Magnification: Advice on buying a loupe

[SlowRain]

I want to buy a loupe for looking at my bevel. I don't mind spending a bit of money provided what I get is worth it. Unfortunately, I don't have access to the brands many of you have, so I have to evaluate them myself.

1. I understand clarity is the most important. I assume, all things being equal, that glass would be better than plastic, but I may be wrong here. Has plastic improved to the point that the difference is negligible?

2. How do I test clarity in the store? Will it be obvious, or are there little tricks that can be used to help distinguish which one is actually better?

3. I read that some loupes aren't really the the stated magnification (ie. it says 40x, but really it's much less). Do I just sample a bunch side by side looking at the same object to see which one looks bigger?

Basically, I'm looking for whatever steps or tips would be helpful when evaluating which one to buy. Conversely, what are some indicators of a poor quality loupe?

Thanks.

 

[buca3152]

Buy a few cheap ones. I have 10x,20x,30x and 60x. I use the 10x almost all the time. For me a like a large enough viewing area. I also have a scope that I have used, but I find my face is more accurate in telling me how good the edge is. It helps in the learning stage. Not that I have it all figured out as I still think there is more I have to learn than what I have already learned.

 

[Gamma]

Cheap loupes are usually pretty crappy options.
B&L and Belomo are good options, as are Schneider, Zeiss, and a few others I forget at the moment.

Most of the cheap offerings, like Amazon and eBay show magnifications that are so off it's not funny.
I have a 5 dollar 30x that's more like 3x. The glass is garbage and the FOV is distorted with a lot of abberations.
I've handled a ton of those types - none of them had their magnification correct.

If you can swing the cost of a good Hastings triplet - that's the ticket.

Things that matter -
Actual magnification
Corrected for abberations
Working distance
Diameter of the lens.

I have a 15x B&L triplet - but the pupil is tight. If I remember correctly, the Belamo 15x triplet has a wider opening.
Same basic working distance though. Ive been meaning to get a Belomo because I'm curious.

Most of my observation is done at 4x - I have a few Schneiders for that, but I also have a B&L Hastings 10x that's real nice and the 15x triplet for closer inspection.

I have a scope too - but I hardly ever use it. Most of what I need to see is visible at 4x.

In optics - you will get what you pay for.
Incremental increases in performance will cost exponentially more than expected though.
The thing is - if I am going to be observing that intently, I want to see as clearly as I can.

IMO - a highly corrected optic is worth its weight in gold. For 30-40 bucks, it's an investment.
Until you compare loupes - cheap ones seem like a bargain.

I use loupes every day - have been for a very long time. I see the value in buying a good one but not everyone feels the same way.
It's like any other tool - quality brings value. Cheap - is just cheap.

One more thing - some well made Coddington loupes are less expensive due to their simple design, and can still do a real fine job.
But - the lens has to be done well - a poorly made Coddington will find its way to the trash can quickly in my house.

 

[DJKELLY]

If you really don't mind spending the money, check out the Peak hand held erecting microscopes. They are quality instruments and come in useful magnifications of 25x, 50x and 75x that I know of. I would suggest either of the two lower power scopes. I think they are under a hundred bucks. In use the scope is a tube the size of a small cigar with an angled plexiglass tip that provides focal length. The erecting feature is important to me and the 25x will reveal the smallest chip and basic scratch pattern.

 

[Loner16]

If you really don't mind spending the money, check out the Peak hand held erecting microscopes. They are quality instruments and come in useful magnifications of 25x, 50x and 75x that I know of. I would suggest either of the two lower power scopes. I think they are under a hundred bucks. In use the scope is a tube the size of a small cigar with an angled plexiglass tip that provides focal length. The erecting feature is important to me and the 25x will reveal the smallest chip and basic scratch pattern.

This gent knows his stuff!!

 

[maxman]

I use a 10x Belomo for my pens and other fiddly fussy things.

 

[oakeshott]

Gamma,
Is this the Schneider you're talking about?
http://www.amazon.com/Schneider-4x-Multicoated-Magnifying-Loupe/dp/B0002ER2ZU

 

[Bayamontate]

I use a this children's magnifying glass and like it a lot. Mine is green though.

 

[PapaFish]

I have a cheapo $2 loupe that I got at Harbor Freight. It has two large plastic optics. I basically put the loupe right up to my eye and the focal length is less than an inch. I rest the top of the blade on my nose and focus in on the edge. It has worked very well, and was well worth the $2 I spent on it, and has been a great learning tool. With that said, I have never used a good, or even decent loupe. Doing so may change my perspective drastically .

I also don't own a scope. I have done my best to figure out ways to get by using the tools I have at my current disposal, and have never needed a scope to get things to work. I am afraid that if I get to looking at scopes that I will wind up with a very expensive stereo microscope that I can take pictures with . Who knows... maybe someday.

 

[Steve56]

+1 for what Gamma said.

But there is a way to test. Take an illuminated straight against a dark background or any straight edge very high contrast lighting, and see if you can see a red or blue "edge" at the contrast change. This will be chromatic or color aberration and it can interfere with what you're trying to see.

You can also focus on the edge in the middle of the field, then move the edge off center and see how much it "bows". This is either pincushion or barrel distortion.

You'd like a magnifier that has very little distortion of either kind, but as you can imagine the price goes up rather quickly when you eliminate most aberrations.


Cheers, Steve

 

[Gamma]

Gamma,
Is this the Schneider you're talking about?
http://www.amazon.com/Schneider-4x-Multicoated-Magnifying-Loupe/dp/B0002ER2ZU

Sort of - that's the modern equivalent of one of the two that I have.

The other one is ancient - came off of an old analyzer I think. I keep that one in the kitchen.

I have two others - one is a Toyo 10x for ground-glass inspection, and there's a Fuji 4x that is pretty good too.
The Fuji is nice, not as refined as the Schnieders - but useable.
The Toyo is essentially useless for razor inspections.
I probably have a bunch more hanging around - but that's the bulk of the ones that see use consistently.


Visual inspection can reveal chromatic abberations when they are really obvious.
Other times - the color fringing may not be readily visible.
Depends on conditions, subject matter, etc.
What is usually more pronounced and very obvious are extreme curvature of field and basic distortions.
Not to mention the serious lack of resolution found in most cheap optics.

Every now and then I find an inexpensive option that works well - I have a pop-out illuminated hand magnifier in the bathroom that is really quite good. Even though it was a give-away perk - I know who made it and I can tell you that their product lines are anything but consistent in this regard. Somedays you get a good one, other days not so much.

 

[Fuzzy Chops]

Hi Denny, good to see you here.

 

[DJKELLY]

Thx, Fuzz. You too, WD.

 

[ouch]

I use a 10x Belomo for my pens and other fiddly fussy things.

I bought one of those for ten clams and it works great. A higher magnification just makes it harder to use.

 

[SlowRain]

Thanks, guys. I ended up buying a 25x Yue Tai loupe with a light for 1800TWD from a market here. That was more than I wanted to pay, but it was noticeably better than the 10x which had some of the problems listed above. The case on this one is a fairly cheap plastic, but the lens didn't seem to exhibit any obvious problems to my untrained eye. I looked at a pair of scissors that the vendor had as a test. Now I just have to learn what it is I'm looking for.

http://yuetai.com.tw/

 

[chuckr9]

I use a 10x Belomo for my pens and other fiddly fussy things.

+1 this is my go to loupe, even though I have many others/types

 

[shakin_jake]

Thanks, guys. I ended up buying a 25x Yue Tai loupe with a light for 1800TWD from a market here. That was more than I wanted to pay, but it was noticeably better than the 10x which had some of the problems listed above. The case on this one is a fairly cheap plastic, but the lens didn't seem to exhibit any obvious problems to my untrained eye. I looked at a pair of scissors that the vendor had as a test. Now I just have to learn what it is I'm looking for.

http://yuetai.com.tw/

~~~~Hi S!...nice going, the loupe you bought...I'm sure it will serve you well

As to learning what to look for...speaking strictly for myself, how I use my loupe, and that said, I'm sure others have better and different ideas on how they use theirs=....but the way I use mine, and I'm mentioning this for others, new to honing, and straight razor shaving, especially new to straight razor shaving...even if you don't hone (though you should, too simple not too=...anyways, anyone that picks up a straight razor and uses it to shave with needs to inspect the edge before shaving. I've heard from a friend who frequents this site, I was told "so and so never uses a loupe" Fine, for them. Me?, I want to see what the edge I'm about to put up to my face looks like

So you may ask, "what do you want to see on the edge Jake?" Well, how about checking the edge to see if there is any micro chipping present. I wonder how many straight razor shavers have shaved with micro chipped edges w/o realizing it? <that's a rhetorical question> For those that haven't, or have and they didn't realize the edge had micro chips in the fin (the intersection of the two bevels)...it can and will make you bleed. Yeah, there's a good reason for you to use your loupe S....to check for micro chipping, before shaving

When I have a new to me blade, usually something that came from the wild, but it can be a new blade too, I like to use my loupe (here it is)-

to see what both bevels look like, where they start, where they end, on each side of the blade

If I'm going to correct the bevels and let's say I use my Chosera 1 K because it is fast, I'll do a few passes on each side of the blade (each bevel) then look at the bevels to see what the pass on the hone did to them...so there's another use, or a way for you to use your new to you loupe S. At least that's how I use mine when I'm about to put an edge on a blade...I like to take the edge to the hone I'm using for bevel correction, do a few passes on each bevel then inspect to see how the bevels are hitting on the hone

then of course, I'll monitor progress on the hone using the loupe. Nothing worse (IMO) than to mindlessly hone/sharpen an edge (do some laps) and not keep track of your progress. Not that the goal is to put as little wear as possible on the bevels, though that is worthy...it seems to me it makes little sense to hone past the point you want to accomplish, but then again, this is another reason I perform the arm hair test when correcting bevels. If I'm doing sets of 15 laps per side (reps) with the goal to correct the bevels, then why do more reps than is necessary?...the arm hair test is one way but if you are using a loupe, you can also see what is happening to the bevels as well

Everyone I know has their own particular way of honing an edge and sure, some wont use a loupe while honing...but I'm not one of them. I like to look up and down the entire bevel to keep track of the changes while honing, when I want to. Sometimes I'll take an edge through it's paces, w/o using the loupe, say after I see where I'm at during bevel correction. If all is going swimmingly, the loupe isn't getting much use, but how often does that happen<that's a rhetorical question>

I'd say this S....next blade you get from the wild, take a good look at the bevels before you put it to your bevel correcting hone. For me, that's either my Cretan or my Chosera 1 K. Using your loupe...watch progress during bevel correction, and keep an eye on the bevels all through the rest of the honing progression. I'm sure you'll find utility using your new loupe

FWIW, the pic of my loupe...it is nothing fancy...just a 10 X (power) loupe...10 X 21mm, glass, metal case...does the job well enough for me



Best,


Jake
Reddick Fla.

 

[SlowRain]

Thanks, Jake.

I just received my La Pyrenees, which I'm going to try to use for bevel work. I'll be paying close attention with my loupe to note the changes.

 

[Doc226]

I have a cheap one from Amazon
http://www.amazon.com/30X-AND-60X-L...UTF8&qid=1381844894&sr=8-2&keywords=60x+loupe

It is cheap but it works.

I also have a nice B&L one but does not have its own light source, makes it harder to use.

 

[SlowRain]

Here's what mine looks like with the legs flipped out.