Nice video! Back focus recently clicked for me as i thought i was measuring from the actual glass lens and not the threaded ends of my focal reducer. Your explanation is excellent and i've watched hours of other video on the subject with thousands of view and you cracked it in 3 mins! BRAVO my dude!
Great video. However it's a bit more difficult with a Canon DSLR + Starizona 0,63x. The sensor sits 44mm deep inside the body of the Canon. The lower version of the bayonet adapter is 1,5mm high. This is 45,5mm. So to get 90,3 mm, you need 44,8mm train. A solid and pretty straight train. I'm struggling with this for couple weeks. So I looked for a lather guy who will make me the correct length adapter in one piece.
Hi, thank you for this and other videos. Wow, this back focus stuff is a nightmare. I have a C6 SCT and to use the Celestron adapter (93633) with my Nikon DSLR is easy, but I would like to connect my ASI585mc camera instead and include in the regular f/6.3 reducer and a single 2" filter drawer that I already use with my AstroTech refractors. I can't get the changes in diameter of the extensions along with male/female threads changes. It becomes literally impossible! I noticed you slipped the assembled tubes into the reducer. Is there also a tube that has the standard SCT threads (seemingly 50mm) to fit a 2" eyepiece/tube that you know of?
Try Agena Astro! They usually have all kinds of adapters. My visual back is SCT threads on the back and it accepts 2” accessories (which is what my focal reducer is 2”). Best of luck!
@@txdave2 It will if you’re using a field flattener. You’ll have to get the right spacing between the camera chip and the field flattener for it to correct properly. If you’re not using a flattener then no.
@@guyjordan8201 Correct. Focusing a CCD camera requires a certain spacing between the telescope and the CCD chip to achieve a flat field for astrophotography. Completely unrelated to visual observing with an eyepiece
![Telescope Back Focus: The Ultimate Guide [TAIC Short]](http://i.ytimg.com/vi/5J654T0UpBc/mqdefault.jpg)
Short and sweet and to the point!!!
Nice video! Back focus recently clicked for me as i thought i was measuring from the actual glass lens and not the threaded ends of my focal reducer. Your explanation is excellent and i've watched hours of other video on the subject with thousands of view and you cracked it in 3 mins! BRAVO my dude!
Thanks! I have been struggling to calculate back focus with the Starizona reducer and was pleased to hear that Starizona makes the 35.3mm adapter.
Great video. However it's a bit more difficult with a Canon DSLR + Starizona 0,63x. The sensor sits 44mm deep inside the body of the Canon. The lower version of the bayonet adapter is 1,5mm high. This is 45,5mm. So to get 90,3 mm, you need 44,8mm train. A solid and pretty straight train. I'm struggling with this for couple weeks. So I looked for a lather guy who will make me the correct length adapter in one piece.
I have a refractor so is it 55mm from optical tube to sensor. I have zwo 2600 mc pro camera.
Simple and easy explanation 👍🏼.
Hi, thank you for this and other videos. Wow, this back focus stuff is a nightmare.
I have a C6 SCT and to use the Celestron adapter (93633) with my Nikon DSLR is easy, but I would like to connect my ASI585mc camera instead and include in the regular f/6.3 reducer and a single 2" filter drawer that I already use with my AstroTech refractors.
I can't get the changes in diameter of the extensions along with male/female threads changes. It becomes literally impossible!
I noticed you slipped the assembled tubes into the reducer.
Is there also a tube that has the standard SCT threads (seemingly 50mm) to fit a 2" eyepiece/tube that you know of?
Try Agena Astro! They usually have all kinds of adapters. My visual back is SCT threads on the back and it accepts 2” accessories (which is what my focal reducer is 2”). Best of luck!
Excuse my ignorance. Does this apply to a ZWO camera attached to a Newtonian scope?
@@txdave2 It will if you’re using a field flattener. You’ll have to get the right spacing between the camera chip and the field flattener for it to correct properly. If you’re not using a flattener then no.
Very nice
Still does not answer how backfocus is different from just plain focusing.
Backfocus is for CCD cameras. Not for your eyes just focusing an image with an eyepiece
@@MaximumAstronomy So is the issue that you need extra focus distance for the CCD?
@@guyjordan8201 Correct. Focusing a CCD camera requires a certain spacing between the telescope and the CCD chip to achieve a flat field for astrophotography. Completely unrelated to visual observing with an eyepiece