What digital microscope to use?

[Jane]

We need to solder FPC( flexible printed circuit) that  have ONLY about 0.1mm pitch between the  pads. Because of a such small pitch we need a proper alignment against traces on PCB so that we can  make a proper alignment.
Can anyone recommend a magnifier/microscope to use?
Is a digital microscope suitable also?

What zoom magnifier a such microscope should have?



Thanks for your suggestions.

[lapm]

Our very own Dave Jones has done review of few cheap usb microscopes for soldering...

[Cliff Matthews]

For those "on the cheap" an old Logitech QCam can work if you take it apart and unscrew the lens as far as it will go. Glue the lens in the desired magnify spot and find a way to mount on an old goose-neck.
It even auto-adjusts for low light. Use VLC player in Windows and "open capture device" on the main menu. My Windows 10 recognizes it long after Logitech has stopped supporting it.

[Cliff Matthews]

A bit more info - I have two old Logitech scrappers used for close-ups. An old QC 640x480 (manual screw focus lens), and a C270 1280x720 with lens from a scrapped Hitachi camera on a 10 meter USB cable. Presently, I use the QC because the lens doesn't barrel the image so much, but I hope to find another lens for the better model. Here's some pics of the taped-up twin webcams - reduce, reuse, re-cycle!

[Psi]

personally i wouldn't bother with anything USB.
The lag will be terrible unless you run at a horrible resolution.

Maybe a USB3 device would be better but you are taking a risk that it actually uses the USB3 bandwidth. (It maybe a crappy USB2 device that talks over USB3)

Something with HDMI output is what you want, sadly there aren't many options for cheap.

[Cliff Matthews]

personally i wouldn't bother with anything USB.
The lag will be terrible unless you run at a horrible resolution.

Maybe a USB3 device would be better but you are taking a risk that it actually uses the USB3 bandwidth. (It maybe a crappy USB2 device that talks over USB3)

Something with HDMI output is what you want, sadly there aren't many options for cheap.

I get 60fps on USB 2 from the c270 and no lag. But then again we'd be talking two audiences here and two distinct budgets.

I'm semi-retired and diabetes has ruined my eyes enough that I seek to use what I can at a hobbyist level. When I find the right lens for the c270, I'll mount it on a heavy duty goose-neck I've kept and make a dimmer-ring of 1-watt LED's to bring in light from all angles...

[Psi]

There's no reason why you cant have a USB2 cam that is smooth, it just needs to compress the data well before sending over usb. H264 etc

Sadly i've never seen one that does this.

Are you sure you get true 60fps.  Try moving an object from side to side fast at 720p or 1080p 30/60fps. Does it all blur together?
If so the device is not really 60fps but something like 10fps with some math applied in the windows driver that fakes 60fps using temporal interpolation.
Another way they sometimes do it, is to use a mpg1 codec on the device. The data rate is still too high for 60fps HD so they apply the temporal smoothing before feeding it into the mpg codec which makes the codec much more efficient at compression.

The side effect is always the same, its nice and smooth under 640x480 30fps but at any higher resolutions and it starts to blur together and is very obvious with any movement.

[Cliff Matthews]

There's no reason why you cant have a USB2 cam that is smooth, it just needs to compress the data well before sending over usb. H264 etc

Sadly i've never seen one that does this.

Good to know. That has to be the reason the C270 gets quite warm after a few minutes. I can't wait to find a good close-up lens then...

[Cliff Matthews]

There's no reason why you cant have a USB2 cam that is smooth, it just needs to compress the data well before sending over usb. H264 etc

Sadly i've never seen one that does this.

Are you sure you get true 60fps.  Try moving an object from side to side fast at 720p or 1080p 30/60fps. Does it all blur together?
If so the device is not really 60fps but something like 10fps with some math applied in the windows driver that fakes 60fps using temporal interpolation.
Another way they sometimes do it, is to use a mpg1 codec on the device. The data rate is still too high for 60fps HD so they apply the temporal smoothing before feeding it into the mpg codec which makes the codec much more efficient at compression.

The side effect is always the same, its nice and smooth under 640x480 30fps but at any higher resolutions and it starts to blur together and is very obvious with any movement.

Lag confirmed at high res. Rats..! I tried moving a soldering iron in precision steps along a UPC bar only looking at the screen. It wasn't easy!
About 250ms was enough to throw my co-ordination out the window. 

[Cliff Matthews]

I wasn't going to open mine, but for the sake of those who have a c270, the lens can be adjusted to get focus at 1 inch as shown here:

Still, as PSI notes, the lag between what you're doing and what you see, is only good for pictures and not live work.
I'm currently looking at direct screen dump (on VLC if possible) by getting access to raw bayer data from older Logitech devices.
http://web.archive.org/web/20111006053007/http://www.quickcamteam.net/devices/

[Cliff Matthews]

FWIW, I made a small mod on the C270 after finding the lens inside was adjustable. It took just a few minutes to hone out the front fascia and glue-in a knurled adjustment extension. No functionality was lost, but now I can use this right down to 15cm's. The beauty of that CCD caught my attention (always nice to smell the roses along the way...)

[f5r5e5d]

http://www.gigastone.com/EN/product/c/2/n/39 no knowledge beyond the ad - "no latency", up to 90 fps @ VGA

[kentroverman]

I think that the best thing to do is treat yourself to a optical stereo microscope. Amscope make a good scope for about 180 pounds a lot of money but in the long run you wont regret it. To get a good digital scope will cost that amount and it still wont be that good. You can get a good second hand scope on ebay.

[Cliff Matthews]

I think that the best thing to do is treat yourself to a optical stereo microscope. Amscope make a good scope for about 180 pounds a lot of money but in the long run you wont regret it. To get a good digital scope will cost that amount and it still wont be that good. You can get a good second hand scope on ebay.

After PSI's comment, and my self challenge on co-ordination vs latency (I thought 250ms was low), I still can't come around to spend that kind of coin. Another apparatus sitting around is what I don't need when space is already at a premium. But if I can find an app to pull USB live bayer data from any one of the 4 Logitech cameras I have, I'll go half-way and buy dental binocular loupes for $40 on ebay.
http://www.amazon.com/Binocular-Working-Distance-Surgical-Topdental/dp/B00H3ZEKIS

This is $45 with a dimmer and light: http://www.ebay.com/itm/3-5x-420-Dental-Surgical-Binocular-Loupes-LED-Dental-Head-Light-lamp-silver-bs-/140907340844
Working distance seems good, and depth of field should be fine to wrap my through-hole head around SMT soldering and other closeup work.
Bad eyes and floaters are said to be part of getting old, but it sucks. Any comment by those who have used these? Will they frustrate, or should I break open the piggy bank?

[Tac Eht Xilef]

There's no reason why you cant have a USB2 cam that is smooth, it just needs to compress the data well before sending over usb. H264 etc

Sadly i've never seen one that does this.

That's because anything like H.264 etc that uses inter-frame redundancy is guaranteed to increase lag by at least (1/framerate) * [# of frames in compression group] + compression overhead.

So for 30fps, and assuming 3 frames/group (H.264 will go down to 1; a practical absolute minimum is 3~5; numbers in the 100's aren't unusual for streaming cameras), that's 100ms+encoding overhead right off the bat.

In other words, if your aim is low-latency you really don't want to use H.264...

[Cliff Matthews]

In other words, if your aim is low-latency you really don't want to use H.264...

I saw Dave using AMcap in one of his videos, so I thought I'd try it. It works! My C270 (modded above) is USB 2.0 which can push around 42 megabytes per second. To avoid any contention, I plugged it into a USB 3.0 port and got at 720p at at least 30 fps. I did a simple coordination test soldering by a 22" flat screen alone. Yes, these 720p cameras sell for under $20 on ebay.

Theory: 42,000,000 / (1280 x 720) per frame = 45.57 fps
Rough video:

[Tac Eht Xilef]

Framerate != latency.

[fivefish]

I bought an NTSC camera on eBay, and hooked it up to a small TV broadcast monitor.  No computer needed.  For the camera stand, I used a hot-air gun holder. I can raise and lower the arm where the camera is secured, adjust focus ring, etc.

I just use this for inspection after SMD reflow. I tried working/soldering looking only at the monitor and I find it hard since I don't have any depth perception. But works great as an inspection tool.

[Cliff Matthews]

Nice, I have 3 a bit smaller but as shown, they'd need a balun to connect to my shop 22" LCD TV composite jack.
Any quick suggestions on making one?

[Cliff Matthews]

Those NTSC cams were part of this package (the baluns were inside the switcher unit and if I recall standard RJ45 cables would work)
http://www.amazon.com/Inetcam-Vts-8500-Stream-Cameras-Switcher/dp/B0000514T7/ref=cm_cr_pr_product_top

Unfortunately, the switcher unit was never supplied, so power, pinout's and balun magic I'll have to figure out.

[SeanB]

No balun needed, just wire red/orange to 5V or 12V depending on the camera ( try 5V first), black to common and yellow to the composite lead, screen connected to black. White would be the audio output. Pretty standard camera wiring on the board

[Cliff Matthews]

No balun needed, just wire red/orange to 5V or 12V depending on the camera ( try 5V first), black to common and yellow to the composite lead, screen connected to black. White would be the audio output. Pretty standard camera wiring on the board

Thanks Sean, it started to work at 10v so I tested with 12v and wired an RJ-45 - the image is sharp with nice color.. and right down to 5mm. I was not happy the folks who setup the focus for these units used a pointed set screw damaging the outside of the metal lens barrel. I tried repairing the damaged threads a bit, but screwing it in again only made it worse so I'll know better for the other 2 units. As you can see below the CCD housing is plastic so I'm might re-thread it.

[KL27x]

I think that the best thing to do is treat yourself to a optical stereo microscope. Amscope make a good scope for about 180 pounds a lot of money but in the long run you wont regret it. To get a good digital scope will cost that amount and it still wont be that good. You can get a good second hand scope on ebay.

I wouldn't go that far. The problem is once you have used one, you won't want to go back. That doesn't mean you can't get the result you need a lot cheaper in dollars and desk space. Too late for me, though. I have a 75 lb monstrosity permanently taking up space on my bench, now. And I used to get things done just fine without it. I'm just spoiled, is all.

[Cliff Matthews]

I think that the best thing to do is treat yourself to a optical stereo microscope. Amscope make a good scope for about 180 pounds a lot of money but in the long run you wont regret it. To get a good digital scope will cost that amount and it still wont be that good. You can get a good second hand scope on ebay.

I wouldn't go that far. The problem is once you have used one, you won't want to go back. That doesn't mean you can't get the result you need a lot cheaper in dollars and desk space. Too late for me, though. I have a 75 lb monstrosity permanently taking up space on my bench, now. And I used to get things done just fine without it. I'm just spoiled, is all.

75 pounds? Must be like this: http://www.ebay.com/itm/7X-90X-Trinocular-Stereo-Boom-Zoom-Microscope-Fluorescent-Light-/400429169625
Now I see why you're so pampered. Interesting how they get depth perception and why even a smaller one weighs so much: