What to buy for pictures of my scope's screen?

[atferrari]

My cheap digital camera has no manual focus adjustment.

Trying to take pictures or record short videos of what is going on my scope's screen has failed up to now. Always out of focus.

Asking for help on this, I was advised to use a webcam (with focus manual control) or even a surveillance camera.

I have no experience at all with that.

After finding out the high prices of the cameras with focus manual adjustment I am looking for a cheap solution still allowing sharp pictures/videos.

Any reasonable concrete solution?

Gracias.

 

[jpanhalt]

I use an ancient Nikon Cool Pix camera 3.2 MP and equally outdated 96 MB CF card. It has optical zoom and works well. That is all I use it for, and it is quite superior to my much newer Canon for photographing the LCD screen, because it has genuine optical zoom. It is also pretty good at capturing photomicrographs shot through a regular 10X ocular.

I suspect on the used market today, they are quite cheap. (I bought my new a long time ago, and it is not for sale.)

Here is an example from earlier this year: https://www.electro-tech-online.com/threads/serial-communication-protocols.118067/#post968951

John

 

[squishy36]

I had to take hundreds of pictures from my HP digital scope a number of years ago and I just used my Casio pocket camera. They can be found for around $100 and worked well for my needs, once I worked out the requisite settings. I built a simple shroud from some sheet plastic that worked like the old scope cameras to block extraneous light.

A few years ago a company loaned me one of their digital scopes for some consulting work I did for them and they've never wanted it back, so I just use that now. It saves the waveform to a USB thumbdrive and is much more handy than taking pictures.

 

[atferrari]

Sorry, there is a graticule in way...

Sorry. I failed to explain the actual problem: my old scope has a graticule some 10 to 15 mm ahead of the screen what makes the focus incorrect vis a vis where the actual image is.

Sorry for not explaining that!

 

[jpanhalt]

That is where a good lens to give you depth of field is a must. There is no way around that; it is physics.

John

 

[atferrari]

What about the webcam idea then?

Yes John. That is why I posted.

Any help with the webcam part of my question?

I do not want to spend money in the wrong thing.

Gracias.

 

[alec_t]

It's counter-intuitive, but have you tried holding the camera further away from the screen? The graticule and the trace will then be more nearly the same distance from the lens and both should be in focus. Of course, you'll have to digitally enlarge the image and that will introduce some fuzziness/pixellation, but it may be acceptable.

 

[jpanhalt]

I don't know anything webcams and very little about surveillance cameras. My cheap surveillance camera is almost a pin-hole camera. That should give pretty good depth of field. The problem I would see with any sort of video camera that raster scans will the strobe artifact. My Nikon will give limited-resolution motion by taking individual digital flashes.

My TEK 2235 has a graticule, but I don't think it is anywhere near 10 to 15 mm from the CRT. Based on my experience with the Tek 210 images that are cropped before posting, the instrument frame (not shown and at least 10 mm from the LCD image) is in pretty good focus in the whole image. I'd be willing to make a test with the 2235, if you think that would apply to your situation.

John

 

[picbits]

I had success adapting a cheap webcam for close up work once. I removed the lense, moved it a bit further from the CCD, refocused and off we went.

If you don't mind messing around with your old camera, its worth having a play.

 

[squishy36]

The standard answer for the problem with the graticule is to stop the lens down to increase the depth of field. Of course, this only works so far; it's easy with manual cameras but can be hard or impossible with the modern cameras that have been dumbed down. Another thought is to open up the case and remove the graticule. You could take a picture of it, then use a script to add it digitally to photos without the graticule later if it's important to you (I've done similar things before and I can tell you how to do it in python using the Python Imaging Library).

 

[Mr RB]

It's counter-intuitive, but have you tried holding the camera further away from the screen? The graticule and the trace will then be more nearly the same distance from the lens and both should be in focus. Of course, you'll have to digitally enlarge the image and that will introduce some fuzziness/pixellation, but it may be acceptable.

Yep that's what I do, turn macro OFF and get the camera about 2.5 to 3 feet from the screen. Both macro off and the extra distance make the focus less critical. Since most cameras have a gazillion megapixels now the image size doesn't matter, on a photo of 3000 pixels across the scope screen will still be 500 to 800 pixels wide, plenty of detail.

 

[Bob Scott]

No macro function? I found that simply holding a good quality magnifying glass in front of the lens helps a cheap camera fucus properly to up-close photographs. Hold the magnifier right up as close as possible to the lens.
It sure helps to be able to see the actual image like a SLR or digital camera.

Holding a camera right against the objective lens works when taking pictures from a microscope too.