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by ethanol100
Thu Nov 14, 2019 5:59 pm
Forum: Camera board
Topic: Creating a RPI-assisted microscope
Replies: 75
Views: 13501

Re: Creating a RPI-assisted microscope

You could have a look at CD/DVD/BluRay(from Wikipedia): https://upload.wikimedia.org/wikipedia/commons/thumb/a/ad/Comparison_CD_DVD_HDDVD_BD.svg/2880px-Comparison_CD_DVD_HDDVD_BD.svg.png Looking at the distance between lines you end up with 1.6um for CD, 0.74um for DVD and 0.32um for Blu-rays. It co...
by ethanol100
Wed Nov 06, 2019 2:04 pm
Forum: Camera board
Topic: Camera module and H264 doubts
Replies: 5
Views: 712

Re: Camera module and H264 doubts

The camera sends raw 10bit Bayer data down the CSI cable. The ISP(hardware inside the GPU) of the Raspberry Pi will receive this raw data and will do quite some processing(debayering, denoising,...). It ends up with a 8bit representation of the image(usually YUV) which then can be encoded in real-ti...
by ethanol100
Fri Sep 27, 2019 4:44 pm
Forum: Camera board
Topic: Frame is late?
Replies: 9
Views: 452

Re: Frame is late?

You will need to start the camera , which will take some seconds. This starts in video mode, and then it is switched to image mode, discarding about 2-3 frames. For the first frame the burst mode does not work as expected and you will lose again about 2-3 frame. In the following frames they should b...
by ethanol100
Thu Sep 26, 2019 10:26 pm
Forum: Camera board
Topic: Frame is late?
Replies: 9
Views: 452

Re: Frame is late?

I think you can try to set the time lapse parameter to 0 which means just take them as fast as you can(If I remember correctly...). Your issue is that you request an image in an interval of the time of its exposure, but you need to encode and save it, too. This will take always a bit longer then exp...
by ethanol100
Mon Jul 22, 2019 6:50 pm
Forum: Camera board
Topic: picamera - Actual framerate of V2 module is lower than expected
Replies: 11
Views: 690

Re: picamera - Actual framerate of V2 module is lower than expected

I vaguely recall the maximum reported framerates involved some kind of overclocking. See for example https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=145815#p960789 Correct! This is a good example were the Pi4 slightly higher clock comes in handy. I tested recording 5 min to /dev/shm using r...
by ethanol100
Mon Jul 22, 2019 6:26 am
Forum: Camera board
Topic: picamera - Actual framerate of V2 module is lower than expected
Replies: 11
Views: 690

Re: picamera - Actual framerate of V2 module is lower than expected

From your linked documentation: Note These are not the set of possible output resolutions or framerates. These are merely the set of resolutions and framerates that the sensor can output directly to the GPU. The GPU’s ISP block will resize to any requested resolution (within reason). Read on for det...
by ethanol100
Fri Mar 15, 2019 2:36 pm
Forum: Camera board
Topic: Omnivision OV5647
Replies: 3
Views: 581

Re: Omnivision OV5647

I don't recognise this as standard Pi camera board software. What is this and where did you get it from? This is the first line of raspistill -v. It seems to be a rather old version of raspistill, it changed from numbers to commit ideas some weeks ago and was previously at "v1.3.11". Apparently, th...
by ethanol100
Fri Mar 01, 2019 9:11 pm
Forum: Camera board
Topic: Raspistill has gone haywire
Replies: 32
Views: 2498

Re: Raspistill has gone haywire

The fix is not there yet. You will need to change line 292 in file host_applications/linux/apps/raspicam/RaspiHelpers.c to

Code: Select all

us = spec.tv_sec * 1000000ULL;
Afterwards you need to run the "./buildme" again.
by ethanol100
Fri Mar 01, 2019 5:53 pm
Forum: Camera board
Topic: Raspistill has gone haywire
Replies: 32
Views: 2498

Re: Raspistill has gone haywire

jamesh wrote:
Fri Mar 01, 2019 12:54 pm
I found it died within 1hr on my tests, so if the fix lasts much longer that a good sign.
Yes, it has run now for more than 5 and did not fail. The fix looks good to me.
by ethanol100
Fri Mar 01, 2019 12:14 pm
Forum: Camera board
Topic: Raspistill has gone haywire
Replies: 32
Views: 2498

Re: Raspistill has gone haywire

Yes, I think it will fix the issue. I'm currently running a long time test with only this single line changed, previously I changed other lines, too. There are still some places, where overflows could occur. There is the integer division to get "current_time" and the calculation of the skipped frame...
by ethanol100
Thu Feb 28, 2019 9:35 pm
Forum: Camera board
Topic: Raspistill has gone haywire
Replies: 32
Views: 2498

Re: Raspistill has gone haywire

Yes, this was my guess, too. Running since then without issue. I just used LL instead of ULL.
by ethanol100
Thu Feb 28, 2019 8:00 pm
Forum: Camera board
Topic: Raspistill has gone haywire
Replies: 32
Views: 2498

Re: Raspistill has gone haywire

The time returned from get_microseconds64() is wrong... I print out clock which is the return value from get_microseconds64(), after a while: ... Clock: 2146226864ms NextFrameMS: 2147742ms thisDelay: 1516ms Clock: 18446744071562788642ms NextFrameMS: 2149742ms thisDelay: -18446744069413046ms nskip:20...
by ethanol100
Thu Feb 28, 2019 8:14 am
Forum: Camera board
Topic: Raspistill has gone haywire
Replies: 32
Views: 2498

Re: Raspistill has gone haywire

That is strange, even when the time got changed, this should not happen, the next frame is calculated by frame+nskip and nskip is calculated using "int nskip = 1 + (-this_delay_ms)/state->timelapse;" where this_delay_ms is previously tested to be negative, nskip should always be positive. Can using ...
by ethanol100
Tue Feb 26, 2019 8:50 am
Forum: Camera board
Topic: Is there any photo/video of flying rifle bullet done with v2 camera?
Replies: 25
Views: 4033

Re: Is there any photo/video of flying rifle bullet done with v2 camera?

How fast can those flash LEDs on camera phones go? White LEDs won't work because of the phosphor which will glow for a longer time. You can use R,G and B LEDs. But the required current and number of LEDs to get a good lighting is insane. It would be possible, though. I now understand how the "Air S...
by ethanol100
Mon Feb 25, 2019 5:50 pm
Forum: Camera board
Topic: Is there any photo/video of flying rifle bullet done with v2 camera?
Replies: 25
Views: 4033

Re: Is there any photo/video of flying rifle bullet done with v2 camera?

Yes, its boring, but it is the reason why you can't easily capture bullets with consumer grade cameras. Most cameras start with a minimum exposure time of 1µs, even the normal high speed cameras you can get in Europe. The Phantom cameras are limited to 1µs if you want to import them.
by ethanol100
Mon Feb 25, 2019 10:48 am
Forum: Camera board
Topic: Is there any photo/video of flying rifle bullet done with v2 camera?
Replies: 25
Views: 4033

Re: Is there any photo/video of flying rifle bullet done with v2 camera?

If you look at the "COMMISSION DELEGATED REGULATION (EU) 2018/1922 for "Community regime for the control of exports, transfer, brokering and transit of dual-use items" , you will find the following paragraph 6A003.a.5 6A003 Cameras, systems or equipment, and components therefor, as follows: a. Instr...
by ethanol100
Fri Feb 22, 2019 5:16 pm
Forum: Camera board
Topic: Faster image captures using picamera
Replies: 1
Views: 589

Re: Faster image captures using picamera

Looking at picamera documentation it says: The use_video_port parameter controls whether the camera’s image or video port is used to capture images. It defaults to False which means that the camera’s image port is used. This port is slow but produces better quality pictures. If you need rapid captur...
by ethanol100
Wed Jan 30, 2019 4:48 pm
Forum: Camera board
Topic: Minimum Object Distance (M.O.D.) of the Arducam v2.1 with Raspberry V2 cameras and suggestions on lenses
Replies: 4
Views: 547

Re: Minimum Object Distance (M.O.D.) of the Arducam v2.1 with Raspberry V2 cameras and suggestions on lenses

I think the challenging part is the Depth of Field. If you want to to have something focused at 6cm and at 20cm at the same time, this will most probably not work. If you just want to focus on a specific distance, it will be fine. Taking the standard v2 camera and focusing to an object 6 cm away, yo...
by ethanol100
Mon Jan 28, 2019 4:08 pm
Forum: Camera board
Topic: arecord through ffmpeg possible?
Replies: 7
Views: 780

Re: arecord through ffmpeg possible?

bcm2835-v4l2. It is an small L and not a 1. The module should be available on your pi zero, too. It is short for "video for linux two".
by ethanol100
Sun Jan 27, 2019 2:51 pm
Forum: Camera board
Topic: arecord through ffmpeg possible?
Replies: 7
Views: 780

Re: arecord through ffmpeg possible?

You can try to use the v4l2 driver instead of raspivid. You could do one time: sudo modprobe bcm2835-v4l2 Then you can then use the video4linux2 input in ffmpeg: v4l2-ctl --set-ctrl video_bitrate=17000000 ffmpeg -f alsa -i hw:1 -itsoffset 00:00:00 -f video4linux2 -input_format h264 -video_size 1920x...
by ethanol100
Fri Jan 25, 2019 7:07 pm
Forum: Camera board
Topic: Raspiraw images over or under exposed
Replies: 19
Views: 1573

Re: Raspiraw images over or under exposed

I gave raspiraw a try and I find it difficult to get good looking images, too. Even for the right exposure, the final images looked washed out and the white balance was off. I tried out some parameter to raspiraw and dcraw and in the end I got reasonable results. You can start using raspivid with th...
by ethanol100
Wed Jan 23, 2019 10:05 pm
Forum: Camera board
Topic: Raspiraw images over or under exposed
Replies: 19
Views: 1573

Re: Raspiraw images over or under exposed

But Hermann's posts usually are for high framerates and thus for shorter exposures? Did you try any of the other resolutions/framerates?
by ethanol100
Wed Jan 23, 2019 9:20 pm
Forum: Camera board
Topic: Discoloration in images
Replies: 7
Views: 694

Re: Discoloration in images

Are you running out of disk space? If you write an image and the file gets truncated you could end up with something like this.
Is this the image saved directly or the processed one?

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