tomato

I was getting warnings in APP that the offset was too low when set at 30, I raised it incrementally until they disappeared. What’s the problem with an offset of 255 apart from losing a little bit of dynamic range?

Hi, I use gain 30 offset 255 on both a 268M and 268OSC. With a 6” F7 refractor under a Bortle 5/6 sky I use 2 min subs for LRGB and 3 min subs for NB.

Did the insulation break down and cause a dead short? I’m not a fan of 240v near a rig for all sorts of reasons.

Thanks @wimvb, I will look at the BXT settings, all I did was use a manual PSF value from the image, everything else was set at default. Thanks also for the image link, I was using an image taken with a 400 mm reflector, although there is some filamentary structure, it doesn’t make the distinctive pattern present in my image. Ha is a great idea, especially as the moon is now butting in, big style.

The pinion jumped out of the rack and bent the bolt holding the idler roller, easy to repair. There is now also a routine in the control software that waits for a manual test on the limit switch to demonstrate that the padlock has been removed.

My second hand Pulsar dome came with a padlock on the shutter which I thought was a good idea. Shortly after motorising the shutter with a rack and pinion arrangement and a substantial drive motor I attempted to open it with yes, you guessed it, the padlock still in place. There is now over current protection on the motor.☺️

Having experience of imaging with a RASA8/OSC IMX571 combination, I would say that once you have the camera aligned, imaging with it is reasonably straightforward. It holds focus well, doesn’t need a high cost mount with precise guiding, the corrector plate doesn’t dew up with a camera blowing warm air across it, and deep images can be completed in a single session, so I guess it is no surprise that they are now a popular choice in that budget range. But… they aren’t really meant for small targets, of which there are literally hundreds to go at. The trouble is imaging them is always going to be a challenge from the UK given our weather and poor seeing, but how does the quote go, “We choose to do these things…”

Is it just me or are small targets being posted less frequently these days compared to the deep wider field images? At one time, a lot of imagers aspired to a large aperture RC but now F2 RASAs and the like seem to be more in the spotlight. Anyway, here is another small and somewhat obscure galaxy image, it is Galaxy Season now, after all! This is NGC 4395 in Canes Venatici, a low surface brightness galaxy some 14 million light years away from our own Milky Way. The brighter active regions have their own NGC numbers, 4399, 4400 and 4401 but these were not picked up by PI's annotation script for some reason. Captured with the Esprit150/ASI178 rig as follows: Lum 166 x 2 mins Red 83 x 2 mins Green 85 x 2 mins Blue 68 x 2 mins (Blue the poor relation once again) Total integration 13.4 hrs Calibrated and stacked in APP, LRGB combination in APP, processed in PI with the (for me) obligatory RC suite of AI tools. I deliberately eased off on NoiseXterminator to try and emphasise the structural detail, such as it is. Now is that 'swastika' structure in the spiral arm at 4 o'clock real or an artefact? I've seen something similar on other images but I suspect BXT has joined the dots, but hey, it can only work with what it is given. Thanks for looking.

Brilliant result, one of the best NGC 2903 images I’ve seen.👍🏼

Yes, it’s a problem, and I know I can’t come close to professional results on small galaxies but that won’t stop me trying. There are other challenges for close in imaging e.g. plasma jets, Crab Nebula pulsar etc, so I don’t regard it as an unrewarding exercise. I do enjoy imaging gas and dust with the RASA but galaxies motivate me more. It was @gorann’s M31 first light with his RASA that prompted me to get one, if he had gone straight to Ha and IFN targets I probably would never have bought one!

The RASA is a fine scope but like all of these "Which Scope?" threads, it depends on want you want to see/image. If you want small galaxies like this: Then you need one of these: Oh, and it needs to be located in Atacama...

Very nice, how do you get the 4 big spikes on the bright stars?

FLO must be panicking if they read this thread, they will have visions of a big pile of unsold blue filters sitting in the warehouse.😉

Last night, while waiting for my intended target to rise higher in the sky, I captured 3 hrs of LRGB on NGC 2403, just as well as I was clouded out by 9 pm. It has come out better than I expected given the poor conditions and meagre integration time, so I combined it with some wider field data taken last year to double the integration time. 178 mins on Esprit150/IMX571 OSC and 195 mins LRGB on Esprit 150/ASI178. Thanks for looking.

Apologies, I thought it was one of the default options in the NINA focus menu but perhaps it only appears if it finds something meeting that description connected to the PC. I was using the Hitec Ascom driver which NINA wouldn't recognise, but it must have assigned this 'Generic Hub' label to it, and it works OK.

Which option are you using to try and connect the focuser? I had connection problems with an old version Hitec Focusmaster controlled stepper motor, but it recognised it using the ‘Generic Hub’ option.

I’m surrounded by houses so can’t image below 20 degrees altitude so that is my default cut off. If taking separate RGB subs, I always try and take the blue at the highest elevation. Beyond that I let the stacking software do it’s thing on weighting the subs.

Sorry it is off topic, but it is an interesting difference in spec on the OSC 571 sensor window from the different camera manufacturers: ZWO: IR cut filter QHY: AR window Touptek(Risingcam et al): IR/UV filter or AR window, customer specifies.

That’s interesting, can you specify the ZWO version with just an AR window? How does that work when using the dual band NBZ filter? I thought it would be better just to have an AR window on the camera under those circumstances, hence that is what I specified when purchasing the RisingCam version of the camera. Also, I have assumed that’s what comes with the QHY version, otherwise I have been imaging with two IR/UV filters in my optical train. Olly, have you or Paul taken the clear window out of the RASA, or is it still in place?

Apparently you can only visit the island between March and October so not much good for viewing in the long dark winter nights, but still, it is quite an achievement.

Excellent panorama, deep and detailed and really well stitched together.👍🏼

Nice capture, easy to see how NGC 2356 got its very descriptive name. I would like to have a go at this one if the permacloud ever clears.

A lot will depend on if you intend running unattended sessions. If you are there, you can always approach the focus point from the same direction and hence take care of any backlash that way, but I don't know if you can make that happen automatically from the focus routine, I will need to check if it is possible in NINA. I use the HDR numbers rather than the visual image, with my ageing eyesight the focus can drift quite a bit before I see it show up in the sub image.

Thanks for this, it is definitely on my list for this Spring season. @Paul M, great post, capturing the jet is not easy but it’s possible, to get those few illuminated pixels is quite something.

In NINA and I guess other image capture software, the routine moves to the in focus position to take the final image and so will always need to reverse direction. I always visually check this image although it is rarely a problem. Likewise I never rely on filter/temperature focus offsets, just like with guiding performance, the image is the acid test.