[Elphel-support] questions

[Alexandre Poltorak]

Hi,

The only relationship between exposure time and frame-rate is that the last one can be limited by the exposure time. In triggered mode you have to carefully set the exposure time (or limit on maximal exposure time in autoexp), in free-running mode exposure automatically limit the framerate. (again you can set a maximal exposure time)

So maximal exposure time and resolution to get 25 FPS should be 40ms and 1920x1088.

I tried many different cameras and Elphel NC353L perform not so badly in dark environments. 
You can increase exposure to 40ms.
Check that your diaphragm is fully open. 

But if you really want to use the camera in low light solution, I suggest using a monochrome sensor, removing the IR-cut filter and using IR compatible lens. 

Best regards,
Alexandre Poltorak
CTO
 
Office: +41 22 341 3300
Mobile: +41 79 696 4225
Email: a.poltorak at foxel.ch
Web: www.foxel.ch

FOXEL SA
Chemin de Champ-Claude 10
1214 Vernier, Geneva, Switzerland

----- Mail original -----
| De: "201图像所" gmail.com>
| À: "Oleg" list at support.elphel.com>
| Envoyé: Lundi 28 Avril 2014 04:03:02
| Objet: Re: [Elphel-support] questions
| 
| Hi,
| 
| First of all,many thanks for your timing reply.
| 
| I set the frame rate (25fps) in the Free run and check it in the
| camera control interface yesterday.
| 
| Today I set the frame rate(25fps) in the TRIG =4,TRIG_CONDITION
| =0,TRIG_PERIOD = 3840000 ,and check it in the camera control interface
| today,frame rate is 25 fps(green),and I check it in your suggested
| way,it is 25fps, too.
| 
| However,When I set the exposure time to as low as 10ms,the vedio is
| too dark to see in the nature light.Is it that the elphel camera can
| get 25fps in the dark pictures or anything else I must do to adjust ?
| What's the relationship between frame rate and exposure time in the
| elphel camera?
| 
| We hope to receive your favors at early date.Many thanks for your support.
| 
| Rui Song
| 
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