Barlows - is it just me or are they tough to use?

[MattJenko]

I have all kinds of problems with barlows. Here are the main gripes

1. They are extremely difficult to focus with. When I say extremely, I would say next to impossible for me nearly all the time I have tried.
2. They darken everything
3. They are just too sensitive to any vibration, tweak, nudge.

Do I just not have the fine touch required and am too ham fisted to be trusted with a barlow?

[acey]

Difficult focus is most likely because you're working at higher magnification, but may indicate aberration in the barlow.

Darkening is because you're magnifying more, and to a small extent because you're introducing more light-absorbing glass.

Sensitivity is mainly because of higher magnification, but increased height of eyepiece from focuser could be a factor.

So mostly I think your complaint is about high magnification, in which case stick to lower.

I have a barlow but never use it. If I want higher magnification I use an eyepiece of the required power. Most "ultra wide angle" eyepieces have, in effect, a built-in barlow (the lens at the bottom), which is a negative lens like a barlow, but is there as a field flattener. A barlow can serve as a "poor man's zoom" if you just vary how far into the tube you screw the eyepiece: the distance to the barlow lens determines the amount it multiplies by. But as you slide the eyepiece in the barlow tube you need to refocus. A better option is to get a real (good quality) zoom.

On reflection, I do occasionally use the barlow with my little f4 refractor. But that's about it.

[michael.h.f.wilkinson]

+1 for acey's remark. High magnification is hard, especially if the scope wobbles in any way

[David Smith]

I have barlows but use them mostly for imaging these days. Like you I found them difficult in use but mostly because I was trying to use too high power. Once you realise the limitations of your scope and the seeing / transparency conditions you can work at a more practical magnification. I also have a good range of eyepiece focal lengths now so really have no need for a barlow for visual.

[jnb]

Are you using the stock barlow that cam with your scope? The barlows you get provided with scopes are notoriously bad, even worse than the standard eyepieces.

[rwilkey]

I never use a barlow although I have a good quality one, I have recently bought the ExSc 2x focal extender but have yet to use it, all reports say it is good.

[Wazzat]

Hi MattJenko,

It's not just you!

I'm another who has the barlow that came with the scope, but never use it. Much better to use a different eyepiece instead. It depends what you want to look at, but I find I don't use high magnification much at all. I prefer a smaller bright image rather than a bigger, duller one, most of the time.

[Stargazer33]

I only use the barlows for astrophotography. I have a Revelation Astro 2.5x barlow which I use most. I also have an ExSc 5x focal extender, which to be honest is really too much magnification, so I hardly ever use it. If I want BIG magnification I put my 12mm XCel LX ep in.

[Stu]

I mainly use a Barlow in two instances. Firstly I have an 8.9 to 17.8mm zoom, which I need to Barlow to get to high enough power for planetary viewing.

The second case is when I am using Ortho eyepieces with tight eye relief. The Barlow not only increases the magnification, but also extends the eye relief making them more comfortable to use.

A Barlow is still governed by the same rules as stand alone eyepieces. Stick to combinations which give magnifications within sensible limits and you will be fine.

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[D4N]

I use mine with a zoom EP too, gives a huge range of magnification without faffing around switching EP's.

TSED70Q, iOptron Smart EQ pro, ASI-120MM, Finepix S5 pro.

[MattJenko]

Thanks all. I have the Baader Barlow which goes with the Hyperion Zoom I also have. I must say I simply prefer using the zoom on its own and will buy a dedicated higher power EP for those planetary and double nights and when the seeing is good and the power urge comes over me on those faint objects. I was hoping for a small EP collection with the barlow effectively delivering the higher magnifications, but this is exactly where my problems with it are. I hadn't thought of it as a means to increase eye relief though, that is an extremely interesting observation - thank-you.

[Stu]

Thanks all. I have the Baader Barlow which goes with the Hyperion Zoom I also have. I must say I simply prefer using the zoom on its own and will buy a dedicated higher power EP for those planetary and double nights and when the seeing is good and the power urge comes over me on those faint objects. I was hoping for a small EP collection with the barlow effectively delivering the higher magnifications, but this is exactly where my problems with it are. I hadn't thought of it as a means to increase eye relief though, that is an extremely interesting observation - thank-you.

The eye relief extending can be a benefit or a nuisance depending upon the eyepiece being used.

With shorter focal length Orthos and Plossls it is generally a benefit, but with say 32 or 40mm Plossls, it can make the eye relief uncomfortably long and hard to get on with.

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[swamp thing]

I use a barlow every time I observe. aceys comments are correct in that the problems you are finding are what high mag will do anyway.

I find there is no difference between a dedicated eyepiece and using a barlow eyepiece combination. 

Using a quality barlow will indeed cut the number of eyepieces you need to buy down. 

e.g. With my 10" dob I often use just one eyepiece and a barlow all night.

Rather than using plossls from 10-32mm I can use a 20mm Nagler + 2" powermate.

[mitchelln]

The eye relief extending can be a benefit or a nuisance depending upon the eyepiece being used.

With shorter focal length Orthos and Plossls it is generally a benefit, but with say 32 or 40mm Plossls, it can make the eye relief uncomfortably long and hard to get on with.

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The Televue Powermates do not suffer from this. They do suffer from severe wallet denting though! 

I have to say my 4x Powermate has given me the best views and photos of Saturn so far. Can't wait for Jupiter to come round again at a sensible hour.

[Stu]

Very true. I loved my x2 PowerMate, very effective but I found I didn't use it so much.

Lovely Saturn image :-)

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[LukeSkywatcher]

I have all kinds of problems with barlows. Here are the main gripes

1. They are extremely difficult to focus with. When I say extremely, I would say next to impossible for me nearly all the time I have tried.
2. They darken everything
3. They are just too sensitive to any vibration, tweak, nudge.

Do I just not have the fine touch required and am too ham fisted to be trusted with a barlow?

Out of those 3 comments, the only one i agree with is the 2nd. They do tend to darken your view. This however depends on the quality. I read once that a good quality barlow should be unnoticed while using it. It wont darken the image. 

The focus on them should be very little in difference between using it and an EP and just using an EP alone. Because they magnify everything by a factor of 2 or 3 depending on which type you use, they may seem to increase the vibrations involved while focusing. 

[MattJenko]

It might just be me, but my subjective experience with a couple of different barlows now both point to them being much more sensitive to focus, either a shrinking of the acceptable focus window, or maybe just worse effects for a similar out of focus pure eyepiece. Either way, it is a real thing for me in that I find them much harder to get any kind of decent focus. I agree that point 3 is probably a symptom of point 1. It certainly doesn't feel like just using an eyepiece. Maybe other posters are right in that I am only using the barlow at the higher magnifications and this has a lot to do with it.

[D4N]

I was using mine at x135 today on the sun and had no problems with focus even though that is near the limit of what I should expect from my scope.

I was also unable to see any difference using the zoom EP while using the same magnification with and without the Barlow in place.

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[MattJenko]

Hmm, my experiences are certainly not universal then. I will endeavor to give my personal optical abaddon another chance of redemption. Thanks again. 

[miguel87]

I love Barlow...

[ghostdance]

My first Barlow was a TP or similar, 2x....gave up using it much after a bit as everything went to bit too dark & optically it didn't seem great - it was OK but not so snappy but was only £15-£20 ( I forget)....then I became seduced by the TeleVue 3x Barlow (£60 odd) & that is just plain lovely. I use it tons. Optically it vanishes (or seems to) which is just what it should, is snappy as all get out and is very nicely built. I wouldnae be without it, Cap'n.

Based on this & one of their plossls, I could seriously get the Green & Black habit...( wallet runs away screaming....)

Steve

[Qualia]

If I'm working on planets and I'm in the mood for them, I prefer to use the line of orthos I have, incrementing magnification step by step, so I don't lose the object whilst I'm tracking it with the dob. However, similar to Swamp Thing, if I'm working on DSOs for the evening, I prefer to use just two EPs (14mm and 10mm Delos) and a TV x2 Barlow. With the 10" f5, this set up covers me for most of my work on globulars, galaxies, planetary nebulae, and double stars offering magnifications of 90x, 125x, 180x, & 250x.

Often I find it difficult to find an object at high magnification, so what I do is make sure the object is centred in the field of view of a low power eyepiece and then as quick as possible place the Barlow in the focuser and fill it with that low power eyepiece. I then recentre the object and if need be, place another EP in the drawtube as quick as possible.

Usually, on the focuser the knob if turned in a clockwise direction will move inwards, and an anti clock direction will move it outwards. If this is so on your scope, to focus a high power eyepiece, you turn the focus knob so that the eyepiece moves towards the scope and you turn it the opposite way to focus a lower power eyepiece. I say all this, for sometimes this part of the game is crucial and often is the difference between losing the object or being able to settle into a high-power contemplative study. Focus will always be very critical at high power, so very small focus movements will be needed to get it spot on.

My feeling on this is to give the Barlow some time, and I'm sure you will soon get used to the feel of it  Whether you like using them or not is a completely different matter, some do, some don't

[mitchelln]

Top DIY focusing trick is to find a plastic bottle top that smugly fits over the focuser knob. Then attach a lolly stick to the bottle top. You instantly achieve 10:1 reduction (depending on the length of the stick)

[Charic]

Start using your  Barlow with your larger focal length eyepieces and work down until you find whats best for your needs. I can get 240x using my 5mm BST on the Moon, which gives me good results, but when I barlow at x2 , I get  480x and expect to see, well, not a great deal on the field of view, especially on the Moon, but I am looking inside a crater, within  a crater and so on. Again truly stunning. Only at this type of magnification, you need to push the Dobsonian to stay on target? I'm also considering buying another Skywatcher x2 Barlow, to help speed things up a little? I normally just use the Barlow cell without it's sleeve, so in effect I may be viewing at about x1.6 factor. This is fine for my requirements, but have to keep changing the Barlow lens cell for each eyepiece, so maybe another cell would allow me to prepare my next Barlowed eyepiece whilst viewing through the first! 

[MattJenko]

With all the replies, it appears that in summary I am simply too quick to dismiss an entire suite of optics (which is good news), that I am too heavy handed with my manual focussing (again good news of sorts), and finally that I am pushing things too hard at high magnifications (just too darn eager). Onwards and upwards.