How To Use A Barlow Lens.. Tips & Tricks 

I’ll let you know one of my tricks Jason. In refractors and Cassegrains( Schmidt and Maksutov etc) normally the 2x Barlow is inserted in between the diagonal and eyepiece. If you place the Barlow BEFORE the diagonal and eyepiece it becomes a 2.75x Barlow 👍

Hi Jason, I got my first telescope for Christmas (it’s just a basic StarSense DX102AZ) and your channel has been so invaluable, particularly for upgrading accessories. Got a Celestron 2x Barlow after watching this. Best astronomy channel on RU-vid! Cheers, Paul

New Astrophotographer here. That barlow lens is certainly much more dynamic than it first appears. I was using it all wrong, thus far. Thank you for sharing.

I really appreciate how you described what a Bar Len is. I have been looking through RU-vid and no one explained it so detailed like you. Thank you!😊

I've been watching your videos almost daily since I purchased my Astromaster 90EQ. I've learned so much from you and I really appreciate it. We had our first clear night last night and I got it pointed at Polaris and took a quick look at Venus. There was a black vertical bar going through Venus but I think I probably didn't have it focused correctly. I'll work on that next time! Correction! I was watching your videos even before my purchase. You helped me decide what to buy within my budget. Thanks again.

Wonderful video. Clear skies! I don’t think I appreciate my Barlow enough, it just...works! Clear skies.

You explained this perfectly thank you!

This channel is pure gold! I'm lucky to have found it!

Awesome video, and so informative! You just saved me from wasting money on a 3x Barlow flash deal on Amazon for my son's first telescope! Now I know the right thing to get him. Thanks so much. Keep up the great videos

Just brought a telescope and came with a Barlow and was a bit confused by its setup up. This cleared it up thank you very much sir

Thank you for all the tips and advises. I got my first telescope just a week ago and I am still learning to use it effectively. I find your channel is a great help. Many thanks!

i am new to using a telescope and have found your videos very informative and easy to follow,thank you.

Great video, clear skys

I gave my son a 100mm F4 tabletop reflector I fixed with a plastic focuser I modified so the eyepiece holder tube wouldn't wiggle when you tried to focus it. Just drilled and tapped 2 holes with plastic screws to hold the tube steady instead of its wobble. I taped a solar filter sheet to cover the 2.8" hole in the dust cover so he could check out sunspots if he wanted to. I set him up with a 20mm Plossl, a 10mm Plossl and a 6mm 60° fov, then instructed him about the Barlow's use . I told him to use the 20mm for the Sun as it was 20x which with the smaller hole in the dust cap it would be easier to see half the Sun and with the Barlow lens screwed on he'd have approx. 30x. No point to using the 2x as the 10mm was already 40x I told him that with such a short focal length going higher than 133 would be difficult to get clear views, but tracking a star cluster at 133x with a tabletop is difficult enough. Other than the plastic focuser being wonkie, but fixable it wasn't a bad little scope for $120 at the time. Something I read about the Barlow lens screwed into eyepieces was that the power could be a bit variable depending on its distance from the EP's lens. It isn't much 1.5 to 1.3 and it didn't seem a big variance.

10:07 pm May 15/23 Wish I'd found your videos years ago. You are BRILLIANT and you really know the importance of not assuming anything; plus, not using fancy jargon or abbreviations. MEGA THANKS!!!

Wow another great video, I'm learning so much thanks again Jason!!!

Clear skies, bro! You're the best!!!

Great video. All your video’s have been very helpful. Thank you

Hi Jason you mention the Swiss army knife and I must say it'd essential item I use when camping and it's sheer quality is outstanding! Barlow lens is that quality of the Swiss army knife and these lenses are great to have especially the good ones. I have a skywatcher one and it's so useful for refractors and reflectors. Love the tip you gave with your telescope and it shows these lenses have many uses! In out doors the Swiss army knife is simply the best item for it's many uses like tin opener etc. Barlow lens and Swiss army knife are for the out doors and everybody should own them in astronomy and camping. Both items are essential really as they are lightweight Compact and easy to use. Another great video my friend and stay safe plus clear skies too!

Thank you Jason!

Only been viewing for 6 years, but I've never owned a Barlow~ had too many questions. You just answered 'em all- thanks!

Best video I've seen on barlows. Thanks.

Great vid. Thanks for sharing

These Celestron Barlows are great!

Jason - I found this article on Barlows from Orion Telescopes & Binoculars that states that placing a Barlow lens between the focuser and the diagonal, instead of the diagonal and eye piece increases the Barlow's magnification power by another 50%; IOW: a 2x Barlow can be a 3X Barlow based on where you place it. The article reads: "a barlow lens can be placed before the diagonal, that is, between the telescope and the diagonal (Figure C). In this case the barlow’s magnification factor is increased by about 50%. So a 2x barlow placed between the telescope and the diagonal provides about a 3x magnification boost."

Very helpful video, right on point,

Thank You so much for all the videos on how to use all these things. I’m a real newbie to this and everything you have shown is making using my telescope way more fun.

You are by far the best in describing how and what to use and how to use it. Thank you.

Also called a T-Ring or M42 Lens Mount (that Svbony Barlow, standard 42 mm X 0.75 mm thread pitch), and available in M48, and M54 Lens Mount sizes. Keep spreading the good word!

This is the explanation wanted, great work. I myself are a visual watcher, but astrophotography is on my list. For now I ordered the Celestron 2x barlow, with some decent eyepieces for my Bresser 127mm/1200 achromat and my just ordered 102/500 Skywatcher travel achromat, lots of fun this summer in Italy I hope :) Thnx for you video I subscribed, greetings from the Netherlands.

Great video!I needed some help with my barlows😁😊

I bought the Celestron X - Cel LX Barlow and I love it.

I have Celestron Revalation 2x Barlow, which for the price is pretty forgiving. Great Overview of Barlow lenses and thanks for the tips! Clear Skies 👍✨

Great video!

Damn, another cool British fellow that I’d like to be pals with. Cooler than me by a long shot and way more interesting to listen to.

Damn that was insightful as hell cheers mate 👍

Just found your video and thank you. As an eye glass wearer, I have had enough of trying to take my glasses off and using the binoculars. I believe that I also need to get a better pair of binoculars as the eye strain is still there and probably the distance you describe is part of the problem with the eye cup. Thank you!!

Jason, brilliant. Although I am 66 years young I have gathered so much Barlow information from you. I love your site and watch it very frequently…sometimes the same video more than once. I have a Celestron reflector 130 EQ ( in a box because it’s not user friendly for me)however I love my Sky-Watcher 3.5 inch refractor on an AZ mount…… it’s brilliant. It just goes to show the best telescope is the one you will use ! Keep your site going. Happy Days. As always kind regards Ken ( Rutland).

im new here and gotten back into my two telescopes one i just got other ive had for a good 25 years but have all upgraded my eyepieces >>> i say that to say, NICE Job on your channel. Happy to be here. Have one myself. Very informartive and help me get back into it nicely. Thank you and keep up the good work.

Thanks again!

I have been pulling my hair out wondering how it works were it goes 🤔 great video and I have the feeling I will be watching a lot lot more of you, thank you for your time in making these videos for newbies like my self.

Great thanks

A standing Ovation to you my friend and at last some one who knows how to teach and make it easy and a joy to at last let the not so talented catch up ,indeed a Standing Ovation ,Brian

Bought the Teleview 2X barlow and use it with a SvBony 305 color camera and Baader semi apo filter and my Celestron 120 mm Onmi Xlt 1000f/l on my Meade XL70 mount with motors.

Thanks for explaining it to dummies like me. I got a budget refractor that Astro biscuit channel recommended, the Skywatcher Mercury 707. It comes with a Barlow and a 10mm and 25mm eyepiece. I managed to see Jupiter through the 25mm and we could see the moons as small lights at the side of it but not much else. I tried a Barlow but I couldn't get a clear image. Will try it again on next clear night

Thank you.

Right on Jason, they increase a telescopes focal length foremost. I rock a Revelation 2.5x Barlow, had it years, but I am tempted by the TeleVue 3x for planetary Lunar imaging.

Thanks!

thx bro❤

Thanks broskiiii

A lot of good information here . I thought the Barlow divided the lens mm,s and changed the power , you say it multiply,s the focal length of the telescope . I have been figuring the number the wrong way , tho I think it gives the same power figure maybe.

im new to you but i really enjoy learning and your videos have been really helpful, I just aquired a solomark f70070eq it came with a 10mm plossl and a 20mm plossl i dont like the finder on it as i have to look down the sight... id like to get an angle finder,,,could you make a recommendation on specific parts to upgrade this particular telescope as in lenses and a angle finder you like it would really help narrow down the field if you could recommend a few pieces....thanks

So these can be used as a focal reducer for regular camera lenses. Say, adapting old medium format lenses to a 35mm full frame format mirrorless camera to reduce the image circle size?

So as a beginner with a tight budget…I should get the Orion ST80 bundle then. Got it lol

Learning a lot from your videos! So as a beginner i have settled down on explore scientific 102/600 25mm 10mm plus one 2x Barlow with the twilight az nano Mount...not going for reflectors or mak though am very tempted.... thoughts on this? Should I proceed with it?

Nice .. probably gonna spend my money on proper barlow lens next time

Thanks for the video! This will help me pace myself and focus on learning before spending! That said, do you think it is possible to reach prime focus using a focal reduction lenses? DSLR camera sensor is still too far from secondary mirror and was wondering if a focus reducer lenses could help reduce that distance. Thanks!

I have the cheap barlow that came with my cheap original celestron scope , probably a single element It's something I have to improve on , even for my astrophotography , a quality barlow can make a bit of difference ,

I’m just getting started in hobby and I have learn a ton from your videos. I even properly balanced my telescope; I didn’t even know that had to be done until I watched your videos. So thank you so much! Also, any recommendation on a star tracker app or if I should even use one?

Hi, I'm a beginner and you thankfully make it easier to understand eyepieces, i have a Celestron Astro FI 130MM with no eyepieces. I'm looking at buying a 13-15mm, 23mm-25mm (i think) and a Barlow with a £250 budget, what would you recommend? Thanks Phil

"Do you actually need one" - I hope so because I bought one before openning this movie :). BTW. Great channel for newbies.

Do you recommend a 2" barlow for deep-sky astro in any way?

I have seen on sale 2X barlow lens that is mounted on the bottom of the eyepiece, the same way as a filter. It has a M28x0.6 thread. I intent to purchase it, since it is cheap. What is your comment on this ?

Hi Jason, I recent acquire a 3x barlow and maybe you know approximately the amount of power that I can obtain using the way that you describe in the minute 6:00, thanks for your attention

I own a Celestron 130 SLT telescope. I just purchased a 2x barlow lens. Will that allow me to see Neptune and Uranus as small blueish blurs in the sky? Not having any luck with my current lens that came with the telescope. Thanks for any input!

One question. Can i screw the lens (just the lens piece) of a 2X Barlow at the bottom of another 2X Barlow and what would the effect be ?

Can you do a video about trouble shooting a Barlow lens that won't focus? Especially 2 inch. I'm wanting to upgrade for my 10inch dobsonian and I know the 2inch can sometimes be troublesome and you might need a extension.

Yes it is a T and you also need to buy a T adapter for your pacific camera.to work. I just starting to take photos at this point. Thank you

My previous question on your video about eye pieces Why they are more expensive,after watching this,I noticed the first insert to double the focal lens Wasn't provided with the other lens they sell

Can we attach any barlow lens to any telescope? For example the BNISE F40070M

If I have a 1.25 T adapter and insert it into a 2" barlow will i get a 2" view?

Can you sugest me what is good barlow lens but that is under 70$

Love your videos Jason! Ok if I reference you on my videos?

You forgot to mention the barlow also increases the f ratio.

Heya, great video 👍. I'm new to astronomy and was wondering if I can fit any Barlow lens into any eyepiece - e.g. Celestron 9mm eyepiece + sbvony Barlow lens x2. Cheers

Great video. Can you use a barlow when doing astrophotography? I have a Skywatcher ed80 telescope with field flattener and thinking of buying a RedCat51 for a portable setup. I use a Sony a7iii camera, can a barlow fit in with this setup?

So if I was to use an 18mm eyepiece with a 2x barlow it will basicly make it equivilent to an 9mm eyepiece, but is the view the same? Is it as clear as it would be just using an 9mm eyepiece or does adding the barlow to the 18mm reduce light transmitence and make the image darker than just using the 8mm eye piece with out the barlow? Hope I'm making sence here. Thanks. Great video's. keep them coming.

Thanks for sharing! Brands? Models?

I had just purchased a Gskyer explorer 130EQ - It came with 7 lenses. I now know the 3barlow, but the rest are all Greek to me. There aren't any labels or engravings to tell what each lens size is. Is there a way of measuring to identify these?

JASON...................T- adapter for your Canon camera and a T ring for your Canon, the T ring electronically reads and allows your telescope to be your lens for your Canon. That part looks just like the camera body and your lens. The telescope is now your lens. If you have a Nikon you need to buy the T-ring adaptor to turn your telescope into your Nikon lens. Sony same way

Hi Mr. Jason, I have a question regarding the Barlow as you mentioned in the video that never over power the telescope with x5 Barlow and 5 mm lens it only will results in bad blurring image.... my question how do I know my maximum telescope power that I wont exceed it (my Telescope is Celestron Astromaster 130 EQ). and thanks in advance

I got my first rocky reflector telescope x 215. There's no vertical adjustment, I got bag filled with lenses but I don't know where to put them amd the whole tripod is almost flipping over by the weight from the metal brick in the bottom. 😢😮

Picked up a cheapy 750mm. Then got a 5x barlow and the 4mm eyepiece (cheap version, budget mattered. It was $20 vs $130)...i should see ants on the moon if its not too bad 😆🤦 or ants on the lens if it is. Using a cell phone for the good sensor. But didnt have much luck with the clamp contraptions (plastic one is loose and wobbly, metal one doesnt fit the camera focus tube (fits the 1.25" perfectly and fairly solidly)... so...bought a rigid carbon fiber phone case and a 42mm male camera to microscope eyepiece adapter, and will epoxy that to the case (alignment gods willing). Should make for a nice rigid reliable camera mount, that lets me screw the camera focus tube to the cell phone.

Hi Jason, Does the Barlow lense narrow the field of view, by that I mean, do you need to be more accurate with the sight? I had a some trouble getting to see anything earlier when I used the Barlow lense that came with my scope.

I've read that the SV105 camera has a field of view equivalent to looking through a 4mm eyepiece. My telescope has a 900mm focal length and an aperture / mirror size of 130mm (maximum recommended magnification of 260x). If I use a 4mm eyepiece that's a magnification of 225x so adding a 2x Barlow pushes the magnification past the maximum limit to 450x. As the camera field of view is similar to a 4mm eyepiece does the same limit apply? If I use a 2x / 3x / 5x Barlow will the camera get a blurry image?

will this also correct the image so it isn't flipped?

Usually, as with anything in life, you gain something at the cost of loosing something else... I was wondering, what are you loosing by using a barlow? is it exactly the same to use a 6mm eye piece with a 2x barlow, than using a 3mm eye piece? Thanks for this video!

Does the Barlow with the T thread also work with an eyepiece or can you only use it with a camera?

Upgraded my Celestron 2X barlow Ultima, with the Tele Vue. I can't tell a difference.

Just my luck. I replace the crappy plastic Barlow that came with the telescope with a proper one. Decided to stay within the same brand as the telescope and starter eyepieces. Turns out I can disassemble the Barlow in two places, but the thread does not match the filter thread at the bottom of the eyepieces. Sneaky...

Did you also mention that using a 2X Barlow also doubles the focal ratio of your scope? This can lead to a much dimmer visual image.

They go before a diagonal correct?

I've got a Celestron 130az dx. I've bought a 5mm x-cel lx and a 2x barlow, same model line. They don't work together. It should give me 260x magnification. but it isn't working. Am I pushing my scope too far???

I notice that the omni hasn't got the black housing?

Still trying to get my brain wrapped around the math here. My telescope is a 4.5” or 114mm diameter. So according to the first video of yours that I watched, the max magnification I can get out of this telescope is going to be twice the diameter, or 228x, yes? So if I was to buy a 5x Barlow that would extend the focal length of my 450mm telescope to 5 X 450 or 2250mm, yes? If so, I could use a 10mm eyepiece and that would give me 225X magnification, yes? That would give me the largest and clearest picture that my telescope is capable of producing, yes? Sorry for all the questions. This is my first telescope and I want to make sure I’m getting the best results without wasting money on lenses I can’t use. Thanks in advance for the help!

Hi, I bought the Celestron Omni x2 barlow and unlike the eyepieces, it does not sit tight in the diagonal. It moves and wobbles which is quite annoying. Is that normal?

The lower the number the more powerful the lens.

Well I don’t necessarily need one but I want one🤣

Apparently you can scratch the mirror by putting it on eye pice

Mine just... Don't work?