RAW capture and processing: exposing to the right

Discussion in 'Photography Techniques' started by stillshunter, Dec 28, 2011.

  1. stillshunter

    stillshunter Super Moderator Emeritus

    Nov 5, 2010
    Down Under
    Real Name:
    Mark
    I've heard the term and sort of grasped the ideas behind it, but this article really helped me understand the technique in practical terms.

    Hope you enjoy or get some value from it.
     
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  2. norman shearer

    norman shearer SC Veteran

    Nice link. I used to ETTR with my GH2 and it did help me to better control the noise. I set the camera up so that it showed a short preview picture with "blinkies" turned on and from previous experiments with Photoshop RAW I got to know what level of "blinkies" I could recover in processing. I've yet to try out similar experiments with my 5N or GRDIV - must get around to testing them out.

    Something else I'm curious to explore is adjusting contrast, sharpness and saturation in camera and seeing just how much they affect the raw file..
     
  3. pdh

    pdh SC Legend

    Jan 2, 2011
    hmm
    I've been struggling to "get" this technique since I first got my E-P2 and have read a few articles ... I think I'm finally getting there.
    I liked this chap's style, although I found his English a little confusing occasionally (although I'll criticise properly when my Finnish is as good ) ... plus his E-P2 seems to have settings mine doesn't?
     
  4. stillshunter

    stillshunter Super Moderator Emeritus

    Nov 5, 2010
    Down Under
    Real Name:
    Mark
    Paul I think he started out with the EP-2 but writes this article from the perspective of his EP-3. Could be wrong but that's the impression I get from his opening preamble.

    Thanks for the blinkies tip Norman. Let us know how you get on with the adjusting your contrast, sharpness and saturation in camera. I would have thought this shouldn't have any affect on the RAW file, but be very curious to know if your results yield anything different....as this would open the doors to another world of in-camera micro-adjustment, and possibly more latitude with the ultimate RAW files.
     
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  5. pdh

    pdh SC Legend

    Jan 2, 2011
    He gives E-p2 settings first then goes onto discuss how he works it on the E-P3 ... maybe I'll drop him a line for clarification
     
  6. stillshunter

    stillshunter Super Moderator Emeritus

    Nov 5, 2010
    Down Under
    Real Name:
    Mark
    Thanks Paul, be sure to keep us updated mate. Hey maybe a good time to test out and brush-up on your Finnish mate :wink:
     
  7. kyteflyer

    kyteflyer ~@¿@~

    Jan 31, 2011
    Newcastle, Australia
    Real Name:
    Sue
    Looks like something which can be applied across the board, not just in the PENs? VERY interesting article.
     
  8. Luckypenguin

    Luckypenguin SC Hall of Famer

    Dec 24, 2010
    Brisbane, Australia
    Real Name:
    Nic
    The noise reduction example doesn't really add up for me. If he can afford to hand-hold the ETTR image at 1/15 sec using ISO 1600, why does the non-ETTR image need a shutter speed of 1/50? Surely it could be shot at 1/15 and ISO 400 which would dramatically change the noise levels (certainly on a 12MP m4/3 camera!). The theory appears correct: less noise for equal ISO values, but in practical terms you can use lower ISOs when you aren't over-exposing anyway.

    I can only really see the technique working for images which don't have a large variance in exposure across the frame i.e. where you CAN overexpose without seriously clipping highlights.
     
  9. pdh

    pdh SC Legend

    Jan 2, 2011
    The most interesting thing for me was the emphasis he put on the camera histogram not being a true reflection of the raw data ... never seen that stated before in ETTR articles, and I wondered if it was definitively true for all cameras ...
     
  10. bartjeej

    bartjeej SC Hall of Famer

    Nov 12, 2010
    Real Name:
    bart
    ^ I've read it before (it's been mentioned in several articles on luminous landscape), and I believe it is true for my EX1 although I haven't tested it specifically.

    I must say I've started using the image on the screen more than the histogram to judge my exposure, since the histogram disappears as soon as I start dialing in exposure compensation, so I'd be going into EV comp, dial in a bit, go out of EV comp to see the histogram, possibly go back to adjust more, see if it was enough again... well you get the picture, it's a PITA. Only in manual mode is the histogram displayed at all times.

    The way I understand ETTR, it's not so much about noise control but more about giving you (even) more options to get a contrasty scene than a normally exposed raw file does.
    If the image data is bunched up relatively tightly in the tone-rich higher stops, you can apply a steep contrast curve without any banding or sudden tonal transitions: in a 12-bit sensor, like the article says the lightest stop has 2048 possible values and the darkest stop has 2 possible values. Already the 9th lightest stop has only 16 possible values.

    Therefore, if you have a 6-stop scene exposed right around the middle of the tone curve, the darkest stop in this scene falls into this band with only 16 possible tonal values. Even if you adjust the exposure in post-processing to stretch the 6-stop scene to go from pure black to pure white (drastically increasing contrast), all the data in the darkest stop will still be divided over only 16 tonal values, giving very abrupt transitions or banding (and lots of noise). If you had exposed to the right, the darkest stop in your scene would have 64 possible tonal values, giving a much smoother look if you apply the same strong contrast.
     
  11. olli

    olli Super Moderator Emeritus

    Sep 28, 2010
    Metro Manila
    Real Name:
    olli
    Here is the most recent LL article on this subject.
     
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  12. stillshunter

    stillshunter Super Moderator Emeritus

    Nov 5, 2010
    Down Under
    Real Name:
    Mark
    Great addition to this subject Olli. Thanks mate :thumbup: Now I wonder who will be the first SC manufacturer to cash-in on LL's thinking here. I'd like to put even money on Fuji and Sony :wink:....and a dollar on the long odds that Pentax is the first to innovate...
     
  13. pdh

    pdh SC Legend

    Jan 2, 2011
    he's amended the article slightly to clarify E-P2/E-P3 settings
     
  14. stillshunter

    stillshunter Super Moderator Emeritus

    Nov 5, 2010
    Down Under
    Real Name:
    Mark
    Great that he responded. So was he confusing the EP2 and EP3?
     
  15. pdh

    pdh SC Legend

    Jan 2, 2011
    yep - I couldn't find "keep warm" in my E-P2 menus, and of course it's an E-P2 setting
     
  16. stillshunter

    stillshunter Super Moderator Emeritus

    Nov 5, 2010
    Down Under
    Real Name:
    Mark
    Of course that's "EP3"....or have you caught the reviewer's disease? :laugh1:
     
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  17. Naveed Akhtar

    Naveed Akhtar SC Regular

    186
    Dec 8, 2011
    London, UK
    Funny I also wrote the same concern on that blog link. The technique to me is really not holding much benefit to acheive the lower noise at higher ISO, specially when ISO is increased for quick exposures (freeze motion, hand-shake reduction etc) however it can be used even on very low ISO or base ISOs to reduce noise in latest M4/3 where base ISO is already high (starting 200 in some case) AND specially where you are not already worried for blown-up highlights, again mostly in Oly Pen sensors.

    So in nutshell I would only use ETTR when light is mostly uniform accross the frame and I have enough available light to get more exposure for intended subject and I want to get still better contrast and safeguard for my post-processing recovery.

    Otherwise there were many times I even went for ETTL =]] and leave the noise to be picked later in PP :p
     
  18. norman shearer

    norman shearer SC Veteran

    Your right, I tried numerous combinations and shot the same scene - all pictures looked the same! So I guess these adjustments are purely for your previewing pleasure only.
     
  19. grebeman

    grebeman Old Codgers Group S.C. Charter Member

    Jul 13, 2010
    South Brent, south Devon (UK)
    Real Name:
    Barrie
    Using a spotmeter

    I first became aware of the article quoted by olli some time ago. With some nice cloud formations today I decided to use my Sekonic L-508 spotmeter and then manually set the exposure on my GF1 with the data obtained from the spotmeter which was set to the same iso as the camera.

    I metered the whitest area of the cloud that I could locate and then dark shadows, getting the meter to then average the readings. I also tested the incident lightmeter feature with the Sekonic. However I found that the best method was to take the highlight reading and then reduce that exposure value by 2.5 stops. Any more and I started to get burnt out areas, although usually slight, in the image. Often the average reading and the incident reading above also resulted in the brightest areas beginning to burn out, in other words the average reading resulted in the highlights being placed just beyond the peak of the tone curve for the Panasonic sensor.

    I then used curves to try and slightly lift the shadow values, detail had been recorded in the shadows but too much lifting of the shadows would result in some posterisation of the shadows.

    [​IMG]

    [​IMG]

    [​IMG]
    All taken using a Panasonic GF1 with Voigtlander 15mm f/4.5 Super Wide-Heliar lens, exposure settings derived from data obtained using Sekonic L-508 Zoom Master

    Barrie
     
  20. pictor

    pictor SC All-Pro S.C. Charter Member

    Jul 14, 2010
    In theory ETTR is fine, but in reality I am struggling with burnt out highlights most of the time.