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

[Michael Field]

Hi Mark,

I'm not sure if you do the same same sort of stuff as me (0603, down to 
0.5mm pitch on headers), but here is what I do...

I find it easiest to use a Jaycar Illuminated magnifying desk lamp for 
assembly (http://www.jaycar.co.nz/productView.asp?ID=QM3544), then check 
it afterwards with the USB microscope, and nudge things into alignment. 
The intensity of light helps greatly with seeing what I am up to, and 
there is zero lag.

My USB microscope is fine for inspection - have a look at 
http://hamsterworks.co.nz/mediawiki/images/4/4e/Solder_bridge.jpg . That 
image is clipped from a US$64 "SUPEREYES USB 2.0MP 300X Digital 
Microscope" from dx.com. If you try to use it for actually working on 
the board it is pretty poor. You can only use 640x480 or 800x600 before 
it has slow frame rate or the lag gets too bad. You wouldn't want to be 
guiding a hot iron with it when using higher resolutions. It is not so 
much this microscope, but I guess this is because USB 2.0 tops out at 
around 35MB/s, but a full 1080p frames @ 60Hz needs about 450MB/s if it 
isn't compressed or 422. The microscope's three-legged tripod is junk, 
it is light weight so too unstable, but it fits in a case about the size 
of a thick paperback book. and hides out the way. You are more than 
welcome to borrow it if you want.

I am thinking of replacing my microscope with yet another - I have seen 
/ heard OK things about these US$50 microscopes :
http://www.aliexpress.com/item/500x-8LED-HD-2MP-USB-microscope-Aopute-Digital-Microscope-usb-magnifier-Camera-Metal-Stand-Base-pcb/1989562116.html
in particular 
http://www.eevblog.com/2014/01/07/eevblog-566-cheap-usb-microscope-reviews/ 
made is seem OK - 40mm or so of clearance. Have a look around 17min in 
the video.

Mike





On 27/09/2014 12:59 p.m., Mark Atherton wrote:
> Hi All,
>
> Having endured the pain of assembling a small video capture card using 
> 0603 passives, a 64 pin QFN, and some res-packs (4 x 0402), it might 
> be time to get something a little more grown up than a 3x loupe.
>
> A 10x / 20x stereo microscope is to hand, but there isn't much room to 
> maneuver in the inspection area.
>
> Anyway, please take a look below and let me know your thoughts, 
> alternatives, ideas etc.
>
> -mark
>