BlueAstra

A motor focuser can hold the focus knob tight and prevent movement if that is the issue, although it could be a temperature effect. Was the scope at high elevation with the weight of the camera pulling it down? Is the camera equipment within the load limit of the scope?

If you are considering a motor focuser have a look at my thread here: I also had a custom spacer made up here for my camera to set it at the correct distance from the field flattener. I got some thin steel washers (later plated by local firm) from ebay to act a fine focus adjustment: http://www.jtechdesign.co.uk/ ESPRIT ADAPTER.PDF Graham

Thanks for the replies. I’ll try again this evening following the guidelines.

Not sure where the correct place to post this is, so please move if required. I have a ZWO 224c camera imaging through a C9.25. If I use SharpCap 3.2 I get the first image (single frame from video), which appears to be very noisy. If I use FireCapture I get the second image which looks much smoother. I'm pretty sure I used the default settings, more or less, with each software package. Can anyone explain what is happening and how I can get a smoother image in SharpCap? Or is it an illusion and just some display artefact which won't affect the final image? FireCapture Jup_002201.txt SharpCap 00_09_11.CameraSettings.txt

I have now managed to attach the Pegasus Motor Focuser to the Esprit 150. With the help of the focuser patent drawing I was able to identify some of the features on the bottom of the focuser: A – Threaded hole for grub screw. Not sure what this is for other than to hold a spare screw for the knob fixing screws. If you screw it right in then it hits the spindle and locks it. B – Access hole for knob locking screws. Rotate the knob until the screw is visible, loosen screw and pull off the knob. C, D – Not sure what these are other than to hold the spindle assembly to the focuser barrel. E – Screws to hold the bearings (12 on patent drawing) which grip the metal plate attached to the barrel. F – Tension screw which controls the pressure of the spindle against the metal plate G – Locking knob (221) which clamps the barrel plate and prevents any movement of the focuser. I wanted to remove the coarse knob to attach the motor focuser. However, it was stuck and would not remove easily. I removed the x10 knob (easy), loosened the tension screw F and withdrew the spindle with the coarse knob attached. I put the spindle in a vice (taking care not to grip the plate contact area) and twisted the knob off. Once off it went on and off quite easily, so something must have been holding it. I then re-inserted it into the focuser, re-attached the x10 knob and re-tensioned screw F. I now had a bare end of the spindle to attach the focuser to. I offered up the motor/L bracket and found the L bracket was too long. It interfered with the locking knob G. I removed some material to avoid the clash. I then set the motor position on the bracket and secured it. I removed two M3 screws at C and used two longer screws with washers to secure the L bracket. A locking cylinder connected the motor to the focuser (a selection is supplied with the motor). I connected the temperature sensor, 12V power and USB cable, and I can now control the focuser through its own app, or via Ascom in other programs. The motor is too stiff to allow manual focus via the knobs. You can get a manual control box but it’s quite expensive. I am currently trying to take out backlash by adjusting F, although there is backlash control in the software. I’m not familiar with focuser construction, but I was surprised that it operates by pressure of a bare metal spindle on a flat metal plate. I thought there would be some friction material between them. It remains to be seen whether it can cope with large camera loads at high declination. If not I may have to upgrade to rack and pinion.

Does anyone know the correct mounting points for a motor focuser on an Esprit 150? Looking at the bottom of the focuser there are four slotted screwheads that seem to be set in concrete. Are these the best place? Also how do you get the focuser knobs off. The x10 knob comes off easily by undoing a screw, but there are no obvious screws for the large knobs. Again they appear to be set in concrete if you pull them. The focuser is a Pegasus cube on an L bracket.

Thanks for the information. No wonder my metric bolts wouldn’t fit.

Can you tell me what size bolt you used to secure the brackets to the top of the mounting rings?

Does anyone know the thread type in the mounting rings supplied with the SW Esprit 150 refractor? There are five holes in a line on the top of each ring, opposite the dovetail.

So you leave the scope attached to the clamp/dovetail assembly and attach the handles to the top of the closed clamp? Thanks for the replies. Sound like the consensus is an EQ6 or similar so I’ll take a look at what’s available second hand.

I managed to pick up an Esprit 150 second hand recently but haven’t got round yet to installing it in my observatory. So in the meantime I wondered about using it for outreach at my local Astro club for visual or EAA. What would you advise as an economical portable mount for this scope?

Thank you for the comments, and any more that may appear. With my current setup (0.43deg/0.76"pix) I have tried 2x2 binning (0.43deg/1.52"pix) and noticed that the image doesn't look quite as sharp as the 1x1 image, and when you zoom in the stars look a bit more 'blocky' (technical term). That's probably subjective and I may be imagining it! So at (0.83deg/1.45"pix) I assumed I would get similar results to my 2x2 efforts, and hence a smaller pixel would beneficial. My mount is a Paramount MX and guides quite well with my SX Lodestar OAG. Graham

I've acquired an Esprit 150 (150mm Aperture, 1050mm Focal Length, F/7). With my current scope I use an SXV-H16 camera (2048x2048, 7.4um KAI4021M) which gives a FOV of 0.43deg and pixel FOV of 0.76". The may be a little over sampled, but I seem to get decent results. With the Esprit the SXV-H16 would give a FOV of 0.83deg and a pixel FOV of 1.45". My feeling is in this case the pixel FOV is a little high and I could do with something with smaller pixels. If so, what would be the recommendation for a reliable mono camera for use with the Esprit in the £0-£1.5k range? The SXV-H16 has been my only camera to date, doesn't seem to need darks, and I have no experience of the newer CMOS cameras.

1.25" Ha Night Sky Filter. This filter is generally used for light pollution suppression during deep sky or lunar mono photography (eg Ha, O3, B&W, see link below). £27 including UK postage. https://www.astroshop.eu/h-alpha-filters/lumicon-h-alpha-filter-night-sky-1-25-/p,6454

Sorry, my mistake. I powered it from the 20V output of a Maxoak K2 Li_Ion battery. https://www.amazon.co.uk/MAXOAK-Capacity-50000mAh-Portable-Notebook-Most/dp/B00YP823NA