CEM25P Standard - Initial thoughts

[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.

 

 

 

Edited November 30, 2019 by fwm891
File swap

[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.

[A40farinagolf]

Hi,

How are you getting on with your CEM25P?

I ask because I have just purchased a 2nd hand one and hopefully it will arrive soon.

Any hints and tips would be gratefully received.

Cheers,

M