Ocal Electronic Collimator
Ocal Electronic CollimatorOcal Electronic CollimatorOcal Electronic CollimatorOcal Electronic Collimator

Ocal Electronic Collimator

  (14 Reviews)
✓ 2 year warranty


34x 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

NEW OCAL Electronic Collimator 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.

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

Product Videos

(Pro Version only)

What's in the box

  • OCAL Camera Body
  • 1.5m USB Cable

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 (14 Reviews):  
Write a Review and share your opinions!

Rating (max 5):  
Ocal Electronic Collimator
18 December 2022  | 

I ordered the Ocal electronic for my Newtonian telescope, it came just in time for the Xmas break, not had chance to use it, I will use it over Xmas break , always a pleasure to do business with FLO very FAST service & delivery & friendly staff, always keep up the work that you do, faster then any other delivery service, I know of, If i could, I would give them 10 stars rating.

Rating (max 5):  
A fantastic tool for collimation
16 October 2022  | 

I was a bit late to the party in finding this bit of kit but as they say ….“better late than never”
At £170 you need to be fairly sure it’s going to do the job, particularly as I had seen some mixed reviews on this product, so I talked with FLO and they assured me that if it didn’t perform with my telescope (250mm, F4 Quattro), I could return it for a full refund.
I’m glad to say that I needn’t have worried!
I have a permanent setup and use a Windows 11 PC and so I purchased the non-pro version.
The Ocal collimator appears very well made, well packaged and was easy to set up, with no connection issues. The updated instructions were very easy to understand and should be followed, particularly with regard to updating the config file with the centering code for your specific collimator.
There are few minor glitches with the user interface in the software, but these are minor and didn’t really impact my use of this tool.
Without a doubt, being able to follow all off your collimation adjustments on screen with reference circles and cross hairs, not only makes the process easier, it makes it so much more accurate. I still used coloured cards in the OTA to help identify some of the optical elements and made sure I re-focused the camera at each stage of the process, which is essential. Say goodbye to peering through pinpoint holes with blurry views, this is the way forward.
I love this bit of kit and will never go back to the old school methods. Thoroughly recommended!

Rating (max 5):  
Ocal Collimator
10 May 2022  | 

Works really good but I didn't really do it completely correct so will collimate again soon. It did help collimation out though from where I had collimated with a star prior, just need to spend another round to fine tune it and my 6" SCT will be spot on. Shipping from FLO was awesome and will use them again for future purchases.

Rating (max 5):  
Simple to use
26 April 2022  | 

I bought this camera to set up the collimation of my Celestron CPC SCTs as I am unable to use the classical methods due to my personal circumstances The product is well made and its software seems bug freee easy to set up However the product is half baked. I got the standerd version which comes without adapters and more importantlly and inexplicaby - wuthout any instructions
There is a cringingly awful anateur U-tube video and an even more awful and strange unwatchable pidgin video from the manufacturer specific to SCTs which were of some help - but all other material is directed at other optical types Indeed the apparatus was designed for use with Newtonian reflectors, although it can be used for catadiopreic instruments
Anyway I have used the camera to collimate a spare C8 SCT OTA after buying a set of Bobs knobs and in about half an hours work I have managed to get to the stage that the video assures me is exact collimation I will soon repeat the procedure with my CPSs - when I pluck up the courage

Rating (max 5):  
Almost there
25 March 2022  | 

I have an 8 inch RC and I've just purchased the Ocal Collimator to check and adjust it. The downloads are easy enough and the copy/paste transfer is an awkward step only.
Firstly do rotate the camera in the focuser to see how decentred it is and select the closest point to centre. Also don't just loosen off all the screws holding your optics in place, slacken only enough to make the adjustments and watch the screen to see which screw moves the image in what direction. Things I've just found that I feel others might find helpful: move your focuser in/out so the image of the primary is just smaller than the image of the inside end of the tube, the annulus of light around the primary will help with centrring. When you size the circles (principly Green & Red) make them sightly larger than the component your adjusting that will give a similar annulus to aid adjustments. A further indicator is to look at the lengths of the spider vane anchors and see how far each intrudes into the edge of the image. I set the length of the cross to the same radius as the spider anchors and adjusted until each spider anchor touched the cross.
Remember also that with OTA's that have the primary fitted to the back plate then this becomes an iterative process of making course adjustments then refining them.
To maintain your focal length only adjust two of the screw pairs on both the primary and secondary. Adjusting all three pairs will change the mirror spacing and lead to a focal length change which on folded optical systems can be quite dramatic.
I'm hoping to test the scope tonight and see if a star test is needed (probably).

Rating (max 5):  
Collimating Celestron Edge HD 8
11 March 2022  | 

I purchased this item to help in collimating the Edge HD8, while I understand you can use a star during the night after watching a number of video's of people trying this out it does seem a lot of hard work and very time consuming. My first usage of the Ocal Electronic Collimator I could do it form the garage and setup to finish took around 30 minutes and you can really fine tune your collimation very easily.

Rating (max 5):  
Brilliant collimator, a must have item
10 March 2022  | 

I recently bought the orcal collimator to collimate an f4 Newtonian telescope that I've been struggling to collimate since the time I'd bought it second hand two years ago. Well, enough of history, this bit of kit although expensive is worth it and easy to use. A bit of YouTube vids and off I went. It showed the focuser was tilted and secondary mirror too. I've tried with Cheshire and laser collimators to no avail but this bit of kit collimated my f4 Newtonian wonderfully and confirmed what was out of place. Definitely a keeper. Thanks FLO.

Rating (max 5):  
Expensive, but a keeper.
09 March 2022  | 

Firstly, don't expect to just plug and play with this thing, I did and it wasn't pretty!

The very first thing you HAVE to do is download an Excel file from Ocal's website and find the Calibrator Code for your individual unit. Then you have to update and save a .txt file within the zip file from the downloaded software, then and only then can you get started. This all sounds like a bit of a faff and it is, but once it's done it's done, and if I can do it anybody can! (I recommend watching the Youtube Tutorial (with the sound down!) rather than reading the PDF.)

Once calibrated, you could easily spend hours and hours getting your scope perfectly aligned, especially if your collimation technique is just 'twist and hope' like mine! That being said, after a couple of goes I'm sure I'll speed up and wonder how I ever got by with just the Cheshire collimator!

Not sure it's worth the £170 price tag though!?

Rating (max 5):  
Good device, happy with my Purchase.
05 March 2022  | 

Reason for purchase:
I found the large amount of choice for collimation devices a bit overwhelming with products claiming to be the best, the most accurate, the fastest, the easiest to use and each product having several reviews and write ups either advocating their use or warning me off buying them for reasons x, y, z. In the end I opted for the Ocal even though it was not the cheapest solution because for me I liked the fact that it is a camera based solution that takes the guess work out of the process and is perhaps / arguably less subjective than some solutions out there.

Using the product:
Set up and use of the software is reasonably straight forward. The instructions are not great but after some study I grasped the physical process they were trying to describe and then it’s pretty easy to figure out what needs to be done and in what sequence to get a good collimation. For accurate alignment into the 2” focuser I have purchased an adaptor that has a 2” tube on one end and a 42mm thread on the other. Amazon £15 and 3 days. This ensures a good fit to the scope which is crucial in my view. At £169 for the OCAL this should be in the box I would suggest.

The view down the scope on my laptop screen is good and there are sufficient controls over the camera to get a decent focus, contrast and brightness of image. Setting the circle sizes in software to match the exact size of the focus tube lower edge (for example) is straight forwards. Using the offset controls the first circle in software can be aligned spot on target – and the rest of the alignment flows from there.

The hardest part of the process for me was physically making the adjustments to the mirrors to bring everything to the right position. This shows more a lack of experience on my part than anything and is true of any collimation device being used. What I would say however that is having the large bright image on my laptop whilst comfortably adjusting knobs to move the physical parts of the optical train is a very ergonomic way of doing it – compared to peering down a sight tube for example. So for me this is one of the key benefits of this system and this alone makes it a good buy.

There are a couple of niggles in the software – fine tuning values using the sliders was clunky with my mouse, zoom steps were not as fine as I’d have liked with the mouse wheel, and it is a slow-ish camera in terms of response time. If OCAL were to invest a bit more time to refine these features of Software it would make for a superior user experience. These are pretty minor gripes however so don’t let this put you off.

Any collimation device that locates in the eyepiece holder will be subject to small variations in position each time it is fitted and locked into place just by virtue of the tolerances of the manufactured parts and the nature of the clamping mechanism. These variations are small but exist and can impact collimation repeatability. After I had collimated my scope I had a play with the device by removing and re-fitting the OCAL into the EP holder and re-tightening. I did this a dozen or so times and was trying to observe the degree of mis-alignment that I was getting with each insertion and removal. (sort of a simplified Gage R&R test for any Engineers out there). I was actually nicely surprised by how much (little) variance I observed in this simple and somewhat crude test. Although it is most definitely there overall I’d say if the OCAL is placed in the EP carefully and locking screws gently and evenly nipped up the device is positioned pretty much bang on where it should be on each insertion / removal. This for me gives some confidence that the collimation is both accurate and repeatable.

I see the OCAL an investment that hopefully gets the most out of my telescope and a good long term purchase because it can be used on any scope I purchase in the future. It seems accurate, easy to use and repeatable. For what it is – a small camera and a simple piece of software – Yes, it is expensive. But it is still a good purchase in my view for all the reasons outlined above.

As always - FLO were fast and efficient in terms of the purchase and delivery process.

Rating (max 5):  
Good and useful - but be aware what is it and what it is not
03 March 2022  | 

I knew this before purchasing, but I wonder if some don't - hence the returns. Basically this is nothing more than a calibrated centred camera and a bit of software that draws circles over the picture. That is not a negative, it is simple a statement of what it is. It does not in any way automate collimation, but it does make it a heck of a lot easier, quicker and more precise. the big differences for me are, you can be looking at a sharp focused picture on laptop rather than blurry thing through a cheshire. you can be assured of exactly where centres are with the circles. you can SEE the output when adjusting primary. the electronic focus is key here - letting you get a sharp mirror edge, etc. The resultant collimation is far less painless, and more precise. Do be aware that the manual is terrible. If you do not know how to collimate, I would advice you to learn first (search astrobaby collimation on internet) or the chinklish manual may just confuse you.

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