geeklee

Wow. That's very poor. My own experience (3.5nm Ha, 4nm OIII and 4nm SII - normal speed) has been mixed with the equipment I've tested on. My first set had black hairline paint lines coming from the edges (these are 31mm) on OIII and the edges on one other wasn't great. The replacement set were much better. I have some halos on brighter stars. In individual subs they are hard to see. Here's Eta Gem (mag 3.3) with an STF in PI (strong) - 4h Ha, 3h OIII and 2.5h SII Example images using these with my RedCat 51 and 294MM https://www.astrobin.com/swc0q9/ & https://www.astrobin.com/ke9eqx/ My main takeaway from using these is that very narrow band filters do make a big difference and I've been pleased with that side of the performance.

This is a great addition to a typical narrowband target. Very nice image and well worth the integration. Lovely starfield.

Good point, I hadn't noticed until I caught your reply on my phone and could see it on the small screen. Looking on my monitor I can see it now. Nice spot 👍 If I get a proper chance to use the camera on my Samyang I'll check the flats with the Astronomik 1.25" MaxFR 6nm filters.

Good depth and colour Adrian. A real sense of rolling, churning nebulosity. It's great to mix and match data that may otherwise have not been used.

There is something about that OIII that, like you say, feels like the centre is slightly brighter but overall it looks uniform. I'm definitely going to keep an eye on my OIII. My narrowband filters are 31mm. Out of interest, what size are yours? Here are my Ha, OIII and SII master flats: Thanks for sharing!

That's excellent Dave. As mentioned above, the OIII getting fainter and fainter plus that elusive and almost "not there" Ha even further out (and in the bottom left of the nebula) shows superb processing.

Tablet with sheets of paper. My OIII looks totally different to my Ha and SII, but still not a typical uniform flat. I've double checked some calibrated stacks and they look flat. I've stretched them to absurd levels and can't see a pattern that matches the flat. I'll keep an eye on the OIII though - thanks for the heads up. Although not worth much saying this, my flats are Ha (15.5s), OIII (12.5s), SII (22s). These are with the Baader Ultra Narrowband filters. Wouldn't calibrate a light or would look all wrong... or both?

I can't say my narrowband flats look typical but it seems a known "feature" of the 294MM and calibrates OK. If you'd like any example subs / flats for the 294MM just drop me a PM.

Thanks Mick. I'm always surprised by the detail the RedCat's 250mm can show even with the bigger 4.6um pixels in bin2 mode of the 294MM (just like the 460EX). Loads of Ha helped and as mentioned, the Flaming star benefitted from that SII. EDIT: throwing out the bad subs (high FWHM, haze etc) helped too I'm sure.

I've been chipping away at this since mid December 2021 so not too long but long enough for frustration to creep in waiting to get more decent OIII and SII! After leaving around 4h of mainly Ha (but also a little OIII and SII) on the cutting room floor I was left with ~10h Ha, 3h OIII and 2.5hr SII. The SII was fairly strong and was crucial to add structure to the Flaming star region and also the stronger background nebulosity. The palette is a trade off against losing the familiar, strong reflection area in the Flaming star. I'm OK with that for now 🙂 I was surprised by the detail in the spider and fly (top left) and there's a nice "double antennae" piece of nebulosity just to the right, and up from these two. I tried to focus on bringing as much of faint nebulosity out as possible, with some structure and looking natural... I got close I hope. Please click through and zoom in, as always I try and process these for 1:1 viewing. This was shot with the Redcat 51 and 294MM Pro. Captured with Voyager, pre-processed in APP and processed in PixInsight. Thanks for looking. A few more technical details (dates captured, filters etc can be found on my Astrobin - link in sig below)

Very nice Adrian. With the right integration, the RedCat is still fast enough to get a detailed and deep image on the 183MM.

Great capture with a lot of challenges! Excellent perseverance seeing this through 24 hours.

I'm typically imaging with a smaller sensor Andy so not sure what would optimise an APS-C size version. On my StellaLyra RC6, I have the Baader Diamond Steeltrack focuser upgrade and have a reducer too (not used this yet)

Hi Martin. Although not with the NBZ, I definitely see the R & GB focus difference in the Samyang 135mm (mine and others). My Green, Blue (and of course OIII) focus at a similar point but Red (and Ha) is totally different. While waiting for my gear to warm up the other night, I finally did a test rotating through R, G, B, OIII and HA filters with a bahtinov mask. I was focused for OIII. G, B and OIII produced a perfect pattern and Red (and Ha) as expected were way off. I use my Samyang at ~F2.8. Your Orion image looks great.

Great first light Andy. Very nice star field and plenty of detail in the Bubble. I haven't dusted off my RC6 yet for this year.

A new one for me Mick, thanks for sharing. It must have been quite the experience seeing nothing on a single sub. It's time well spent as you've brought out the colour and detail.

Excellent Image Dave. Really enjoyable at full resolution - as you say, much have been challenging to manage the noise against the dust - great job.

@Mikey0368 Here's a view from Telescopius simulator. 550mm FL, ASI294MC Pro camera size. Camera angle 0deg. Single pane, centred: 3x3 Mosaic: I'm currently imaging with a 135mm lens but a smaller ASI183MM and it just fits.

Fantastic @scotty38 Those halos are frustrating popping up on medium stars as well There seem to be a lot more dual band filters on the market recently for OSC, it might be worth a look around. Mono isn't always a halo-free either!

Thanks both for the feedback! 😊 At the moment, not really Dave. Your continued notes in this thread help a lot (and I still need to spend time with the documentation). It was getting a feel for where to focus the stretch in later iterations. As per my previous messages, I'm still not all there with contrast but getting more comfortable in the tool itself.

My first proper go at stretching three masters - Ha, OIII and SII - using the GHS script with multiple iterations. It controlled Eta and Mu Gem well during the stretch. https://www.astrobin.com/swc0q9/ Thanks again @mike1485 and @Gunshy for their efforts. A useful addition to the toolbox.

Thanks Dave, this was a useful addition to existing commentary. In the video you ask for the SP to be placed just to the right of the histogram peak (for the first stretch) but in an earlier thread here where you ran through the basics you said to put the SP between the start of the histogram and the peak, so to the left (of the histogram peak). Was the video a one off change for that data? Thanks

I've had a CEM26 since the start of November but it appears to be a slight revision as a few things were different to photos / existing mounts. I hope the QC was part of these changes! Mine has been imaging for ~20-25 hours (that can't seem right in UK weather!) and so far it's only needed the gear mesh on DEC tweaked (it was too tight). I think the RA could do with a tweak - I'm still working on this. My current image scale on this rig is ~3.7"PP. Typically it'll be well under 1" RMS with the graph having occasional spikes ~2". It also recovers from RA and DEC dithers OK. My image scale is very forgiving so there's no concerns but with something below this, there might be more to investigate/tweak.

Fantastic set of images @drjolo The molecular clouds in Perseus and the Coma cluster are stand outs for me.

Both fantastic images Adrian, with loads of detail revealed by the Samyang+RedCat combo. Presented this way, it's nice to put patterns aside (NAN and Pelican) and concentrate on other aspects. Within the second image (the first to a lesser extent) that central dark dust area looks stunning against the bold, bright background - covered in genuine fine detail and adding a real depth to the area. Nice crops and information on HH555 too.