Make your own Focal Reducer

[@michs1708]

what a great little mod! simple and cheap solution! 👍

[@omg6630]

I have a homemade 125/1000 refractor. Please suggest me about the diameter of fr lense.

[@Ken_James_SV]

The diameter of the reducer lens must fit inside your focuser tube. Most common focuser tubes are 1.25" or 2".

[@garycwikla6385]

Great video and idea. Rather than using epoxy, you could use a UV curing glue like Bondic. It will give a quicker and cleaner result. It can also be built up for extra strength.

[@robinwoodbury2563]

Brilliant! Thanks for sharing with us.

[@luapynneb3069]

Great video , and great results! a saving of £100 over here in the UK, as i have just bought the celestron F6.3 reducer. still gona try this though and compare the two. Thx Pb

[@rayr1444]

Good idea. Will give it a go.

[@villemononen5303]

Thank you very much! Information presented nicely!

[@Ken_James_SV]

Thanks Ville. Glad to have helped.

[@EnglbinkHooperdunk]

Nicely done, I used to watch you on NSN

[@Ken_James_SV]

Thanks Vincent. I will be back broadcasting on Nightskiesnetwork.com as soon as this horrible long stretch of bad weather ends. It's been mostly cloudy here for over 6 months 🙁

[@EnglbinkHooperdunk]

No worries, I mean it's not like mankind is affecting the planet or anything. Right? :)

[@ril.y]

The problem I'm having is I have a small sensor camera with a full frame lens. This causes the field of view to be cropped 2.7x. So my 18mm lens becomes a 48mm lens. For the photography I take, the wider field of view the better. So I have an old rifle scope I will try this with. I will put the reducer inside the lens adapter and I hope it will work. This video helped a lot.

[@XRinger]

Wow, that was informative.. And you make it look pretty easy to do.. I've been worried about buying a good Focal Reducer. The cost of those things is all over the ballpark, but mostly towards the high end.. I've got an old Tabasco rifle scope that might be just the ticket.. :)

[@Ken_James_SV]

Richard, have a look at our Video Astronomy Forum. We have all sorts of tips in there: astrovideoforum.proboards.com/ In there I am Dragon Man : )

[@XRinger]

BallaratDragon I'm a member of a few forums (posting as XRinger) now and learning a lot about reducers and astro video.. It's a great hobby! Wish the weather would give me a break now and then.. :)

[@hovlandbound]

What a great idea. Thanks for posting!

[@NOLASkaGuitarist]

Nice results! If I were doing it, I probably would have taken a black permanent marker or black paint to coat the edge of the lens to reduce scatter and increase contrast. I also would have skipped the super glue and used just the epoxy so I could tweak the centering and get it perfect after I set the lens down.

[@thierrymartin8378]

before anything to paint in black the side of the lens

[@creativeleo]

Nice video, BTW to get shots with less noise and you can use Sky stacker software, it basically stacks multiple images taken of a spot using tripod which might have taken several seconds apart and stacks them to produce high quality final image after removing the noise and keeping all the details and stars. Actually I live in INDIA and I used DSLR to shot M42, using just tripod and exposure of just 1 second and I took around 600 raw images and compiled all of them into one final image. Basically software saw those images as 600 Second exposure and calculated what's important and what not for the final image. Just sharing the information, in case you're not aware about it. Thanks :)

[@Ken_James_SV]

Thank you Cleo, yes I do know about it. I was an Astrophotographer, but now concentrate on Live Astronomy Broadcasting on the internet using special high sensitivity Astronomy cameras in Telescopes. My old Astrophotography can be seen here: kzbin.info/www/bejne/aF61YpyGqMeMhbM But what I do now is here: kzbin.info/www/bejne/jX_NmoJ5gLRgmJo&t

[@williamhemmingsen7574]

Good tutorial Ken!

[@lachezarkrastev7123]

Great tutorial - I would not use the super glue, because its vapours are condensing over the glass and it is hard to be cleaned.

[@Ken_James_SV]

Thanks Lachezar, and you are Correct. That's why I don't use super glue any more. Just the 2 part epoxy glue. Much better results 👍

[@albertgonzales380]

what would I need to make one to fit my 1 1/4 any suggestions

[@Ken_James_SV]

+albert gonzales - G'day Albert, there are small Binoculars with 30mm Primary lenses. You could possible attach one of those lenses to a C mount 1 1/4" nosepiece. A 1 1/4" focuser is 31.75mm, so a 30mm lens will fit nicely.

[@albertgonzales380]

Thank you for your help, I just bought a used telescope and I'm trying to get the mirrors cleaned I'm having trouble finding people to do that here in Texas

[@XRinger]

found a defective Celestron f/6.3 Focal Reducer/Corrector on ebay. If the lens-pair is totally useless (they look bad in the photo), I plan to use the housing to hold a surplus lens, that's about the same size or a bit smaller than the Celestron lens. Maybe I can make a DIY FR without using any glue.. :) Going to try it out in a new C6 SCT. I'm about to buy a brand new Celestron f/6.3 FR. Not cheap! It's for my kid. She's got a DSLR and the 8SE.. She's never had any luck with DSOs.. That's about to change. :) After Dec 25 of course! Cheers, Rich

[@Ken_James_SV]

Good luck Richard. Let us know how it works : )

[@XRinger]

BallaratDragon The $15 defective Celestron f/6.3 came in, and it doesn't look real good around the edge of the lens. It might be contamination from glue, or the spacer..?. but when I tested it on the telescope, I'm not seeing the defect. The daytime outdoor view is excellent. So, I'll have to try it out on some stars (when the bad weather clears up), and see if it's actually OK.. If it's good, I won't be using it for a DIY project.. I'll just use it for astro video.. :)

[@Ken_James_SV]

Richard Lee Yes, could be Glue Richard. Celestron and Meade accessories are mass produced in China now and quality has been dropping over the last couple of years. Hopefully your other option works fine, using a surplus lens in the housing.

[@HibikiKano]

Very nice.

[@Ken_James_SV]

Thanks Axel 🙂

[@HibikiKano]

BallaratDragon How big is that cameras sensor? I wonder If I could make one for my camera as well :D

[@Ken_James_SV]

1/2 inch ICX428 EXview HAD CCD sensor 👍

[@HibikiKano]

Neat :D

[@gowdsake7103]

superglue and lenses not a good combo I would use a thin bead of epoxy for sure

[@Ken_James_SV]

Yes, thanks. It's been well established in the comments that Super Glue should not be used and I mention I don't use it any more. Thanks for your input 👍

[@nx7640]

thanx

[@Ken_James_SV]

Your welcome enix 👍

[@RynaxAlien]

You need to AR coated glass achromatic or even apo lens.

[@Ken_James_SV]

I don't 'need' Apo lenses. The majority of Focal Reducer are made from simple Achromatic lenses. Using Binocular lenses is actually higher quality than what is available in most FR's. And they ARE coated. If a person finds a broken or un-used pair of Binoculars with Apo lenses, well that's a bonus for them, but they are rare. I have several commercially made Focal Reducers that don't have any coatings. My home made samples are actually better than the ones I bought from reputable Astronomy dealers. The proof is in the results from use, not just theory.

[@quedecree]

Thanks Ken, I'll give that a whirl!

[@narcovice]

cc are hard to read cause its white and grey and cant see it. nice binoculars if you get it stuck use wd40

[@JohnBurgess37]

Could this method be applied to make something similar for a crop sensor digital camera?

[@Ken_James_SV]

I don't know. I am not familiar with Crop sensor cameras, or what adaptors would be need to this style Focal Reducer.

[@rayr1444]

Will work on any dslr, full of crop sensor. Has nothing to do with camera.

[@DawgcityClev]

Super Glue fumes will mess up the lens.

[@Ken_James_SV]

- Yes Paa, you are correct. Super Glue does leave a slight film on the lens, but I have noticed no change to the optical qualities. Probably because on mine the film left by fumes is only around the edge and nowhere near the centre. The small sensors in Video Astronomy cameras only use the central area of a Focal Reducer. I didn't use Super Glue on my last Focal reducer, just the Epoxy, and it works fine so I won't be using Super Glue again. Thanks for bringing it up so others can choose to use it or not. Preferably not.

[@johnendreson5502]

What side of the lens do you glue to the adapter? The side that was originally facing outwards on the binoculars?

[@Ken_James_SV]

The outside face of the Binocular now becomes the outside face also of the camera, so the convex side face towards the telescope. The flat side glues to the adaptor.

[@bengacz]

I've made focal reducer as it was on Your tutorial but it can't reach infinity (APS-C+ Newton 200/1000). With combination of 200/1000 Newton + APS-C it had like maximum 4meters of focus distance. I've tried to move the lens closer to the sensor, so i attached it to the other side of that metal thing but it still can't reach infinity. Any ideas ? Btw. what if i would turn the the lens in oposite direction ?

[@Ken_James_SV]

bengacz You will find that the sensor position in full frame cameras is a lot deeper into the camera than they are in webcams/security cameras/video astronomy cameras. You would need to get the Focal reducer closer to the sensor, or use a Focal Reducer made for DSLR type cameras.

[@LAshotts]

I’ve just realised. Is that nsn.ca you broadcast on. I remember watching you years ago on nsn ken.

[@Ken_James_SV]

Yes, I used to broadcast on Night Skies Network years ago, but one of the part owners of the site hijacked it from the other majority owner and ruined it, so now I broadcast on nightskiesnetwork.com which is the better broadcast quality site. The Video and Audio quality is far better, and Viewers can talk to the Broadcaster, not just type comments. It is a whole interactive broadcast site.

[@LAshotts]

BallaratDragon oh lol I’m on night skies network Facebook page. Admin is Crystal. Must admit I miss most of people’s streams though. Time zones. Glad your still broadcasting and maybe I will catch you broadcasting one day.

[@Ken_James_SV]

Ahhh Crystal! I'm Ken James LOL! We already know each other by our real names 😄

[@LAshotts]

BallaratDragon sorry ken I’m not Crystal I was saying Crystal is admin on the nsn fb page 😂

[@Ken_James_SV]

LOL, oops! sorry about that 😄

[@narcovice]

good tooth pick glue should try this want it dry fast use a blow dryer

[@ikifkif]

nice + clear

[@Ken_James_SV]

+ikifkif - Glad to help : )

[@narcovice]

how saturn

[@MrMarkPelle]

Great tutorial . realy like your stuff but buy a tripod for you camera. At least you will have both Hands LOL

[@Ken_James_SV]

I used a mobile phone LOL. But thanks for the suggestion, I do actually have a tripod. In future I will get someone else to hold the phone.

[@MrMarkPelle]

Keep making these vids. they realy are informative. I am new in to telescopes and i have been a photographer for years. seems like a natural progression as im getting on a bit. Thanks

[@Ken_James_SV]

Mark Pelle Mark, If you want to get interested in Video Astronomy, you can have a look at my Video Astronomy Website here: ballaratman.wix.com/videoastronomy It will explain the equipment needed. Video Astronomy is more exciting than normal Astrophotography because you get to see the objects near-live, and still take photos of them if you want. Best of both worlds - Viewing with an electronic eye and imaging. Here's a Forum devoted to Video Astronomy: astrovideoforum.proboards.com/ As light pollution takes over our skies, Video Astronomy is about the only way to easily observe most objects. Also have a look at my other Astrophotography Videos: The Astrophotography of Ken James Part 3

[@narcovice]

use wd40 if stuck to the fingers

[@MrMarkPelle]

Buy a tripod mate

[@Ked778]

Sorry if this is a dumb question, but can we keep the lenses in front of the camera lens to do the same?

[@Ken_James_SV]

No, a Focal reducer has to go BETWEEN a lens (usually a Telescope) and the Camera.