MU-43 vs DSLR in low light

Discussion in 'Open Discussion' started by Uwharrie, Jul 16, 2012.

  1. Uwharrie

    Uwharrie Mu-43 Veteran

    May 10, 2012
    North Carolina
    Real Name:
    Lynne Ezzell
    Ok just tried out my G3 with my new to me Pany 20 1.7. While I do think I will enjoy this lens, it seem I have to use. Higher ISO on it for inside shots than with my Canon body paired with a 2.8 lens. Am I just imagining this?
  2. Bhupinder2002

    Bhupinder2002 Mu-43 Hall of Famer

    Hi Mate:smile:
    I am confused now.:confused:
    What exactly you are trying to ask or tell us?This topic has been discussed here many times so please flick through threads. G3 with 20 mm 1.7 is a nice combo and performs well in low light and low light has different definition for different people. I never go beyond ISO1600 and even my EPL2 performs very well as per my needs
  3. lenshoarder

    lenshoarder Mu-43 All-Pro

    Nov 7, 2010
    He's asking why his G3 with a brighter F1.7 lens needs a higher ISO than his Canon with a slower F2.8 lens.

    The answer is that your Canon has a more sensitive sensor. It's an oversimplification to say that a camera with a faster lens will do better in low light than another camera with a slower lens. There are more variables. Sensor sensitivity is one of those.
    • Like Like x 1
  4. Tincam

    Tincam Mu-43 Regular

    Apr 25, 2012
    Real Name:
    I disagree. ISO 1600 is (theoretically) the same on every camera. Of course, some sensors will have different noise results at ISO 1600, but you should get the same light meter reading at ISO 1600 and f2.8 on both the Canon and the G3.
  5. GaryAyala

    GaryAyala Mu-43 Legend

    Jan 2, 2011
    Yes, you are imagining that.

    You may have a different meter mode on one camera than the other ... or you may be metering off different surfaces. Or even a combo of the above.

  6. dhazeghi

    dhazeghi Mu-43 Hall of Famer

    Aug 6, 2010
    San Jose, CA
    Real Name:
    Are you shooting wide open with both? Do the images come out with equal brightness? Is the Canon lens stabilized (the Panasonic 20 on the G3 is not)?

  7. Amin Sabet

    Amin Sabet Administrator

    Apr 10, 2009
    Boston, MA (USA)
    +1 for imagination. If you still have the Canon, try them side by side.
    • Like Like x 1
  8. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    +2 for imagination (I guess we'd be up to 3 now, but who's keeping count?). Using a faster aperture will require a lower ISO to obtain the same exposure. There is no brand involved in that, and the sensor sensitivity is not involved in the calculation. Sensor sensitivity just affects how high you can bump that ISO before losing quality and has nothing to do with what ISO is required at a given aperture.

    But then... you said in comparison to the Canon with an f/2.8 lens. Obviously the Lumix 20mm f/1.7 is a faster lens with the potential for a larger aperture, but you didn't really say which aperture you were using. So just to be sure... you're using Manual or Aperture Priority with the widest aperture, right?
  9. Luckypenguin

    Luckypenguin .

    Oct 9, 2010
    Brisbane, Australia
    Real Name:
    You don't list the focal length of the Canon lens or what sensor format your Canon camera has. There may be some slight differences in the actual versus reported sensitivity of the sensor. Each camera may meter the scene differently. Any difference in angle-of-view between each combination will result in a different scene with differing levels of luminance.
  10. Sammyboy

    Sammyboy m43 Pro

    Oct 26, 2010
    Steeler Country
    ISO 1600 = ISO 1600 = ISO 1600. ISO is the International Standards Organization, therefore, ISO 1600 = ISO 1600 = ISO 1600 regardless of the camera being used.
  11. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    Oh yes, focal length can make a big difference in exposure requirements. Good point, Nic.

    There will certainly be some slight differences in the nuances of the specific cameras and of course the way you meter will make a difference as well. However, we're talking about f/1.7 to f/2.8. That means that if the metering itself is different then you would see a full 1.5 EV stops difference in the final image! Plus you're saying that the camera with the faster lens is using HIGHER ISO, not just the same... So that means there would have to be over a 1.5 EV difference, which I don't think you would be able to miss. ;) So that part goes back to "yes, you're imaging it", but the focal length difference that Nic pointed out can actually account for a full EV or more, if the difference is as much as a standard-wide to a super-telephoto for instance. We're talking about going into a different class of focal length to see that much difference in metering.
  12. lenshoarder

    lenshoarder Mu-43 All-Pro

    Nov 7, 2010
    So here's my quick and dirty experiment. Two cameras side by side. The same type of lens on both, Pentax 50mm F1.4. To make sure the lenses were the same, I checked it again after swapping the lenses. The results were consistent. I set both cameras to ISO 200 and both aperatures to F1.4. Both were set to AWB. I then let each camera meter out the shutter speed. The subject was a white sheet of paper uniformly lit and filling the entire field of view. I took 3 sets of shots. Low, mid and high illumination.

    The setup.


    GF2, low illumination.


    NEX, low illumination.


    GF2, mid illumination.


    NEX, mid illumination.


    GF2, high illumination.


    NEX, high illuminaton.


    Theoretically, the shutter speed should have been the same for each set. For low illumination that was indeed the case. For the others, they weren't.

    In this case, I fixed the variables except for shutter speed. That was allowed to vary and it did. If the shutter speed and aperature were fixed, then the ISO would have varied. As the OP says he has witnessed.

    I may have messed up somewhere since this was done quickly in a few minutes. I can't think of anything but if you spot something, please let me know.
    • Like Like x 2
  13. snapo007

    snapo007 New to Mu-43

    Jul 17, 2012
    should try

    I think you should make this comparison in Manual mode by dialing the same ISO, WB, Shutter Speed and Aperture, take picture with each camera and compare not the image shown on camera's screen but in computer.. I think camera with larger sensor can emmit more light (sensor is familiar to solar panel somehow..) so exposure could be different..
    • Like Like x 1
  14. troll

    troll Mu-43 Veteran

    Jan 25, 2012
    You should've taken the pictures, lenshoarder. Your test shows the differences between the metering systems of those 2 cameras, but not the sensors' sensitivity, to see that you'd need to look at the final pictures. The final exposure from GF2 at 1/500 will likely to look different than the NEX picture at 1/250.
  15. Uwharrie

    Uwharrie Mu-43 Veteran

    May 10, 2012
    North Carolina
    Real Name:
    Lynne Ezzell
    Yep that is what I was asking!
    And I did search the forum first or at least tried to but I seem never to have luck with the search function!

  16. Uwharrie

    Uwharrie Mu-43 Veteran

    May 10, 2012
    North Carolina
    Real Name:
    Lynne Ezzell
    Shooting wide open ( why else would I have fast lens for low light)
    The shorter focal length lens (tamron) on the canon is not stabilized. I will do a side by side today
    Aperture priority, manual ISO. I noticed I had to keep bumping up the ISO to get a usable shutter speed. Focal length similar canon may have been a little longer since it is a zoom.
    I think I may be expecting too much from the Pany 20 1.7. I really thought I would be able to shoot in low light (inside home with normal lighting) at around ISO 800
    Thanks again for all the responses. This group has a wealth of knowledge and it is so nice that folks share that knowledge

  17. fredlong

    fredlong Just this guy...

    Apr 18, 2011
    Massachusetts USA
    Real Name:
    ISO has little to do with sensor sensitivity. Every sensor has some base sensitivity to light. This is electrically measurable. Next, in a combination of hardware and software, the signal is amplified to be equivalent to various ISO sensitivities.

    The ISO a camera is set to is often inaccurate. I've seen tests at DXO showing as much as a full stop under or over the stated ISO. Most seem to overstate the ISO slightly. The measured ISO on the G3 is slightly under the stated ISO. You can compare this to your Canon here DxOMark - DxOMark by DxO Labs

  18. fredlong

    fredlong Just this guy...

    Apr 18, 2011
    Massachusetts USA
    Real Name:
    I'll also add that the same f-stop on two different lenses won't always give you the same amount of light. There is also a transmission loss of light going through the all the glass. It's usually small enough to be insignificant and not too important if you're metering through the lens. In cinematography lenses are often rated in t-stops which factor in the transmission loss. This allows identical exposure when changing lenses or on multiple cameras.
  19. NJH

    NJH Mu-43 Regular

    Mar 8, 2012
    South West England
    Different cameras meter differently for a different tone curve target for their jpeg processing. I compared my X100 and E-P2 back to back in a similar fashion, pointing at a dimly lit wall the X100 wants to use 2/3 stop more exposure than the E-P2. IMHO the X100 does tend to overexpose in aperture priority anyway, especially in a low contrast situation.

    Also IMVHO with identical exposure values on each camera, chimping the captured image of my bedroom wall looked pretty much the same to me, enough to convince me that the 2/3 of a stop difference that the camera wants to use is just down to its metering and nothing to do with actual amount of exposure.
  20. Hikari

    Hikari Mu-43 All-Pro

    Nov 26, 2010
    First, there are different standards for ISO. So ISO may not match.

    Second, , vignetting can influence metering.

    Third, metering can be different among cameras.

    Forth, metering can be different when using an adapted lens.

    Fifth, the curve applied to the image can effect exposure.

    You are going to have to work harder to come to any firm conclusions. So far you have not identified the variables.