Camera to take photos of assembled PCBs

[rdl]

It's probably just that the LEDs are overexposed. Try increasing the ambient light or dim the LEDs somehow.

[Ian.M]

That's due to the different colour response of the human eye and the camera sensor.  Also the sensor has far less dynamic range than the eye so bright LEDs may be saturating it. 

If Rdl's quick and easy suggestions don't help, the best option would probably be to take two exposures with the camera on a stand without moving it, one with good lighting and power off to get the whole board and unlit display, and the other with the device on in the dark, with the camera well stopped down to prevent saturation and blooming.   Colour correct the second exposure till the sampled illuminated LED is where you want it in RGB colourspace, threshold it to eliminate (black out) everything except the illuminated LEDs, then overlay them using an 'if brighter' merge mode.

[Brumby]

How do you prevent the red LEDs to look pink-ish?

... ... ...

I know this isn't the best photo equipment and more expensive gear probably provides better results, but is there a way to workaround it with cheaper cameras?

It is a problem for even the most expensive cameras and comes down to one critical factor: dynamic range.

The human eye is amazingly adaptable in dealing with bright and dark areas within a scene.  Photographic equipment far less so.  A typical example I can cite is watching a tennis match as the shadows move across the court as the sun goes down.  When play goes between areas in sun and areas in shade, the TV image doesn't cope with the difference very well and following the ball is a challenge - but if you are sitting in the stands, you don't really notice.  The difference is the primary image sensor - a piece of silicon in a camera or the human eye.

This difference shows up in photos of LEDs where the centre spot of the LED is very high in brightness compared to the surrounding areas and this can push the numeric values extracted from the silicon quite high, heading towards maximums (which, in the extreme, would represent the brightest white) in a scene where the rest of the image would be properly exposed.

There are cameras that have a dual scanning of the sensor - once with high sensitivity and once with lower sensitivity, with electronics to mix the signals in a way to obtain the best total image.  I looked at a Panasonic camera for a project some 20 years ago which had this feature - but I don't know if even it would have been able to render a scene with an LED in it.

Look for cameras that boast High Dynamic Range.  My Samsung Galaxy S5 phone has a HDR setting on the camera.  With it off, a red LED shows up as a pinkish white spot with a red halo.  With it on, the LED shows up as orange with a red halo.

It's been a long time since I was seriously assessing cameras - so I don't know if there is anything on the market that would do this properly ... but I have my doubts.  Seems a bit of post production airbrushing is still the best way to achieve a satisfactory result.

[EEVblog]

I'd go for an older model DSLR camera (even 10Mpixel is fine) that no ones wants with a proper 1:1 macro lens. Find the (used) macro lens first, and then get the cheapest DSLR camera to match.

[jaromir]

My Samsung Galaxy S5 phone has a HDR setting on the camera.  With it off, a red LED shows up as a pinkish white spot with a red halo.  With it on, the LED shows up as orange with a red halo.

Could you, please, take pictures with both settings? I'm really curious how much better results it does provide. There is a plenty of phone camera reviews online, but most of reviewers don't do pictures of red LEDs.

Thank you for detailed explanation.

[TERRA Operative]

If you can output RAW, you can make a colour profile in Photoshop etc with a colour checker card.
You'll need to redo it if the lighting changes, but if you use the same lighting setup each time, you can reuse the profile.

This will help ensure your colour reproduction is as accurate as possible.

[Brumby]

My Samsung Galaxy S5 phone has a HDR setting on the camera.  With it off, a red LED shows up as a pinkish white spot with a red halo.  With it on, the LED shows up as orange with a red halo.

Could you, please, take pictures with both settings? I'm really curious how much better results it does provide. There is a plenty of phone camera reviews online, but most of reviewers don't do pictures of red LEDs.

Thank you for detailed explanation.

Here you go:



(and, no, I don't normally run my hot air at 500º.  I just wanted a second LED in the shot - and one that wasn't blinking.)

[arthurhopkins]

I'm looking for suggestions for a reasonably priced (below $200) camera to take pictures of my assembled project boards. This is mainly for documentation purposes but I may occasionally email them to someone for review purposes. I have an older Kodak DX6490 that does a pretty good job on small boards. But sometimes I can't get good focus. For example, this evening I was trying to shoot a 3 in X 3 in board. When I get far enough away from the board to see the entire board and focus it, I can't see much detail.

Most of my boards are less than 4 in X 4 in but occasionally I will have a 6 in X 6 in board. Is there some type of macro lens I can buy for my Kodak or do I need a different camera? I have a Dino Lite digital microscope that takes excellent photos of small (2 in X 2 in or less) but it can't handle a 3 X 3 board.

I don't know anything about photography, just electronics.

I am using Canon PowerShot ELPH 360 HS, I love it because the 3rd part of the exposure triangle is ISO, which when increased, brings in more light to the sensor. But how about Go Pro HERO5 or Canon 70D.. this post https://passtools.com/best-camera-for-youtube/ make me thing to change my Canon to Go Pro.