Loupe / eyeglass / eyepiece

[jdm]

1 hour ago, ajdo said:

Thx JDM. Yes, have heard good things about ASCO loupes. Their are supposed to be on the higher end a fairer price wise. 

ASCO is just the company name as "white label ". Would be good to know if lenses are glass on the cheap ones, and if the CHF 234 ones can be insured 

[measuretwice]

Quote

I am looking for loupe(s) with a nice glass. From experience in another hobby, I learned a nice less magnified glass is better than a lesser glass quality at higher magnification.

 

A good topic.  I only have crap loupes, and its likely a problem.  With them, 10x often doesn't feel like enough for lathe work.....perhaps better glass would change that.

I had a young watchmaker over not to long ago.  He did years in school in Switzerland and has his own business so is not a wannabe (like me).  He said he spent over $100 on his loupe.  Not sure where you go to get a loupe that expensive, but I guess the point is he felt it was a crucial tool where you should get the best.  Probably something to consider in that.

On all my cheapos, I've ended up grinding slots in them so they don't fog up.  I think Bergeon has one with slots, but I always wonder why it wasn't more of a standard thing, no one else has them fog up?  I also use various DIY rigs to hold them on my head - it always seem about impossible to hold onto with they eye for more than a minute or os

 

[ajdo]

Much appreciated. I tend to agree with the young watchmaker you know. By-once-cry-once and enjoy the hobby more.

From upgrade experience in other hobbies, without going overboard on desired items, one spends more on upgrades than buying right away what they would feel more comfortable with. It’s like running with flip-flops instead of getting running shoes  Also good tools are re-sellable. Although I also understand higher cost tools may be an issue.

Will post my findings after my research and gathering other people’s input. It may help other newbies get into this hobby more easily. 

Thank you... AJ

[nickelsilver]

The really expensive Asco loupes are achromats, the next level down (140 bucks) are aplanatic. As I've always understood, achromats are usually also aplanatic, so they deliver accurate color and an undistorted view across the lens. Aplanatic might have some color error. The color gets important when dealing with precious stones but isn't an issue for us watchmakers. I have several of both, and honestly can't tell which is in my hand without looking at the loupe body to see.

In lower powers, the aplanatic issue is sort of a non-issue, as the simple single double convex lens delivers a good image. In higher powers it's almost a necessity that the loupe be a double lens design or there is awful distortion. Most good brands go to double lens groups (two single convex lenses) at around 10x. Seems like there used to be more offerings of double lens loupes in the 5x-ish range, I have a Wild Heerbrug 5x with double lenses and am pretty sure I have an old Asco or Bergeon or two lurking around here the same.

I think all the current offering from the Swiss suppliers are good, you can't go wrong with Asco/Bergeon/Horotec.

[ajdo]

Much appreciated @NickelSilver, could not find any clear technical information about watchmakers loupes on internet that made as much sense as what you wrote. 

I am sure others will benefit as well from your wisdom on the subject! 

Actually, after your explaination, JDM’s link from this morning is much clearer. It shows the type of glass in ASCO loupes:

http://www.schurch-asco.com/e-shop/catalog/index.php?cPath=114_115&osCsid=d8c3a6eb43bf762fdb59e1e15c3a6fc7

Thank you... AJ

Edited June 11, 2019 by ajdo

[ajdo]

A more comprehensible ASCO product data sheet :

http://www.schurch-asco.com/e-shop/catalog/pdf/english/90_loupes.pdf

[nickelsilver]

Just dug through some loupes and found a Sandoz 2 1/2 (4x) double lens aplanatic, so there's another name to search for when trawling Ebay and elsewhere. Sandoz was a big supplier like Horotec back in the day.

[praezis]

I have a lot of those Indian aluminium loupes (no. 2...3.5) lying around in my workshop, handy like ball pens.
Today I compared one with a Bergeon 4422 that I use on my bench.
Both are single glass lens. With naked eye I could not find any advantage of the Bergeon. Same sharpness and clearness, same blurring around the edge.

Frank 

 

[Khan]

Hello

I realized that I mostly use x6 mag?, distance 45 mm and object display 33 mm, why I now understand it makes me tired because I tilt face to check a lower level of a movement. 

I hear x4-5 mag is most common and therefore acquired an aplanatic bergeon loupe no. 2.5 with x4 mag. But it works at a distance around 40 mm which is near x6.7 according to attached info from CousinsUK. Seems not right?  Should I buy a standard version? 

I want a loupe for the general screwing and unscrewing major wrist watch movement components, where I can keep the neck stretched and the screw driver away from cheek. I imagine 70-90 mm and strong enough magnification to display a movement around 35 mm. 

Edited October 11, 2019 by Khan

[TheFixer]

I don't use a loupe for assembling unless checking parts so am I odd? I have no difficulty so far in fitting parts.

When I do use a Loupe it is 10X.

[Khan]

Hi TheFixer

Well, I believe good lighting makes it easer.

Despite a good sight, I feel more comfortable using loupe when a tool gets in contact with a component. 

Hand motion is more controllable under a loupe due to reach, which prevents slippery of chosen tool. 

But thats just my opinion

 

Edited October 11, 2019 by Khan

[TheFixer]

1 minute ago, Khan said:

Hi TheFixer

Well, I believe good lighting makes it easer.

Despite a good sight, I feel more comfortable using loupe when a tool gets in contact with a component. 

Hand motion is more controllable under a loupe due to reach, which prevents slippery of screwdriver and scratches. 

But thats just my opinion

 

lighting I need to improve.

[oldhippy]

Normal for me was 3x close work 2x 

[stevew]

I use a 3.5x, obviously 10x is good for checking parts. I use Cousins clip on as i need Glasses for Reading etc. As said lighting is very important, surprising how things look so much easier. But we all have our own ways, and techniques, so best to find what your most comfy with.

[Nucejoe]

I try all loupes to see which one is most common for you.

[sjhilbel]

Have any of you tried Dental/Doctor Magnifiers? I've found I need stereo vision while working on movements. I get migraines frequently and I've found the single loupe to trigger them. I currently have a visor that just doesn't stay in place, so I was hoping someone had experience working with these.

[jdm]

These are uncommon among watchmakers. Since the object you're working on is small and doesn't move, unlike an human, when strong magnification is needed a stereo microscope is used instead.

 

 

Edited June 24, 2020 by jdm

[JGrainger]

I'll be interested to see if anyone's using this type of magnifier, the different models vary in magnification and working distance.. I just dislike loupes, and tend to spend a lot of time with my microscope - which is great but not always ideal for everything.

[nickelsilver]

I invested in some Carl Zeiss binocular magnifiers some years ago. They are fairly adjustable, but if you have different doipter needs for each eye are useless. They are only 2.3x mag, compared to 3.5, 4, or 5x which is typical. The working distance is quite large though.

I put them on sometimes, but honestly if I'm the least bit struggling with my 3.5x loupe I slide over to the binocular microscope. Way easier. I highly recommend AO (american optical) scopes, they are under the radar and equivalent to modern Leitz and Nikon scopes. You can always get a dud though (true for any scope 30+ years old).

There are some new "magnivisor" type binocular loupes that have been coming out, with LED lights and everything that look kinda cool, but actually my biggest concern is the lighting, as it's often easier to assess something with a fixed light source.

[Kraai]

The working distance is often too great to work properly on a watch.

[HectorLooi]

As a dentist, I have been using binocular loupes for almost 20 years. But it's just unnatural to use it for watch repair. When doing watch repair, I prefer to hunch up with the watch right in front of my nose, with wrist and elbow supports. I find that this gives me the best stability, especially after a cup of coffee.

And binocular loupes have many designs. The 1 in the picture might not be suitable for everyone. It offers adjustable interpupillary distance, but there is no adjustment for declination angle and optical plane height. So unless your face fit the frames perfectly, the loupes might not work for you.

[sjhilbel]

Thank you, everyone! A lot of good info to sift through. Again, I suffer from migraines and single loupes trigger them after a varying times of use. The microscopes are just not in my price realm, and I tend to be as @HectorLooi mentioned "hunch up with the watch right in front of my nose."

[fixermole]

I'm looking for recommendations based on everyone's experience for the optimal loupe magnification/focal length that works the best for pallet jewel or escape wheel lubrication with 9415 grease. Is 10X sufficient or does higher power work better; if the latter is true at what point is the focal length too close for practicality?

I've been using a hand-held 10X triplet lens for that one task but looking for an aplanatic eye loupe, and they're available as 10X, 12X, 14X. Any thoughts and experiences are appreciated.

[Poljot]

2 hours ago, fixermole said:

I'm looking for recommendations based on everyone's experience for the optimal loupe magnification/focal length that works the best for pallet jewel or escape wheel lubrication

What works for me may not work for you - personal preferences.

x10 is fine, anything more - you will have to get closer, less comfortable to work with.

I like using microscope. You may want to read this:

https://meijitechno.com/how-to-change-magnification-on-stereo-microscopes/

select EMZ-5 as an example with x10 eyepieces and note he working distance, etc.

[oldhippy]

It all depends on ones eye sight and if you have a steady hand.