fwm891

I’ve had an OO VX12 OTA mounted on an iOptron CEM 60 for photography use with a coma corrector. It’s 1/10 wave optics were superb but the scope was just too big even at f4 for me so I ended up selling it. I then got a VX10 with 1/10 wave optics again superb at f4.8 so the same 1200mm fl as the VX12. Sadly at 73 I’m now having to sell the VX10 because of problems getting it on and off the mount when I want to use my RASA.

Had a 'few' (sadly few being the operative word here) nights now with the HEM 27/RASA/ASIAIR+/ASI585MC combination. (no counterweight used). I run everything off two small Celestron LifePO4 Batteries.

I've used an 8x 50mm TS guide scope with an ASI120MM guide camera mounted on the RASA's top rail for all guiding and not had any problems with finding enough suitable guide stars. I've fitted the guide scope, ASIAIR+ onto a small losmandy saddle. This I can slide up/down the RASA's top rail to fine tune the dec balance when I swap between the 585MC and the 2600MC Duo though with the Duo I guide with it's second sensor.

Guide exposures: I'm finding as most seem to find that the shorter exposure times yeald the best guide graphs and ½ sec to 1 sec being best. That via the 8x 50 guide scope is quite easy and when using a UV/IR cut filter with the Duo. Guiding at <0.5" on a good night is achieveable, circa 0.6" on an average night and around 0.8" with pooer seeing or longer exposure lengths.

Narrowband filters with the Duo (6nm Askar Ha/OIII is my narrowest at present) require 1.5 - 2 sec guide exposures but the guiding doesn't seem to stray much beyond the 0.8-1.0" with total errors showing in the range of 1.25" - 1.46". There are night when things don't go quite so well and others where things are slightly tighter which as this is a grab-n-go kit rather than a permenent set-up.

It replaces the AZ-GTi (with EQ mod) I previously had as a grab-n-go so: a) the GTi would never have carried the RASA 8. b) guiding is better given that the focal lengths used are similar.

For me the pluses:

Carries more load (bigger instruments) Currently using either:  an Altair Ascent 80 f6 Triple with x1 or x0.8 reduce/flatteners or a Celestron 8 inch RASA future: Askar 120APO

Uses the same surveyors tripod so no additional expense on supporting the mount.

Easy to PA via the ASIAIR+

GoTo's are accurate and require little extra time centering

Minuses:

Black mount makes set-up more awkward in total darkness

Azimuth adjustment knobs are small (or my finger are too big) especially if cold.

Heavier than the AZ-GTi (I do keep it on the tripod so not a major negative)

WiFi connection via handset - doesn't really worry me as when in use the handset just lays on the tripods equipment tray.

Operation:

Setting up I've found that I don't fully tighten the altitude or azimuth locking bolts but leave them 'snug'. Tight enough to take out any wobble but loose enough that adjustments can be made to the alt/az axles when doing a PA. I've not found any slackening of the bolts/machine screws during an evening. In fact the last few sessions I've not even checked the 'snugness' of the locking bolts (until just now!) and they're fine.

I've not set the slew rate to 'max' keeping it one notch down. I've not had any problems with the slews from the Home position or when it does a flip. I'd just like to keep the RASA in one piece so a few extra seconds  is worth it.

Happy with my HEM 27.

Link missing?

Managed to fit my Nikon 800E to the Askar 120 APO with its 0.8x reducer also fitted. Shot a number of subjects but I've just picked one 90 second sub from a set of M45 to process this morning.

It was apparent last night when imaging with the 800E that the throat/lens mounting flange was acting to mask the extremities all round especially the corners. Stars are still visible in these areas so perhaps I should shoot some flats and try to reduce the shadowing caused by the cameras lens mounting.

No problems with smaller APS-C formats.

Processing in PI, noise reduction only.

NGC2264 image added (6x 90 second subs) processed as above

Just give him the mug now - magic shot Goran

Hello and welcome etc. Theres the PAS astronomy show on the 23rd March (most vendors) will be giving discounts on kit and lots of kit to see AND HANDLE makes a big difference if you can compare things side by side...

20 hours ago, Elp said:

How are you finding the scope?

@Elp I'm loving it. Images are clean right across the frame with good contrast (APS-C, ASI 2600MC-Duo) which I guess as it's supposed to cover full frame sensors should be expected, but I don't have a dedicated astro full frame camera. I have a Nikon 800E which I'm testing with NINA on my desk top to make sure things sync OK. I'm looking at getting a second 120 to make up a dual rig in the obsy. I've been playing with  FoV simulators not just for subjects but to get a better idea of what cameras I can put on each and how I can get almost matching FoV's with the different reducer/flatteners mated with which camera. ie the 1x flattener (840mm fl with the full frame will almost match the 0.8x reducer 672mm fl with the APS-C) or the Duo and the 585MC with the 1x and 0.8x respectively.

Processing wise I'm using PI but I've found I haven't needed to use BlurXTerminator for star reduction/halo control. None of the images above have used it. All my testing with it has been done at near full moon so I'm really hoping that weather is kind so I can see what it will give with darker sky backgrounds. Quite pleased with the above given the 97% illuminated moon, M42 and M81/82 images were shot with a UV/IR cut filter so no real attempt to reduce the sky background at the time.

I've had an Altair 115 Wave Series previously which I've always regreted selling but going back through some of the older images it wasn't as contrasty. Whether that's tech moving on I don't know but the images don't have the same detail?

Superb image. To me a touch magenta overall ? Please delete my attempt.

First longish clear night for sometime. Bright moon (16.5 days old 97% illuminated) but new scope to try out so solder on...

Scope Askar 120 with 0.8x reducer used for all images, coupled with an ASI2600MC Duo Gain 101 Offset 25.

Had my first go for ages at M42. Series of subs: 25x 60s, 20x 25s, 15x 10s and 15x 5 seconds. These were first registered and individual stacks made in PI, saved as tiff's and then the stacks were brought together in Photoshop (fun!) then back into PI for some tidying up and resizing. I used an Astronomic L2 UV/IR Cut filter for the M42 images.

NGC 281. Managed to catch this in a gap between mine and a neightbours house lowish in the NW.  15x 240 second subs using an Askar Ha/OIII 6nm NB filter. All processing in PI.

M81 / M82 Duo. High overhead again to get away from the worst of the moons glare in the southeast.  10x 240 second subs. An Astronomic L2 UV/IR cut filter was used. All processing in PI.

I have used some of the 'RC' processes within PI namely: StarExterminator to separate the stars and backgrounds so I can process them independently. Also the NoiseExterminator to reduce the noise levels after processing some steps. I've not used the BlurExteminator to reduce the star sizes and halos as I'm still getting used to what the scope/reducer will give me without software interferance.

M42 and NGC281 are uncropped APS-C frames, M81/M82 has been cropped for framing.

I don't think it matters about posting but where people don't 'login' for an extended period them they should expect to be removed. I belong to other forums where that is the case. 18 months for one and I think 2 or 3 years for another.

Solved folks

Just updated ASCOM and plugged the camera in, fired up NINA and it's now cooled down from the camera selection box.

It also seems theres a new driver from ASI cameras from the ZWO site as well. I'll install that later.

Many thanks for your input all.

Francis

@Nigella Bryant @Veej

The camera is connected directly to the lappy. It's an ASI 2600MC Duo.

I'm doing everything you're saying connecting via the camera selection box, setting the required sensor temp, and starting cooling...

But nothing happens until after I've finished framing, slew/center, calibrate guiding, go to the sequence screen and set-up exposures etc, press the start arrow which then triggers my delay and AF, then the cooling starts showing: cooling 0% which increases to 100%...

Which like this morning going  out at 4 it was 4.35 before the first sub started (clouds rolled in 10 mins later) so loosing all that time waiting for the sensor to cool just got a bit frustrating today.

A mono version would be great too

I’m using NINA and entering my equipment profile, confirm the camera temperature needed and switch on the cooling. Connect all other equipment and proceed to select a target, slew to it and start a sequence.

It’s only at this point that camera cooling kicks in. Is there a way to start cooling earlier so by the time the scope has found, plate solved, centred, focused… the object the sensor is at or near temperature and ready to go?

 I’m only going down to minus 10 C so not taking a great deal of time but if I push the camera down to -25C it will take a considerable time.

8 minutes ago, Priesters said:

Very nice. Any filters involved in that capture?  Picked up an Askar 120 myself a few weeks ago but it has yet to get first light 🙄

Thanks. Yes an Askar (D1?) HaOIII 6nm NB filter. Just added to the list - thanks.

When the moon's that near full and that close to my object I normally just go back indoors for more coffee. But lately I've had so little time under the sky I just went for it. So here's my effort from last night (22-02-2024) I wanted 20 x 240s subs that was my aim but had to settle for 9 due to clouds.

Askar 120 APO with 0.8x reducer. Asi2600MC Duo, (gain 101 / Offset 25), Askar (D!?) HaOIII 6nm NB filter, mount iOptron CEM60, Capture S/Ware NINA, Images processed with PI.

Hope you like.

Not into solar stuff but I do like to look at it's images (and these are great)

Many thanks all job done. Need to rest it now. I used braid and flux to desolder. That and a bit of wiggling…

👍

2 hours ago, Tomatobro said:

You will need a "solder sucker" …  I will see if a YouTube vid is available and if so put the link here  search using a solder pump to desolder

Found a few vids thanks…

On 20/01/2024 at 19:05, w4m0330 said:

Great work!

I am curious how the guiding works? Could rasa 8 sufficiently illuminate the small chip in the 2600mc DUO? More interesting to hear how dual band narrowband, e.g., IDAS NBZ, works for guiding?

Thanks.

Yes the Duo guides with NB filters like the NBZ (which I have) also with a 6nm Askar HaOIII (D1). I have had to increase guide exposures from 2 sec to 2.5/3 sec depending on star fields. The RASA 8. will illuminate the second chip and at f2 guide stars are brighter.

I have a CEM 60 which has a small board with 4 USB 2.0 sockets (in 2 pairs) on it and 1 of the sockets has basically fallen apart. Before I spend what seems mega bucks on buying a full replacement board does anyone know if its possible to just remove/rep[lace the failed USB sockets?

If so where would one find them (not into electronics as you might have guessed)

Cheers

I'm using an HEM27 (no encoders) with a RASA 8 mounted no counterweights, tripod mounted (braced surveyors tripod) camera asi2600MC Duo so guiding at 400mm subs are usually < 0.8" on good nights circa 0.5" using 1 - 1.5 second guide exposures with no filters. Narrow band filters require longer guide subs of 2 - 2.5 seconds but still around 0.8" guiding. I do balance the dec carefully and avoid using a dew shield if possible. I keep the tripod legs as low as possible and locked out once levelled.

On 10/02/2024 at 21:11, Ags said:

Whew! Adjusting the mount to 52 degrees latitude was more fiddle than expected. I didn’t expect the doodad to disassemble into 5 pieces, and the tiny washers hiding behind the whatsit took me by surprise. There was a dark moment when I thought it wasn’t going back together!

Same with HEM27...

Superb. Simply Superb!

38 minutes ago, Icesheet said:

Thanks for the opinion. Seems like yours is like most. If you can work with the quirks and deficiencies of the RASA it seems most are happy. I’m maybe just a bit too apprehensive of leaving my refractor comfort zone. 

https://www.firstlightoptics.com/starizona/starizona-rasa-8-filter-holder-for-larger-sensors.html

FLO it seems do a filter holder for the RASA that fits the 2600MC....

At present I'm happy having the two set-ups. this is my second RASA 8, I regreted selling the first the second it went out the door.