fwm891

Out with the CEM25P again last night. I mounted the William Optics ZS73 again + a Baader 7nm H-alpha filter and the mono Nikon d5100. NGC1499 (California nebula) was one of the targets. This image is 15x 300s subs, processed in APP and PS-CS3.

This is a partial process - only the 60 second subs from each panel have been merged to see if the whole thing worked. Shot last night it comprises four horizontal panels, stacked vertically then rotated for posting. Each panel has 3x 60s subs, processed in APP and PS-CS3. Details: Scope: RASA 8 Mount CEM60 Standard on tri-pier Camera: ASI294MC Pro (gain 122 - offset 30) Guiding: PHD2 via TS 80mm guide scope and asi120MM-S camera. Capture: SG-Pro Now to process the other subs... Hope you like All subs: Each panel has: 4x 30 s, 4x 60s, 5x180s and 5x 240s. Processing as above, no calibration frames taken for this image yet. This is a lights only mosaic.

With my iEQ45 Pro when telling it to go to zero I loosened both clutches, let the mount do it's thing then set the clutches with weights down scope pointing north...

I don't have an EC version of the CEM60 but have a similar set-up. You've run a PA drift align and got fairly flat traces for both axii so that should be fine. The CEM's are dead easy to balance so I presume you've balanced first the dec then RA axles - ruling out balance problems The encoders are just providing a constant drive rate (PPEC) they're not sensing against the stars so your guide pulses should be OK. However your problems do look RA oriented. I have a Williams 73 ZS with finder guider, my calibration steps are much higher circa 2500 and calibration steps are usually 14/15 west, 6 east and 8/10 for north/south steps. At 500 it would take probably 30-40 steps to reach the +25 threshold. Is the focal length of your guider set correctly? Hysterysis I set to 30, guiding 1 rarely use anything other than 2 seconds, minimum mo 0.15 (dec & RA) aggression 70% RA 30% dec. To me your Calibration steps are too short (Brain / Guiding tab) and your minmo set to zero doesn't allow the mount to settle and it's always chasing itself. Cables: are they dragging or fouling anything...

@Danjc Great thread. I have the same PPB and it works a treat. I run 2 dew bands, camera, mount and focuser. While my USB's plug into the back of my CEM60. Like you I ended up getting Lindy USB cables to make sure the USB's didn't cause issues. I find the 4 power out puts, 2 dew bands and the environmental indicator do all I need. Thanks.

I've only really used this mount once seriously but I have to say I've been surprised: it's smooth, it's quiet, it tracks well unguided (though only taken to 60s so far), guides well too (5 min subs). Guiding here used a 9x50mm finder and asi120MM-S camera. I chose a couple of well know targets and shot them using a William Optics ZS 73 + (1x) flat73a + Nikon D5100 mounted on the CEM25P. Each image is built from 5x 300s subs, processed in PI. Capture via APT. No filters used. I purchased the mount and light weight tripod from FLO and set the tripod, mount and OTA assembly on our patio area. Comprising stone slabs. I have a motor cycle 12 VDC power source which I've hung from the equipment tray. USB cables from the guide camera, 2 leads from the Nikon and the mount all fed into a non powered USB hub at the mount with a single USB extension cable back to the laptop in the conservatory. iOptron's Commander software was installed, APT used for captures, Bahtinov mask (built into the ZS 73 hood) used for manual focusing all images saved to camera card (card slot on my old laptop U/S). Images imported into PI for alignment, stacking and levels adjustment, resizing and saved as jpg files. My D5100 is a mono modified DSLR so some cropping has been done to remove the ragged edges around the chip/sensor. See uncropped single sub. Setting up. I started by assembling the head onto the tripod minus scope and counterweight but including the motor cycle battery. Getting the head polar aligned using a phone app to indicate the position of Polaris. I then added the OTA and counterweight and rechecked the PA via the polar scope (minor adjustment required) I find this unloaded/loaded approach to PA easier than making bigger adjustments with a loaded tripod. Connected the four USB leads to a hub located on the equipment tray/leg spreader at the mount and USB extension to a Win 7 laptop. Fired up Commander, PHD2 and APT. APT's plate solve used to centre objects and sync when centred. As this was a first real outing with the CEM25P I did a two star alignment/sync to on a couple of widely spaced stars before heading foe Andromeda and M45. I set-up a plan in APT to take 5x 300s subs. These were processed in PI only. Will follow this up later when weather permits.

Pixel scale 2.39 sec/p

@tooth_dr Thanks. Single frame, slight crop due to meridian flip not fully registering. Not full res as files size circa 60Mb but posted as png to retain better bit depth.

First clear skies last night for over a month. This group of objects I've tried before but never had a reasonable run with no moon around. Although fog put an end to captures around 10 ish I think the data I did get was worth it. Details: Subs: 9x 180s, 11x300s and 10x480s Camera: ASI294MC Pro (gain 122 offset 30) OTA: RASA 8 Mount: iOptron CEM60 Standard - guided with TS80 guide-scope and ASI120MM-S Capture: SG Pro Process: PI and tweaks in PS-CS3

After looking at a video thread re adapting a Nikon Z body to take filters (https://stargazerslounge.com/topic/344270-nikon-z-with-astro-filters/) it made me think of my Lumix GX80 which has interchangeable lenses and I have an adapter to take non 4/3rd's Nikon lenses on the GX80... Turns out the internal thread was 46mm x 0.75mm so not an off-the-shelf adapter size. So I set about making an adapter this morning. First photo shows the adapter with a 1.25" red filter in place, photo2 shows the filter inside the Nikon lens adapter mounted on the GX80. photos 3 and 4 show the Lumix with a 70-200mm Nikon lens attached. The red image is the lens/camera combo pointed to the overcast sky showing almost no vignetting at full aperture (f2.8). Probably use this with a UV/IR cut filter on a scope - currently raining so no chance to test the mods. TBC...

Great description and video. Immediately made me grab my Panasonic Lumix (4/3rds chip) GX80. This has interchangeable lenses and I have a Nikon to Lumix 4/3rds adapter which at a quick glance looks like I too can insert 1.25" filters into... One of the exposed threads inside the adapter eyeba;lls at about 42mm - if so I can get a 42mm to 1.25" filter stepdown male to female ring. 🙏

I like that Brian - Background a touch dark (for me) but plenty of detail in M1. 👍

@JOC Yes. That's the Horse Head nebula. Sits just below the lefthand star (Alnitak) in Orion's belt

@daz Does the SA drive in reverse direction to correct backlash or is it waiting for the sky to 'catch-up'?

@PhotoGav Couldn't agree more. Collared Steve for other things early Friday but got talking about the various projects in the pipeline. Superb. Way beyond a 'retailer'. My bank manager might disagree...

Thanks ALL

Feeling a [removed word] but how do I link to someone's post so they know I've responded to their question? I've tried putting the '@' immediately before a name but it never highlights... Cheers

@freiform Yes. You'll get the odd noise but compared to the SW NEQ6 Pro I had my CEM60 whispers. Beginning and end of slews I get a short grunt as the motors wind up/down. I found that doing nudges from the handset in the 16 to 128? range was the noisiest.

I went from NEQ6 Pro (belt modified) to an iOptron EQ45 Pro then to an iOptron CEM60. While I had problems with noise on the CEM60 FLO replaced it without a quibble and the replacement is superb. I'm considering a CEM25P (non EC) as a portable set-up which I want to check out at the IAS.

Great image Rodd. Processing nightmare I guess.

Superb image, one of the best I've seen posted lately, and very well processed too 👍

Very quickly gathered image of the Cocoon (NGC5146) from last night. Subs: 2x 120s + 3x 300s

Quick session earlier this evening before rain came.... Subs: 10x 180s, 10x 300s RASA 8 on CEM60 Capture: SG Pro Processing: APP, PI and PS. Moon 90+% illuminated

Annotated image added

I forgot to flip the image so it's now been updated. Something else to get used to with the rasa....