OptiVisor questions

[gazer]

Hello all,

Yesterday I got my new pair of Optivisor (Donegan Optical) from Amazon.uk
As you can see in the picture, the lenses (X2.5, 8" focal length) are not symmetrically held in their acrylic frame. However, when I tried to wear them and look at objects, everything was ok.

Therefore, what would be your advise? Ask for replacement? Just leave it and use the visor normally?

Thank you very much!

 

[Steve Edwards]

Blimey! Mine are exactly the same. I've been using them quite happily for the last few years. I say leave it.

 

[gazer]

Blimey! Mine are exactly the same. I've been using them quite happily for the last few years. I say leave it.

Thank you Steve!

 

[John Bowery]

I agree with Steve mine are the same. I guess it is to focus the eyes at 8"?
Cheers
John

 

[gazer]

I agree with Steve mine are the same. I guess it is to focus the eyes at 8"?
Cheers
John

Thank you John

I guess that they should be symmetrical, no matter what length they should focus at. The focal length is dependent on their optical characteristics. I think that x2.5 lenses with greater focal length would be much much more expensive - for example, surgical loops - most surgeons cannot allow themselves such a short working distance, and do pay A LOT more for a pair of x2.5 loops.

But to the point, if it works fine (="ain't broken"), maybe I should not "fix'em"...

Cheers,

Benny

 

[yellowcat]

Here is my 35 years old Optivisor with #5 lens X2.5 times 8 " focal length. I also have the #7 and #10 lens. They all look symmetrical. The inner side of the lens are always thicker than the other side for the optical focal distance and power of the particular lens plate.

#7 lens X 2.75 times 6" focal length

#10 lens X 3.5 times 4" focal length

 

[gazer]

Thank you Yellowcat

In the meanwhile I dropped an email to Donegan Optical.
In mine, if you look carefully, the protrusions are not symmetrical – the right lens protrudes slightly more than the left lens. In yours, as you mentioned, the protrusions are symmetrical. So I don't know if mine are ok...
On the other hand, yesterday I had the first "real" painting session with them, and everything felt great...so I tend to just leave it alone, unless I hear back something else from DO.....

Best,

Benny

 

[yellowcat]

It looks like one of the lens in yours wasn't fit properly in the lens plate and could pops out. I would contact Amazon to get a replacement.

Cheers,

Felix

 

[gazer]

Thank you Felix

 

[gazer]

An update:
I eventually sent the lens to Donegan Optical and got a new replacement lens at no charge. Good service

Benny

 

[Tecumsea]

Hi Felix,

Do you use the 2.75 and 3.5 lenses? Have a 2.5 about 12 years old but struggle a bit with eyes on figures. I have the little loop you can buy to increase magnification but find this too strong/close.
Would the 2.75 or 3.5 help?

Keith

 

[socko47]

POI. With single lenses, the higher the magnification the closer the focal length. Surgeon's magnifiers are actually telescopes, i.e. two lenses. That allows working distances to be set for the surgeon's preference. They also cost $1000.00 or more.

 

[gazer]

POI. With single lenses, the higher the magnification the closer the focal length. Surgeon's magnifiers are actually telescopes, i.e. two lenses. That allows working distances to be set for the surgeon's preference. They also cost $1000.00 or more.

Yes, I have a pair of those that were custom made for me, and the working distance is about 30-40 cm. Indeed, I am reluctant to use a 1500$ piece of equipment outside of the OR...

 

[yellowcat]

Hi Felix,

Do you use the 2.75 and 3.5 lenses? Have a 2.5 about 12 years old but struggle a bit with eyes on figures. I have the little loop you can buy to increase magnification but find this too strong/close.
Would the 2.75 or 3.5 help?

Keith

Hi Keith,
2.75 is my workhorse. I use it all the time. I also have the 3.5 and the loop. I only use the 3.5 once in a while and seldom use the loop.
Hope this help!

Cheers
Felix

 

[Tecumsea]

HI Felix, thanks for your help, I'll buy a 2.75 and see if that helps.

Thanks again,

Keith

 

[Glenn1442]

This is what I use from Quicktest. Lot's of useful info on their site regarding magnification.

 

[Dolf]

I received today my magnifying glasses from China, bought from AliExpress.
Obviously not the original OptiVisor (from Donegan Optical?), but instead a kind of imitation.

They come with 4 lenses, 1.5, 2, 2.5 and 3.5. And the price of course is not even close to the price of the original ones...

But they seem perfectly fine, no defects, and good quality lenses (glass, not plastic...) .
The only kind of critic I'd have is that the Shell seems to be a bit too tight for my head (and I don't have a large one ) . Had to adjust the "wheel of headband tightness" to the maximum possible aperture so they fit just right. Maybe they are done for the average Chinese head size, IDK...

Will start using them later (am now in the process of assembling & painting a 1/350 sailing ship, so it should be a good test), and then will see if it's a practical tool to use for some time, or if it is uncomfortable to have them on my head for larger periods of time.

Cheers!

Dolf

 

[Tecumsea]

It's the equivalent of buying a recast...complete rip off of optivisir, even the same colour, no wonder trump is trying to nail the Chinese. Have they ever invented anything except fireworks and porcelain?

 

[Dolf]

It's a valid opinion of course. I just don't agree with it being "the equivalent of buying a recast"...
It's a copy? Yes indeed. Not a "recast" IMHO...

Well, he can do whatever he wants... but then again... it won't change the fact that China is now the greatest economic world power, and growing by the day... while the others are in full decline...

And yes, China and Chinese culture existed millennia before the Western counterparts. And long, long before Trump and the US... And they invented a whole lot of other things apart from the examples you mention.


Cheers!

Dolf

 

[Tecumsea]

When is a recast not a copy?

I rest my case.

I watch with amusement all of the hysteria on here regarding recasing and the holier than though attitudes-when it comes down to it we all buy what we like when we like or when it suits us financially-your rip off optivisor is just the same but in a different market it is Chinese theft of someones intellectual property.........by the way I don't blame you for buying it, just illustrating a point.

Keith