Soldering Microcope - Barlow lens and lens protection advice

[DTJ]

After much looking around I've just ordered one of these microscopes (despite the horrendous USA --> Australia shipping fee!)

http://www.amscope.com/7x-45x-stereo-binocular-microscope-with-14-pillar-stand.html


The main use will be for soldering and inspecting some 0.5mm pitch PLCCs etc. It has a working distance of 100mm, I'd like to increase this by adding a Barlow lens but have some questions on how all this Barlow lens business works.


1) It seems the microscope has a 48mm lens thread so I'm guessing any 48mm Barlow will fit is this correct?

2) Is there a difference in the width of view with different Barlow lenses?

3) Do I need a 0.5X or a 0.7X Barlow (the scope is 7.5X - 45X Zoom). Is the following correct?
    0.5X will give 3.75X - 22.5X and a working distance of 1/0.5 x 100mm = ~200mm
    0.7X will give 5.25X - 31.5X and a working distance of 1/0.7 x 100mm = ~140mm

4) Is fitting a UV filter in front of the Barlow lens a good idea for protecting the lens against flux and mechanical damage?

5) Do the Barlow lenses usually have a 48 mm thread on the front that I can fit a UV filter to for protecting the lens?


Cheers.

[blacksheeplogic]

100mm is already a lot of working distance. Wait until you have the microscope setup how on the bench you will be using it at, and access your comfortable working height before deciding to add a lens  to increase working distance.

You may find the microscope becomes uncomfortable to use if you increase the working distance which effects working height. Until you have the microscope you can't predict the comfortable working height and that will limit how much working distance you can make use of.

As far as lens shields are concerned, I use a Leica 10446324 with one of mine, and the other I use a Hoya HMC UV(c) lens shield. Neither of them are particularly cheap but they do the job and don't noticeably effect the optics.

[DTJ]

Ooops - I've double posted (something odd happened to my original post so I re-posted).

Proper post is here:

https://www.eevblog.com/forum/projects/soldering-microcope-barlow-lens-and-lens-protection-advice-66380/


Thanks for the feedback Blacksheep. I think you are right, I really need to sit down at the microscope and get a feel for it.
I'll check out the protection lenses you suggested, though I will probably go for something cheap via ebay to save some dollars. I've way overspent on this thing already!