Remote display of Pi Camera

There are two youtube videos, don't know how helpful they might be:

http://www.youtube.com/watch?v=1Egj1TjfHPc

http://www.youtube.com/watch?v=XBaWepyeoq4

Alex Eames described how to stream video to a tablet.

http://raspi.tv/2013/how-to-stream-video-from-your-raspicam-to-your-nexus-7-tablet-using-vlc

I'm sure this can be adapted to stream to a computer.

HTH

-Derek

Derek

Thanks for that.

Streaming video isn't exactly the issue, its seeing the result of raspistill on a remote connection.

Mark

Coder

Thanks for the links.

I've downloaded them for viewing as I have an early start in the morning.

I suspect the preview relies on the hdmi processing, hence its not able to be remoted.

The processed images are, and there are a few ways to either push them across, or grab them from the Pi.

Cheers

Mark

Have you looked at Matthew Manning's video, a few mins in after video flip.  He covers streaming from a Pi to PC using Mplayer and Netcat.  He has put a link for the software in a dropbox.

http://www.youtube.com/watch?v=9vGi376X3PA

The preview is an overlay and is handled entirely by the GPU. It works the same whether you're running a desktop or not. As such it's hard to remote it.

There are other issues, the preview may not be the same as the still image you get - different field of view.  There was supposedly a fix for that, but I don't know if it's available yet.

Streaming video isn't the answer either as that has yet another different field of view.

What I do is to have the Pi save images to an NFS share and view them from that machine, it means you get to see exactly what you'll get.

It's also worth noting that if you ask raspistill for a 1920x1080 image using the -w and -h options it's not simply a crop of the 2592x1944 native resolution and will have yet another different field of view as it scales somewhat the full image to fit your request.

I've not tried the -roi settings yet, but those would seem to crop the raw sensor resolution before scaling what's left to the -w & -h settings.

Anyway, what you really want to try is to grab your still image using the settings you expect to use, then view that on a decent screen elsewhere.

I'll be interested to hear how you get on with your project and what settings you use.  I'm doing some timelapse stuff and have been trying out various combinations, but have come to the conclusion that in daylight I'll be using spot or average metering and iso 100, other metering modes provide darker images of the same scene.  As it's a fixed iris lens, increasing ISO in daylight only seems to give a hint to the GPU to use a faster shutter speed which gives darker images...   At some lower light level it starts to become advantageous to increase the ISO, so I'm adding an ambient light sensor so that I can start to work out when to do that.

With current firmware it seems to be a bit of a guessing game what results you can expect for certain settings, so I just wrote a simple script to cycle through them quickly so I can look at the images and pick what's working.

Selsinork

Thanks for the reply.

As such it's hard to remote it.

I came to that conclusion, but not having played much, and lacking any real Linux skills, needed to check.

What I do is to have the Pi save images to an NFS share and view them from that machine

I figured that was what I was going to need to do.

increasing ISO in daylight only

I read somewhere on the RPi.org site that the ISO doesn't seem to work, and it was stuck on  a list to check.

In the brief check I did (inside) it didin't seem to function like I thought it should ... but I didn't try it in sunlight.

Thanks for the other suggestions.

Mark

Mark Beckett wrote:

 

I read somewhere on the RPi.org site that the ISO doesn't seem to work, and it was stuck on  a list to check.

In the brief check I did (inside) it didin't seem to function like I thought it should ... but I didn't try it in sunlight.

ISO setting was disabled until raspistill 1.2 where it's been enabled again.  You probably need to do the rpi-update dance to get the latest kernel/firmware/apps.

With 1.1 ISO defaulted to 100 which gives fairly good results all round, in 1.2 it defaults to 400, nothing necessarily wrong with that, but the results are quite a bit different

I'm by no means a photography expert, but various things currently don't work in the ways you'd expect even when comparing to a simple point & shoot digital camera..

Maybe I'm being unfair, but it seems that the interactions between the settings are not intuitive and don't always do what you'd expect, or they appear to operate differently depending on what the light level is.  So there's a bit of second guessing around how the settings you provide interact with the algorithms in the firmware.

Keep us posted on how you get on..

You probably need to do the rpi-update

Cheers, I'll do it tonight.

400 ISO is typically grainy, and in the old film days was because the grains in the film had to be larger to be more sensitive.

I noted somewhere that -10 ev was equivalent to -3 stops (each stop is half the light), and this was to allow for 1/2 or 1/3 stop changes.

Now that I've got it to a state of not requiring the screen, I'll move it and try a few pics facing outside, which will allow a few setting tests.

I have a nice bright surface to face it at, so it will at least simulate the snow covered surfaces.

Thanks

Mark

Mark Beckett wrote:

 

400 ISO is typically grainy, and in the old film days was because the grains in the film had to be larger to be more sensitive.

I noted somewhere that -10 ev was equivalent to -3 stops (each stop is half the light), and this was to allow for 1/2 or 1/3 stop changes.

Experimentation suggests that upping the ISO adds noise to the image, in reasonable daylight it doesn't seem to have any other effect and ISO 100 will give a better looking image. If it's overcast it'll probably make the image darker, but that seems mostly due to the faster shutter speed the increased ISO lets the GPU use.

the -ev settings seem to go in perceptible steps of two, add 1 and there's little or no noticeable difference, add two and there is.  Certain combinations don't seem to work together, for example with ISO 800 in reasonably dark conditions, the -ev settings seem to have no effect.  Also if you use -ex off then none of the other settings seem to do much and you get, in daylight, what appears to be the equivalent of average metering, iso 100, -ev 10 and a shutter speed of 1/100.

You're sure to have some interesting times ahead testing different settings to see what works.