Inspection/Soldering Microscope, how to increase focal length? - Page 1
Forum section: electronics / general

author: cprosser
author_rank: Contributor
timestamp: July 22, 2018, 03:41:36 pm
content: Hi Folks,I had largely stopped doing electronics work because of my neck and upper back. I'm very tall, with most of my height in my torso, and 45 years of hunching to get to everything took a toll on me. I have the back pain much better managed now, so I'd like to get an inspection scope to reduce the need for hunching, and start doing some electronics again. But even a 9" focal length is too short for me (like on this one at Amazon:http://a.co/j4cI9jn).Is it possible to increase the focal length on that? I'm new to investigating microscopes and don't have the terminology down, so I can't quite figure it out from my research.thanks,Chris

author: mcinque
author_rank: Unknown
timestamp: July 22, 2018, 03:46:07 pm
content: For me worked to have an additional 0.5X lens that will decrease of a half the magnification but will greatly increase focal length.

author: helius
author_rank: Super Contributor
timestamp: July 22, 2018, 03:51:49 pm
content: It is possible to increase the working distance if you can attach a Barlow lens of fractional power (such as 0.75x or 0.5x), but this decreases the magnification factor of the microscope.

author: cprosser
author_rank: Contributor
timestamp: July 23, 2018, 11:31:50 pm
content: Great, thanks for the pointer. Barlow Lens is the term of art I needed to keep my search going. Looks like there's nothing available for the cheaper SE-Series scope I was looking at. Hmmm, time to keep searching.

author: duak
author_rank: Super Contributor
timestamp: July 24, 2018, 12:13:55 am
content: Years ago I worked a little bit with lasers, optical systems and inspection microscopes - I know enough to be dangerous. Mitutoyo (among others) make long working distance objectives. These have the same focal length and magnification but the distance to the object is increased over that of a standard objective. They are larger and no doubt more expensive. I have a Mitutoyo 10 X APO, (but no microscope to fit it) and I see the current price is something like $980. It's about 1" in diameter and about 3" long.One term I remember from back then is telecentric. Apparently this can confer a greater working distance as well as other characteristics that are used in machine vision. I don't believe it's necessarily an advantage for your application, however it may be a good idea to be familiar with it.Cheers,

author: rdl
author_rank: Super Contributor
timestamp: July 24, 2018, 02:57:14 pm
content: Only the models which have the round objective lens can use attachments. Here is a one example.https://www.amazon.com/gp/product/B006QN5T5G/Quote from: cprosser on July 23, 2018, 11:31:50 pm

author: ebastler
author_rank: Super Contributor
timestamp: July 24, 2018, 05:10:29 pm
content: I'm afraid that, even with a properly adjusted microscope, your back and neck will experience a lot of strain if you plan to use the microscope as your standard way to look at your work all the time. Being "bolted" to the binoculars for extended periods of time, without much ability to vary your posture, can't be good for you.Have you looked into video microscopes? These would allow you to position your body more naturally, and move around a bit while still watching the monitor. No stereoscopic viewing, however; and it might take a while to get used to not looking down at your hands and soldering iron, but looking "elsewhere".

author: helius
author_rank: Super Contributor
timestamp: July 24, 2018, 08:55:04 pm
content: A Mantis microscope will also allow working at magnified levels without bending your neck.

author: jmelson
author_rank: Super Contributor
timestamp: July 24, 2018, 09:38:47 pm
content: Quote from: cprosser on July 22, 2018, 03:41:36 pmI think what you are talking about is called "working distance", ie. the distance between the object in focus and the bottom of the microscope. Put the microscope at the best height for you, then elevate the work to the right height for the microscope. Inspection microscopes usually have 4-6" working distance (100 - 150 mm). There are surgical microscopes that have insane working distance, like half a meter or more. But, that is way too much for me.Jon