on to my £44 for the StarXterminator license for a while longer...

Thanks Colm. I used StarXTerminator to remove the stars and processed the starless image before putting them back in. I think the star removal process makes a contribution to the halos but I’ve processed other images where the end result has much less noticeable halos so my processing has a lot to do with them.

A great Spaghetti Nebula! I blitzed the stars on my 4 panel mosaic but you have enough signal to leave them in and produce a wonderfully balanced result.👍

Thanks, the 268c was in DSO photographic mode, 120 sec exposures using an IR/UV cut filter. Each panel was 40 minutes of integration.

Hi Dave, I can’t give you a direct comparison of a OSC CCD vs CMOS as I moved to mono CCD imaging after a short time with a little Atik 314 OSC. However here is the closest I can get which is a 6 panel M 31, capturing Lum with a KAF 8300 sensor and RGB with a QHY 268c, both on an Esprit 150 dual rig so the same scope and imaging conditions. To be fair, the CCD was using the Esprit 0.77 focal reducer while the CMOS had the field flattener so the CCD was imaging at 1.33 arc sec per pixel, with the CMOS at 0.714, but the FOVs were very similar. I cut my CMOS imaging teeth over a season imaging with ASI 178 mono sensors before moving to the OSC, but early on my processing skills lacked a lot so I wasn’t doing either sensor justice. The CMOS break through was doing shorter subs, I have never bothered playing around with gain or offset. LUM CCD RGB CMOS

This is a ridiculously short integration on the Monkey Head Nebula, 15 x 2 mins RGB and 9 x 4 mins NBZ with the Esprit 150/IMX 571 rig. Calibrated and stacked in APP, binned 25% in StarTools then processed in PI, creating a pseudo Hubble palette from the RGB channels. It's not surprising with just over an hour's worth of data that the background is quite blotchy. I think I know where the monkey (baboon?) features are supposed to be but they don't appear very prominent to me, needs more data? Thanks for looking

Thanks for your comment. The camera settings are gain 30, offset 30, exposure 120 secs. The cameras are uncooled versions but have been retro fitted with Peltier coolers and a temp control module so that the sensor runs at around 3 deg C.

Yes with CMOS cameras I use darks, flats and flat darks. The darks are essential with the ASI 178s I use for small object imaging as they have a healthy amp glow, and I just stick to the same regime for the IMX 571 cameras.

Galaxy season is just around the corner and while waiting for M101 to clear a large oak tree to my North I thought I would have a go with some old data (Esprit 150/ASI 178, binned 2x2) using some of my newly discovered processing techniques, namely the EZ suite and star removal tools in PI. Still struggling with the dark halos around the bright stars. This is around 9 hrs of L and 3.4 hrs each of RGB.

True, although I struggle with making dithering work on a dual rig, even with NINA. In APP I know Mabula extolled the virtues of creating a Bad Pixel Map so I have stuck to that mantra.

Are there not hot and cold pixels on these sensors, they don’t normally put premium grade chips in commercial astro cameras? If so don’t you need the calibration frames to produce a bad pixel map?

Sorry for the late reply, yes that’s the dew heater I used. I have run the camera for extended periods at -15 deg C set point in 95% humidity, ambient temp 1-2 deg C and no repeat of the fogging issue.

It is fortunate for me given the UK weather, that I derive a great deal of enjoyment from researching equipment, choosing components and then assembling and optimising their performance to produce images which sometimes at least for me, justify the investment in time and money. Everytime we get a run of poor weather (so that’s often) I reconsider the remote imaging option, but to date I have not been persuaded.

Thanks for posting. I purchased a used 16” flextube last year which I transport from the garage to the back garden on a custom built 4 wheel trolley. I do have to extend the tubes and collimate each time but this is straightforward with a Hotech laser. l’ll confess it is bit of a beast and given that I’m imaging first and foremost I only feel it’s worthwhile setting up if l have the prospect of a cloudless, clear, moonless night. Needless to say, It’s never going to get worn out through over use, but no regrets on acquiring a decent light bucket for visual use.

Have you thought about entering it in the SGL animation competition?

Great capture and presentation, I’m really impressed how stable your background and stars are in the animation.👍

To answer your post question, yes it clearly is wrong, you can do entry level AP without an Astro mount of any kind. I think that folks who have gone deep (in every sense of the word) into AP give the HEQ5 advice simply to avoid the regret spend of buying a lower spec mount then trying to do long exposure imaging with it using a heavy scope and camera. Not everyone who ventures into AP gets lured down the rabbit hole of ever more extensive (and expensive) kit in the quest for ever better images, and there is no doubt excellent results can be obtained today with modest equipment. With the advent of sensitive low read noise CMOS cameras the traditional approach to AP is changing, you might be better investing in a decent PC to process those hundreds of 5 second unguided subs the CMOS camera can generate, rather than a heavy duty mount. The irony is the appeal of the CMOS cameras is making used CCD cameras more affordable, but they, in my view, do need a good mount to get the most out of them.

Would you use finder scopes on a set up like that? I’m guessing they are used for outreach or teaching purposes.

What I like is that it appears to be installed in somebody’s urban back garden. I must show the photo to Mrs Tomato as part of my campaign to acquire a Planewave 17” CDK.😉