OCAL Electronic Collimator RC Collimation Tutorial

[@tamartin7001]

Thank you Ocal, this voice over let me listen and watch, much better than the bird sounds🙂 - warning that with RC adjusting the secondary, your hex key should be fastened to a line in case it is dropped onto the mirror below. Happy Ocal RC customer!

[@HerbsGarage]

Excellent video ! Worked nicely on my RC reflector scope, after spending some time digesting what exactly needs to be done & when. A simple M42 to 2" adapter makes the ocal camera fit nicely and firmly into the 1.25" eyepiece holder. Use zero offset to do any mirror & focuser adjustments. Also, make sure in the final step that your tiny ocal image sensor is dead centered within the secondary black ring marking. Optionally, do a final double check with a laser collimator. The price seems right too for what this device offers.

[@tamartin7001]

Thank you for tackling a GSO 6-inch - I bought the Ocal collimator for the same OTA. Hearing that I can ignore the centre camera-mirror donut, is a relief - this never quite aligns in my RC6 either. The RC is a tricky telescope to collimate well, but there is logic for using a camera and concentric circles. I will still do a star test once in the field, and report back.

[@brianastrodoc2886]

I’ve been waiting for this tutorial, maybe now I can finally use my RC8. Thank you

[@jaq1967]

Good video. Just 2 points: 1. Where possible, screw the Ocal (M48) into the image-train rather than using an eye-piece adaptor and compression rings. Where possible you should use this method even when imaging due to possible flexure caused by this method of attachment - especially when you rotate your image-train when framing a subject. 2. The 'Offset' feature in the software should be kept at ZERO in the final adjustment. This is to ensure the image-train is inline with the optical-train. By all means use it for the initial Calibration but the 'Offset'' should be at ZERO in the final Collimation. You'll find by adjusting the secondary mirror this will achieve this. Ultimately you are aiming for ZERO 'Offset' and all your rings are concentric. Thank you for no birdy noises in this video. 🤣

[@ocalworld2776]

An offset of 0 is an ideal situation, but in reality it is often difficult to achieve

[@jaq1967]

@@ocalworld2776 Well... Users of this product should aim for ZERO Offset however difficult this may seem to achieve. Try, try again. If owners of this product are too relient on using this Offset feature then they need to prepare themselves for disappointment. 👍🏻

[@jaq1967]

@@ocalworld2776 See my other comment. If not zero then your image-train is not correct and inline with the Optical axis of the OTA. I'm assuming your Ocal devices are correctly calibrated to zero in the factory in support of this comment. Anything not zero is not ideal.

[@AshA-ww8hc]

I thought the OCAL is M42i Female threads, not M48?

[@jaq1967]

I've had another look at the video and found another problem: It only concentrates on making adjustments to the mirrors. It does NOT take into account if your imaging-train is central or not. Assuming that the Ocal factory calibration is correct and zero is zero, you should not use the offset feature. If you do, then it is likely your image-train is not inline with the optical axis of the OTA. This I discovered in recent tests I made. This needs to be tackled FIRST before you attack the mirrors. This is done by making adjustments to your focusing tube (if adjustable - my one is a Baader Diamond Steeltrack. This is adjustable.) or adjusting or adding a tilt plate (if you do not have one). The outer most circle in the image acquired by the Ocal (Optical Axis) is your guide. Leave your Ocal set to zero offset and create a guide-ring in Ocal to make the adjustments to your imaging-train so this Optical Axis circle matches your guide ring. Once this has been achieved, lock down your imaging train. You do not need to make adjustments here again. You then turn your attention to your primary and secondary mirrors. This part does not take long to fix Note: Do not panic when you are making those adjustments to the imaging-train and ignore what you see if everything in the middle looks poor! You will deal with this later by adjusting the mirrors. It is important the Optical Axis is correct. If this is not correct the rest is difficult to resolve, plus you may note you will have real trouble aligning the spider veins. There is a 9/10 chance your image-train is OK and does not need adjustment. I recommend this is checked first and dealt with if not. Regardless, I do not recommend using the offset feature in Ocal. If you do, then you clearly have a problem with the image-train not being inline with the Optical Axis of the OTA.

[@tornadoknut]

Hi Jacques, I received my RC6 with Steeltrack and the OCAL yesterday. After spending some hours to understand what the reference circle is, but this is still unclear to me. What is the sequence you follow? Cheers, Stefan

[@jaq1967]

@@tornadoknut Visit the Ocal group on Facebook. Search the links and have a read. It's too complex to simply write on this thread. 👍🏻

[@tornadoknut]

@@jaq1967 Thanks for that hint, Jacques 🖖

[@jaq1967]

@@tornadoknut The biggest tip I offer is do not use the camera offset feature in Ocal with the RC. Keep it at ZERO. If you find your camera is not central to the image then you have a problem. This will be likely to be your image-train not being central and you'll need to make adjustments to either your focuser or tilt plate (if used). Once established concentrate on getting your optical axis correct but adjusting the primary mirror. Then it's a case of making minor adjustments to each until everything looks inline. Keep an eye on those spider veins too. Make sure they're in line both in the optical axis and the secondary reflection. 🙂👍🏻

[@dummag4126]

@@jaq1967 Camera sensor is only a rectangle on focus plane. I don't understain what you intend whith Train. Focuser with mirror cell and baffle are one solid system that must be alligned. Don't tilt the camera, if you are afraid it will bend with the weight, screw it to the tube do not use a t2 insert.

[@indysbike3014]

Do you need to take the baffle from the primary mirror out when collimating?

[@scottfairbairn4790]

Great video and help, thank you!

[@brandlc]

I would really like to see a newer video using Ocal 3 on an RC that is not that well collimated and maybe different views clearly showing the parts of the camera view relating to primary and secondary. The latter part of this video (10.15) it basically says if blue circle is out of position (relative to what??) then move the red and green circles to make the blue circle more round. What actually needs to be altered to do this? Primary or secondary? Would be helpful to be a bit more explicit. In this example "we are lucky today and the result is fantastic". Unfortunately that's not helpful...would be better to so what to change if it was out. In the final part it states there is a different center please ignore this. What does this relate to? The camera or something else? (Using a cheshire it's obvious the centre point is the hole at the centre of the cheshire). My Ocal 3 is a pale green colour which the camera does not pick up well compared to the older red colour which adds to the difficulty in following the video whilst attempting to use the Ocal. I do understand the difficulty in translation and very much appreciate the attempt at the video but I think it could be a lot clearer.

[@johanenglund169]

I think last step you collimate in star test you should collimate sek mirror instead primary.

[@dummag4126]

hei attention, never collimate at the vertical position , if a tool falls inside is a big mistake!!!

[@spp2]

just tie your tools to a string so it when it falls in the tube it doesn´t scratch the main mirror. or replace the normal secondary mirror screws with screws that have a big knob to turn by hand ;) clear skies

[@abdelaidli]

👍👍

[@jayantibhaichauhan56]

Good , need practice to use it