About ISO on video mode

Discussion in 'SJ7 Star' started by MauriceWhite, Feb 22, 2018.

  1. MauriceWhite

    MauriceWhite New Member

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    I will receive soon my new SJ7 star and I would ask you about ISO on video mode.

    Is it possible to change ISO values on video mode?

    Has anyone tried to record on different ISO values to compare if the video is more or less noisy?

    Thank you
     
  2. corallino

    corallino New Member

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    [QUOTE = "MauriceWhite, post: 5494, membro: 185"] Riceverò presto la mia nuova stella SJ7 e vorrei chiederti di ISO in modalità video.

    È possibile modificare i valori ISO in modalità video?

    Qualcuno ha provato a registrare su valori ISO diversi per confrontare se il video è più o meno rumoroso?

    Grazie [/ QUOTE]
    Cerrtamente, è possibile modificare i valori ISO in modalità video, ma c'è un problema che al momento ho evidenziato nello staff di assistenza di Sjcam. Il cambiamento dei valori ISO è stato attivato durante le riprese video alla luce del sole mentre erano vuoti durante le riprese notturne.
    Allego una copia stampata della nota inviata al supporto SJCAM: http://support.sjcam.com/support/discussions/topics/9000032466/page/last#post-9000121098
     

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  3. MauriceWhite

    MauriceWhite New Member

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    "Il cambiamento dei valori ISO è stato attivato durante le riprese video alla luce del sole mentre erano vuoti durante le riprese notturne"
    Sorry but, can you explain detailed this, I don't understand what you mean.
    When light is low you cannot change ISO value??
     
  4. corallino

    corallino New Member

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    Exactly, when you shoot at night the ISO values do not respond and the same is true for EV.
    See this video by Ferdi A. chief administrator of a group to whom I presented the problem. :
     
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  5. Sulev Svilponis

    Sulev Svilponis Elite

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    Do they respond at daylight?

    Generally, when there is too dark, then EV adjustment can't help to make videos/photos any brighter, because in the Full Auto Mode a camera is already using it's maximum settings (slowest possible shutter speed, most sensitive ISO speed and maximum aperture combination). If you fixed some of those 3 parameters manually (or they are limited by the lens or camera model, for instance fixed aperture lenses), then, again, EV adjustment can't change that parameter. You can set EV offset only in the direction, where (at least some of) those parameters are not reached their limits.

    I assume, that your camera has fixed aperture lens, so it is only possible to adjust shutter speed and ISO. If you fix the ISO manually, then the Shutter speed remains as the only option for adjusting video brightness. But the Shutter speed is heavily dependent on the frame rate. If you set 60fps, then the shutter speed can't be slower than 1/60sec (probably even not slower than 1/100sec).

    If there was unlikely case, that there was not too dark, then what metering did you use? Try to use other metering modes and see if that changes anything!

    In the video I didn't notice what was the initial ISO? If it was Auto, then in such darkness it could be also set (automatically) to 1600, so this explains why there was no change when the ISO was adjusted manually.
     
  6. MauriceWhite

    MauriceWhite New Member

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    So, summarizing about my question:

    On SJ7 ISO it's always automatic even if you change the values?

    This was a long claimed request on my old SJ5000x elite and finally they admitted that the system did not allow it.
    On SJ5000x elite video settings, you don't have the button to change ISO values (but yes on photo mode)

    On SJ7 I see that on video settings you have the button to change ISO value, but it does not work, isn't it?
     
  7. corallino

    corallino New Member

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    [QUOTE = "MauriceWhite, post: 5519, member: 185"] Quindi, riassumendo sulla mia domanda:

    Su ISO SJ7 è sempre automatico anche se si cambiano i valori?

    SJ5000x e finalmente hanno ammesso che il sistema non lo permetteva.
    Nelle impostazioni video dell'elite SJ5000x, non hai il pulsante per modificare i valori ISO (ma sì in modalità foto)

    Su SJ7 vedo che nelle impostazioni hai il pulsante per cambiare il valore ISO, ma non funziona, non è vero? [/ CITAZIONE]
    It's true, in video the values ISO, EV do not change, while in photos they work. However, I've found that if you take time lapse photos here, the ISO, EV and Long Exposure settings will not work, so making night shots of a starry sky will be a dream.
     
  8. MauriceWhite

    MauriceWhite New Member

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    @corallino I'm sorry but I was about to buy an SJ7 but seeing all this again (I come from SJ5000x and I'm finally very happy after thousands updates and requests to SJTeam) I decided to investigate other brands and finally decided to change. I discarded SJ7 and bought Yi 4K. Fantastic, all works ISO-pal modes-RAW-Shutter Speed-good low light-High bitrate.. etc. I'm sorry for SJ. I think they have a very good hardware but a problem on software developers team.
    Cheers :)
     
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  9. buldozer

    buldozer New Member

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    Yes, it does not work.
     
  10. MauriceWhite

    MauriceWhite New Member

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    It's incredible that SJ don't learn from previous errors!!
    So why they put that setting if it does not work?
    No matter, I finally quit SJ. Now I have a Yi cam and ALL works. ALL.
     
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  11. buldozer

    buldozer New Member

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    It seems there is no other way than to abandon the "sj"
     
  12. RBEmerson

    RBEmerson Humbled by events

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    The ISO setting is only for photos. The video modes adjust the image gain as conditions change. Changing the ISO setting in a video is simply not needed. This is not a nighttime camera. It might be nice to have an infrared capability, but that would come at the price of losing other capabilities.

    @MauriceWhite There really is nothing broken here. You misunderstanding how videos and photos work in the same camera. You can't set video ISO in, for example, a GoPro Hero 5 Black. I have one; it's just not possible. You won't find an action cam that really changes ISO settings (even they claim to do it). If you want to forget the SJ7, that your choice, but don't expect things to get better with any other action cam.
     
  13. Sulev Svilponis

    Sulev Svilponis Elite

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    ISO setting of the SJ5000X works both in the photo and in the video mode. Useful, as this way you can control the noise level and the gain!
     
  14. MauriceWhite

    MauriceWhite New Member

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    This is not true, I've been discussing this for a long time with SJ team and, in the end, after promises and promises they admitted that SJ5000x board does not allow it.
    That's why I planned to buy an SJ7 but all SJ7 users I asked, and all forums told me that the setting was there but is not working, that's why I didn't buy it, and after seeing all the positive opinions I changed to Yi, and I'm very happy with it, all works!
    And I was the fan number 1 of SJcams!, and still think that SJ5000x is a very very very good cam, I've made incredible photos and videos with it.

    I have a GoPro Hero 5 Black and now a Yi 4K and you can adjust maximum ISO on video mode, so if I don't want the camera go upper, for example 800 ISO, I can limit it, and it works (tested). I know that an action cam is not suitable for some kind of recordings, specially at low light etc etc etc but if I plan to record something in a low light situation now I can limit ISO and avoid some kind of noise, and Hero 5 and Yi 4K allow it.
     
  15. Sulev Svilponis

    Sulev Svilponis Elite

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    If that is not true, then how does EV correction actually adjust the video exposure? The aperture is fixed. The shutter speed is also (by fixed fps), the only thing that could be adjustable, is the ISO (amplification of sensor signal).
     
  16. RBEmerson

    RBEmerson Humbled by events

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    Sigh... people, this is an simple action cam. Let go of pretending it's a high-end DSLR or some sort of Arriflex, RED, Sony NXCAM, Canon X-series, etc. It's not and never will be. This camera is great for all sorts of "action cam" things. But trying to compete with cameras that have spendy trick glass in front, huge sensors, tons of processing capability... give it up. Shoot cool video or stills of cool events, have fun with it, and be glad you can.
     
  17. MauriceWhite

    MauriceWhite New Member

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    Sulev: EV and ISO are two different ways to increase or decrease the amount of light captured by the sensor but DIFFERENT.
    SJ5000x let you change the EV value but not the ISO value on video mode. Only photo mode let you change the ISO value.
    I requested thousand times SJ FW team to add this feature but finally they told me that NT96660 the processor was not capable to do it.

    Increasing ISO means increase the sensor sensitivity and consequently image noise.
    Increasing EV will play with shutterspeed and ISO to make your scene brighter (but not you aperture as it's fixed)

    If you can limit ISO, then EV will only raise until the maximum ISO value you choose playing with shutterspeed too.
    That's why it's important for me a camera able to set ISO maximum value, and set it not too high.
    On Yi 4K and Hero5 I set it to 400 on daylight and maximum 800 in night video shots.


    Google EV vs ISO and you'll find many explanations about that.

    :)
     
  18. Sulev Svilponis

    Sulev Svilponis Elite

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    I thought that one can adjust EV (exposure value) by changing either the aperture, the shutter speed or the ISO. If the aperture and the shutter speed are fixed, then changing the ISO is the only way for adjusting EV. Hence one can adjust the ISO by applying negative or positive EV correction.

    There is no different signal amplification methods for ISO and EV correction.
     
    Last edited: Mar 24, 2018
  19. MauriceWhite

    MauriceWhite New Member

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    On SJ5000x elite, on video mode, the ONLY setting that you can change is EV.
    Aperture is fixed (I think is 1.7 or 2.0) --> you cannot change it
    Shutter speed is variable --> you cannot change it
    ISO is variable --> you cannot change it

    When you change the EV value the camera tries to get the best value by combining increasing o decreasing Shutterspeed and increasing o decreasing ISO, I don't know exactly how. If you apply positive values the image will be overexposed or underexposed proportionally to the number you choose (+0,5,+1.0,+1.5 or -0.5,-1.0,-1.5...)

    In Yi4K and Hero5, (aperture is fixed too) I can change:
    - EV
    - Shutterspeed
    - ISO

    SJ5000x doesn't allow to change these values, only EV
    SJ7
    has the ISO setting on video mode BUT everybody I have asked tell me that it doesn't work in the actual Firmware.
    That's why finally I didn't bought it.
    :)

    I am always talking the VIDEO MODE, on photo mode you can set ISO value and works.
     
  20. Sulev Svilponis

    Sulev Svilponis Elite

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    As much as I know about those video sensors, they could be read at several fixed timings. All those possible reading speeds are listed in a table of the sensor specs. The sensor can't read data at random speed. If the frame rate is fixed, then the shutter speed isn't variable at all.

    The EV isn't a single parameter - it's a 3 component parameter, those components are aperture, shutter speed and ISO speed. If 2 of 3 components (aperture and shutter speed) are constant then all the change comes from changes in the third component, hence changing the EV = changing the ISO.

    I'm talking about the Video Mode too.
     

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