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What is the trade off when switching to "High ISO NR ?

Discussion in 'Open Discussion' started by roundball, Feb 23, 2015.

  1. roundball

    roundball TalkEmount Hall of Famer

    Oct 8, 2013
    USA
    EXAMPLE: NEX-7 High ISO NR (Noise Reduction) Menu Settings
    HIGH
    NORMAL (default)
    LOW

    Don't know about different models, but the NEX-7 has a High ISO NR feature.
    Usually, whenever some deviation is taken from a “normal”, “default”, “middle of the road” type of setting with most anything, the benefit gained is usually at the expense of something else being traded off.

    On an impulse just before dark today, I took a couple of shots at ISO400 with HIGH ISO NR set to HIGH and the results had surprisingly less noise than ISO400 usually has for me.
    But with only a couple shots I didn't think to watch for anything else changing as a result of using the HIGH NR setting.

    Trying to figure out if there is a negative trade-off of something else by doing this...like some other element of IQ, or loss of shutter speed, etc.
    Or if its simply some on-board camera NR processing that takes place after each shot?

    Anybody actually know for certain what the situation is with the NEX-7 ?
     
  2. xXx1

    xXx1 TalkEmount All-Pro

    Jan 15, 2013
    I think that the noise reduction works by taking a second picture shutter closed and uses this as basis what to remove. Pure speculation, I shoot RAW and I think that these have not got the NR applied. No really negatives, it is maybe slightly slower.
     
  3. roundball

    roundball TalkEmount Hall of Famer

    Oct 8, 2013
    USA
    Do you mean shot to shot through-put speed is slowed down due to on-board processing of each shot?
     
  4. soeren

    soeren TalkEmount Top Veteran

    651
    Dec 12, 2014
    Næstved, Denmark
    Soeren
    Im not sure if this is exactly the same but using in camera NR and longer shutterspeeds e.g 10 sec the camera will be unoperational for another 10 sec due to the mentioned second exposure.
     
    • Informative Informative x 1
  5. xXx1

    xXx1 TalkEmount All-Pro

    Jan 15, 2013
    Yes. Not sure of this however.

    Long exposure NR definitely works by taking a blank exposure after the real one. That way they can take into account different lightning situations in different parts on sensor.
     
    • Informative Informative x 1
  6. roundball

    roundball TalkEmount Hall of Famer

    Oct 8, 2013
    USA
    Well, I've been shooting birds in a snowfall this morning with otherwise normal settings and shutter speeds in the 1/80 and 1/100 range, haven't noticed anything different so that's good.

    Also just posted a 60 second video in the Nature section using ISO400 and a Canon 400mm lens on the NEX-7 and it turned out fine as far as I'm concerned.

    So unless / until I experience a down-side, I'll continue to use this "HIGH ISO NR" setting as a normal part of my set-up.
     
  7. WestOkid

    WestOkid TalkEmount All-Pro

    Jan 25, 2014
    New Jersey, USA
    Gary
    You are confusing "long exposure NR" with high ISO NR. Long exposure NR takes a second picture with the shutter closed to identify hot pixels on the sensor. Hot pixels are not typical noise and cannot be removed by NR in post. You have to find the hot pixels and handle them individually if the exist. Long Exposure NR also affects raw while High ISO NR only affects JPG.

    High ISO NR kicks in at a certain ISO. I am not sure what level but let's say its 1600. A stronger NR algorithm is used. The down side is that you can lose some detail. Also, you lose grain and for some people shooting scenes like bars, concerts and street photography, that noisy grain from high ISO can be a compelling part of the image.
     
    • Informative Informative x 2
    • Agree Agree x 1
  8. roundball

    roundball TalkEmount Hall of Famer

    Oct 8, 2013
    USA
    Any idea if and where sony might have this documented / explained in more detail?
    Not challenging you personally, just that I noticed a difference using ISO400...unless it was just a coincidence.
     
  9. roundball

    roundball TalkEmount Hall of Famer

    Oct 8, 2013
    USA
    Found this NEX-7 High ISO NR Test...seems like the benefits might be progressive through the ISO range.

    http://www.imaging-resource.com/PRODS/NEX7/NEX7HI_ISO_NR.HTM

    IR.com's Testing Summary Comment:
    "...it appears that the NEX-7 already applies "High ISO Noise Reduction" at the base ISO, as there are subtle differences in fine detail between the settings already at ISO 100. It starts to become more obvious at ISO 800 and above..."
     
  10. WestOkid

    WestOkid TalkEmount All-Pro

    Jan 25, 2014
    New Jersey, USA
    Gary
    I don't know that it is 1600. That's why I said, "let's say ISO 1600". I remember looking into it some time ago and couldn't find any specifics on what constituted high ISO. I am not sure why Sony wouldn't make this clear. The only thing I can think of is that it gives them some latitude to adjust the setting camera to camera and firmware to firmware without changing the general documentation. So for the NEX 7, maybe ISO 400 is considered high ISO whereas the A7 it would be much greater.
     
  11. WestOkid

    WestOkid TalkEmount All-Pro

    Jan 25, 2014
    New Jersey, USA
    Gary
    OK. Good to know. Apparently it starts early, but they say it isn't as obvious until ISO 800. Roundball found otherwise.
     
  12. roundball

    roundball TalkEmount Hall of Famer

    Oct 8, 2013
    USA
    Yes, in general, sony's documentation is very weak to say the least.

    I shoot so much with 300-400 teles in low light that I'm constantly fighting low shutter speeds.
    But haven't liked the noise in ISO200, and ISO400 is even worse of course.
    If this setting will now let me get by using ISO400 without any major downside, it'll be a big plus.
    Should know in a few days of my normal shooting if it's worth leaving it set at HIGH NR.
     
  13. xXx1

    xXx1 TalkEmount All-Pro

    Jan 15, 2013
    It may be worthwhile to compare external noise reduction software too. I use NeatImage occasionally being Linux person.
     
    • Informative Informative x 1
  14. roundball

    roundball TalkEmount Hall of Famer

    Oct 8, 2013
    USA
    Yes, and that's in Lightroom too
     
  15. roundball

    roundball TalkEmount Hall of Famer

    Oct 8, 2013
    USA
    Just as an update, in comparing photos for in-camera noise reduction, I concentrated so much examining the open background areas for noise that I didn't pay much attention to overall elements of IQ, will do more of that starting today.
    Reason I say that is in experimenting with other photo tests in Lightroom, I noticed that as the amount of LR's Noise Reduction is increased, there is a corresponding loss of sharpness in the overall image itself.

    My conclusion is that same thing would occur when the in-camera NR settings are increased higher..so I expect that's going to be the trade off I was wondering about.
    Today, I'll experiment shooting a scene(s) with High ISO NR set to NORMAL, then immediately re-shoot with High ISO NR set to HIGH and compare.
     
  16. xXx1

    xXx1 TalkEmount All-Pro

    Jan 15, 2013
    Noise reduction works by removing details. Most of these details are unwanted noise but it is unavoidable that some needed details are lost too. I have a hunch that separate noise reduction software may be much better than camera ones. I am waiting 16 bit GIMP so that I would be able to use NeatImage more.