[chbot] More - Contemplating the purchase of a (cheap) inspection microscope

[Volker Kuhlmann]

On Sat 27 Sep 2014 13:22:01 NZST +1200, Mark Atherton wrote:

IMHO you are barking up the wrong tree. If a 3x lupe isn't enough, get a
10-15x one instead. Such thing is essential for any SMD work later than
about 1990. Fits into your storage box easily, portable, cheap.

I've seen an expensive Sony job that had (apart from flash cards of an
obnoxious format) no depth of field, image quality more like looking
through a wet car windscreen without the wipers on, and generally being
more like a pain than a time-saving tool.

Those aliexpress jobs I'd expect are pretty much the same. High
magnification is of no use whatever when all you get is a 1 square
micrometer sharp area hidden somewhere within your field of view. You
could hope technology has improved, but make sure these things are good
for you before handing over $x00. Everyone on aliexpress sells stuff
looking good on the outside...

Is 180x magnification any good for the purpose of SMD soldering? I doubt
it, your viewing area becomes far too small so you start moving things
large distances by micrometers. You can see bad joints at much less than
180x.

> The work plane will be sitting in the hot-air pre-heater about 90mm
> above the deck, so must be able to focus there

Anywhere you like to look.

> Lens needs to survive hot air !

Good luck. Perhaps make yourself a lupe cover. Thin perspex? Glass?
Sceen of an old dumbphone?

> Nervous about HDMI, so stick to USB and VGA interfaces only.

Reconsider and readjust your requirements. VGA is just about dead, and
let's leave it there for good reason.

USB implies proprietary driver rubbish from the manufacturer (Ever heard
of a generic USB microscope device? Like a USB storage device?), so you
won't be plugging the tool into any on-the-road computer just like that,
and certainly not into anything but a 'doze job. Your microscope's
lifetime will be defined by its driver, not its hardware. Your by now
irreplacable (noone sells such small capacities any more may be your
only hope of getting images out of it, if you're lucky enough to own a
card reader still handling those historic esoteric flash cards.

HDMI seems to just work. You can use an adapter for about US$15 from
aliexpress, it works with the RPi.

HTH,

Volker

-- 
Volker Kuhlmann
http://volker.top.geek.nz/	Please do not CC list postings to me.