AbsolutelyN

Not sure about this one but I had a go at making it starless.

I used my Sesto Senso on the stock focusser on my 200PDS and had problems with slippage. As mentioned it's slipping in the shaft. It could not take my 1600mm pro and filterwheel but I've heard other people's will take the weight without slippage. I switched it to a baader diamond steeltrack which is totally rock solid and solved all the issues.

Brilliant images, absolutely love the subtle processing

Thanks, first time processing dust, took best part of a day to figure out how to make it show up well

Thanks Richard, much appreciated.

Inspired by AlexBB's stunning recent Iris Nebula image I thought I'd have first attempt at this one too given the brief two days of relative clear skies at new moon between the otherwise constant rain. This is approx 15 hours over two nights (bortle 5), mostly luminence with about 90 mins each for RGB. 2 min exposures at unity gain with the 1600MM & Esprit 80. Interesting figuring out how to tease out the background dust, much still to learn, hope to add more for higher image quality in the future.

Outstanding and inspirational!

Just the standard 7nm ZWO narrowband filters - newer version. https://www.firstlightoptics.com/zwo-filters/zwo-125-ha-sii-oiii-7nm-narrowband-filter-set.html

I only managed a couple more hours, probably not enough to make much difference yet, now the British weather has now turned for the worse

Brilliant, your colour mixing is really inspiring. Do you find the longer exposures with the ZWO1600 more effective? I@ve never gone longer than 10 mins, can I ask what gain? Thanks

Love it, great work!

That's an excellent first attempt for M42

Updated with alt processing - thanks for the idea Göran

Thanks Göran - that's a really great idea, love the image and colour palatte. I'll have a play with that combination. Originally I wanted to do HARGB but went with HaSiiOiii as the moon was still so prominent.

Might add more data to this tonight, approx 15 hours of HA, O3 & S2 with Esprit 80. ZWO1600MM, 200 gain Alt processing as kindly suggested by gorann - Red: 100% Ha. Green: 50%Ha+50%Oiii. Blue: 100%Oiii. Any preferences?

Thanks for the adapter link, not seen that one before. Have used the ZWO/EOS adaptor but I could not get a flat field with my 100-400ii. Does it give a nice flat field or is it fiddly to get spacing right?

Full res here -https://www.astrobin.com/full/e2ifzm/B/?real=&mod=

Updated processing

Gain was 200 and offset 50. I've not properly compared the stacked 5 mins to stacked 10 mins to know if 10 mins is worth it or not yet.

Thanks. Had guiding issues at first, then went to 10mins last night after fixing that and also after capturing 10 min darks on cloudy night at weekend. Mostly just to experiment though.

I've only got the 80 a couple of month ago. FOV is similar but quite a bit wider - completely depends what you want to take images of and if you want to title images or not. I can't say I've noticed much difference in sharpness or colour correction, both excellent. I wish the 80 had tube rings, had to get a dovetail for the 80 to get it to balance but not a major issue. NGC7000 with 100 & 1600mm https://www.astrobin.com/404588/?nc=user NGC7000 with 80 & 1600mm https://www.astrobin.com/413027/?nc=user Full res with 80/1600mm for star shapes at edge https://www.astrobin.com/full/e2ifzm/0/?real=&mod=

I also have two Esprits, the 80 and 100. Both with flatteners, optics are superb. I use with ZWO 1600MM, 80 has smaller image circle than the 100 but stars are round right to the edge of frame on 1600mm. With a full frame DSLR I suspect the 80 will struggle at edges.

First attempt at the Elephant's Trunk Nebula, approx 18 hours with Esprit 80 and 1600mm taken under almost full moon over 3 nights. Any feedback for improvements much appreciated. Updated processing Original

Stunning image. Can I ask how you sync the dithering etc with 3 cameras on same mount?

It certainly works. I use a Lee lens cloth doubled over and it grips the tube really well.