Ocal Electronic Collimator Pro
Ocal Electronic Collimator ProOcal Electronic Collimator ProOcal Electronic Collimator Pro
Ocal Electronic Collimator ProOcal Electronic Collimator Pro

Ocal Electronic Collimator Pro

  (7 Reviews)
✓ 2 year warranty


5x in stock shipped 1-2 working days

"This is a very promising device. I am impressed at the way it alleviated much of the tedium of collimation, and its ability to reveal an unsuspected visual-back problem. I found version 1 of its software very useful and see great potential in future versions. I look forward to these eagerly." 

Review of the Ocal Collimator by Steve Ringwood for BBC Sky @ Night Magazine

About this product

Model:  ocal_ec_pro

NEW OCAL Electronic Collimator Pro for quick, easy & precise collimation! 

Updated manual kindly produced by Stuart Smith now available :-)

The Ocal electronic collimator is an ideal tool for carrying our precise collimation of Newtonian reflector, Ritchey-Chrétien, SCT and other types of reflecting telescopes.

Collimating using an Ocal electronic collimator is a quick, easy and comfortable experience making it possible to achieve an accuracy down to 0.08mm of primary mirror axial error. It can also be used to collimate the secondary mirror.

The collimation errors caused by different visual axis of the human eye when used with traditional collimation tools are totally eliminated when using a digital collimator.

Software is used to overlay several calibration circles over the image showing the primary and secondary mirrors allowing for very precise, repeatable alignment.

The Pro version includes an M42 to M48 adapter, an M42 to 1.25" nosepiece and can also be operated from a mobile phone / tablet as well as on a laptop or desktop like the standard version. Currently an Android app is available, due to high licensing costs there is unlikely to be an Apple version.

NOTE: Some customers find when using an Ocal with an unusually large (larger than 11") SCT or RC telescope they are unable to achieve focus and/or see the mirror edge. Especially if the telescope is fitted with an aftermarket focuser. 


  • Each Collimator has perfect pixel level accuracy with high quality control
  • Installing the collimator by M42 threads minimises installation error
  • The collimation errors caused by different visual axis of the human eye with traditional collimation tools is totally eliminated
  • The product can solve the problem of collimating large telescopes, with the assistance of collimation results shows on screen immediately
  • 4 steps collimation - It is easy and suitable for everyone
  • Can be used to check if the center mark of the primary mirror is set correctly
  • You can share your collimation result by screenshot and send to OCAL for technical support
  • Pro version also works on Android smartphones / tablets

Product Videos

(Pro Version only)

What's in the box

  • OCAL Pro Camera Body
  • 1.5m USB Cable
  • Android OTG Adapters
  • M42 to M48 Adapter
  • M42 to 1.25" Nosepiece

Downloads / Manuals

The following manuals and downloads are available for this product:


OCAL Software


OCAL v2 Updated Manual (PDF)

OCAL Original Manual (PDF)

Customer reviews

Average Rating (7 Reviews):  
Write a Review and share your opinions!

Rating (max 5):  
Excellent device but poor documentation
26 August 2023  | 

Using the Ocal collimator made collimation much less hassle on my 200pds & I was able to get a better result than with my laser / cheshire / cap / concenter + hand held camera. It also had the added bonus that I could check the collimation both with and without the coma corrector fitted.
One star deducted as I found the instructions hard to follow...
Superb service from FLO as usual!

Rating (max 5):  
Efficient Tool
15 January 2023  | 

I used OCAl pro for GSO RC 14 inch telescope. It is very efficient to project live display of primary/secondary and center point. software is good too.
It helped to achieve 99% correct alignment, but to simulate actual optical train a Howie Glatter laser is required too.


Rating (max 5):  
Excellent tool to help set up your scope accurately
19 September 2022  | 

I've used an advanced laser system (Howie Glatter's) for years to align my 18" Dobsonian. But I'm aware that this can not expose some errors.
The Oral collimator Pro came well packaged and relatively easy to set up. It comes with a USB OTG adapter to plug into a android tablet, but its USB C. My tablet and most others is Micro USB, but fortunately I had a micro USB version already.
I immediately could see my secondary was poorly placed and was able to get all components aligned using the Ocal. Adjusting the circle diameters on the tablet display isn't easy as the sliders are short and the adjustment needs to be fine. Just about doable though.
I have a SIPS (integrated coma corrector) installed in my focuser, which I had to remove to get a clear image. The manual says removing is optional but its not!
Once I had aligned with the Ocal I had everything pretty much perfect, only limited by the scale of the Ocal image, which even on maximum zoom cant show very fine detail. Putting my laser back in, I could see I was very close and just a small adjustment to the secondary got it perfect.
Overall, this is a very handy tool for setting up and checking collimation. I think you will still need a good laser if you have a relatively fast optical system that needs perfect collimation.

Rating (max 5):  
Great place to do purchase from
05 April 2022  | 

I am quite impressed with my first purchase from FLO. I live in USA and saw they had the OCAL Collimator Pro in stock, made a quick inquiry about delivery which I received a fast response and then placed the order. I was expecting a week or two for delivery but was blow away by how fast my item arrived. Got shipment notification on a Monday and package received on Thursday, same week. I don't think I have ever received an international shipment in 4 days! Definitely will come back to FLO first for future needs.

Rating (max 5):  
Problems down loading
04 March 2022  | 

It looks as if the OCAL Collimator Pro would be the Answer to my prayers after trying many other types,
Alas both my Windows Computers will not let me download the website details to bring the camera up. They say ,it is an UNSAFE Programme.
So what to do , how do other people manage it? Frustrated , but Hopefull , Brian


Hi Brian - this is down to the security settings in your browser or your anti-virus software. You will need to allow it to be installed before it will let you proceed.

Rating (max 5):  
26 February 2022  | 

The user instructions are not that clear especially regarding the Pro version on the mobile and the fact you have to copy in the Calibrator centering code from the downloaded spread into the mobile app as part of the offset. Otherwise it's an excellent tool for collimating all types of reflecting telescopes. I use it on my 8" RC and 180 Mak.

Rating (max 5):  
Ocal Electronic Collimator Pro
23 November 2021  | 

I have a Celestron C11 which I have had for quite a few years and have never felt the need to collimate it. However on seeing this product I decided to purchase it just to check that the scope was indeed fully collimated. It was easy to set up and use. Surprisingly the collimation was very slightly out. Something you would not pick up visually. I just had to tweak one of the screws on the secondary holder, and that did the trick. This product certainly did its job and was worth the investment.


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