fwm891

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....

NGC6888 in Cygnus. Shot this evening before cloud called a stop to proceedings. Subs: 9x 180seconds + 4x300seconds RASA + plus IDAS NB-1 filter iOptron CEM60 guided with 9x50mm finder/guider. Capture: SG Pro Processing: To Integration - APP, then PI for colour and resizing. Francis

I've knocked-up a new filter tray from a block of Delrin. Photos show (I hope) the differences between the original and the Delrin tray. Straight off the machine so needs some cleaning up. I still have to cut the 48mm thread for the filters and fit a suitable ejector pin and pull handle. As yet I have no collimation problem straight out of the box. Because the RASA's corrector lens assembly is fixed it doesn't (hasn't) needed collimation. Hyperstar is a different matter as from what I've read is an absolute pain to collimate when it's added and when removed to use the original secondary. I have an Astrozap metal dew shield for my Edge HD 8 which fits the RASA 8, this has it's own dust cap...

Caution: Celstron RASA 8 and Baader UFC filter changer problems. I’ve just purchased a Celestron RASA 8 from First Light Optics (FLO) which is great, no problems with the RASA 8. My problems came when I wanted to fit a filter changer to the RASA 8 to take advantage of the new (ish) multi narrow band filters available for OSC cameras, specifically in my case an ASI 294MC Pro. I bought a Baader Universal Filter Changer (UFC) from a fellow StarGazersLounge (SGL) member. The UFC was in pristine condition and from looking at Baader’s specification sheet showing all the adapter plates for the UFC’s base (#24591110) I could initially see no problem in finding the right front and back plates to suit. Wrong. The problem for RASA 8 users is the shorter back focal distance 25mm from the front of the RASA 8, T threaded mounting plate (29mm from the front of the central lens assembly mounting). For me to achieve this spacing I had to mount the UFC backwards onto the RASA’s T threaded mounting plate (Baader part number #2459126) would have been fine and kept the UFC facing the right way IF there had been a female mounting plate for the ASI 294MC Pro for the other side. The UFC came with a #2459130 female mounting plate in to which the 294MC fitted. I now had to fit the UFC to the RASA. I’ve ended up machining a new mounting plate for the UFC as there are no female T threaded plates. This has allowed me to attain the 25mm spacing required but it’s left me with having to insert filters with the wrong face to the sky (RASA side). I emailed Baader (AKA-David Hinds) to ask if there were other mounting plates or a modified filter drawer so filters could be inserted correctly – no, was the basic reply. So I had to think about how to get round the problem or reversed filters. Solution (for me) has been to make a modified filter drawer so filters can be inserted the correct way round. Currently in a mock-up state (which fits the UFC base unit) I’m awaiting materials to make the final thing. The photos show the original Baader UFC with the wood mock-up. Differences should be evident but what I’ve basically done is to move the filter mounting plate from one side of the filter drawer to the other. Final photo shows the plate I've made to attach the UFC to the RASA male T threaded mounting. F Milsom 2nd November 2019.

An explosive looking flame sending hot lava down past a spectator.... IC434 10x 120s, RASA8 f2, IDAS NB-1

Portrayed horizontal for those who like it laying down. Details: Camera: ASI 294MC Pro cooled to -20°C, gain 122, offset 30. Subs: Four panels each 4x 120s. Processing: APP (cosmetic correction and stacking) panels saved as tiff. Photoshop manual joining of the panels and tidying the joins, PI for colour work, back to PS to tidy up and save to jpg for display. Mount iOptron CEM60 Standard on Tri-pier Scope Celestron RASA 8 with IDAS NB-1 filter.