Hi Rochelle,

I do something a bit different and use a linen tester, rather than the conventional lenses sold to geologists. Google ‘Linen tester’, and click on Images. All fold up to about 1” square by 3/8” thick, varies by make.

Linen testers are used by the fabric trade to do thread counts on fabric samples. Mine geologists and oil company geos who log core all day often carry these things.

Linen testers have 2 advantages to conventional hand lenses:

Linen testers have much larger focused fields of view (2.5 cm x 2.5 cm) than conventional lenses. 1 full square inch is in focus at 8X on a reasonably flat rock surface.
The folding square base has good scale bars etched in, usually both in mm and in inches. This functionality is fabulous for describing core!

The only downside is they are a little larger than a conventional hand lens when folded up, and have annoying pointy corners, so if you have one around your neck all day, it needs to be tucked into a shirt pocket so it doesn’t bounce around. Avoid the ones with a glass plate in the foldable base.

Best,

Sam Haines

Earth Observatory of Singapore

From: Tectonics & structural geology discussion list <[log in to unmask]> on behalf of Rochelle Taylor <[log in to unmask]>
Reply-To: Tectonics & structural geology discussion list <[log in to unmask]>
Date: Wednesday, 27 March 2019 at 4:55 PM
To: <[log in to unmask]>
Subject: Re: Field hand lenses

Dear all,

Thank you for your suggestions. It will certainly help in my quest to finding the right hand lens! As you've all mentioned, it's such a crucial piece of kit but when ordering online it is difficult to pick something suitable without trying it so I value the experience of the list members.

And I agree with Umberto. To have such an eminent scientist as Prof. John Dewey offer his advice just reflects the nature and generosity of his generation to impart their knowledge to the next generation of scientists in every aspect. I only hope that I can have 1/millionth of the impact on my own students that the likes of John Dewey has had on us all.

Kind regards,

Rochelle

-----------------------------------------------------------------------------------------

Dr. Rochelle Taylor

From: Tectonics & structural geology discussion list <[log in to unmask]> on behalf of Jason Price <[log in to unmask]>
Sent: 26 March 2019 17:03:02
To: [log in to unmask]
Subject: Re: Field hand lenses

Hi Rochelle,

Iwamoto 20x provides a fantastic field of view. e.g., http://www.ascscientific.com/lens.html

Personally, I use a 10x Hastings triplet and 20x Iwamoto. The Hastings 10x is a decent all-around lens, and the Iwamoto 20x allows me to see a bit more detail. I use them roughly the same amount. However, I know some exploration geologists who only use the Iwamoto 20x because of the detail and clarity you get with it.

In my opinion, don't bother with the Hastings 20x, which has a pathetic field of view.

cheers,

Jason Price

On Mar 26, 2019, at 10:47 AM, Rochelle Taylor <[log in to unmask]> wrote:

Dear list members,

I am looking to purchase a new hand lens for use in the field. I was thinking I would like a dual magnifier but I'm appealing to members of this list for advice on brand, magnification, etc.

Does anyone have any suggestions? So far I have looked at:

BelOMO 10x Triplet Loupe
Ruper 5024 Double Hand Lens

Thank you in advance,

Rochelle

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Dr. Rochelle Taylor

Lecturer in Geology | Department of Geography | Edge Hill University, St Helens Road, Ormskirk, Lancashire, L39 4QP | Office: Geosciences 209 | Phone: 01695 654375 Ex: 6375 | Email: [log in to unmask]

Edge Hill University

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This message is private and confidential. If you have received this message in error, please notify the sender and remove it from your system. Any views or opinions presented are solely those of the author and do not necessarily represent those of Edge Hill or associated companies. Edge Hill University may monitor email traffic data and also the content of email for the purposes of security and business communications during staff absence.

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