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01-17-2016, 10:24 PM   #1
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K3 Light Sensitivity

Hi all,

Is it possible for a individual copy to be very insensitive to light while talking pictures that are otherwise sharp and well exposed? I find myself constantly forced to use very high ISO settings (3200 and 6400) with my k3, and I'm beginning to wonder if this isn't normal. It remains true with the 100 D-FA f2.8 WR Macro, the 60-250 F4.

Thanks,

Bret

01-17-2016, 10:31 PM   #2
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Can you elaborate on your most common shooting conditions, indoor/outdoor, cloudy and type of subject?
01-17-2016, 10:33 PM - 1 Like   #3
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Try a test in all manual and take a number of exposures from wide open to say f/11. Change only the aperture setting, leave everything else alone. Using the 100mm macro. Tripod and fixed target. Take a look and see if each exposure is different. They should be, but if not it would indicate a problem with the aperture mechanism.

It seems unlikely to me that there would be a problem with the sensor. You might also check to make sure you do not have some exposure compensation dialed in.
01-17-2016, 11:14 PM   #4
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QuoteOriginally posted by Stavri Quote
Can you elaborate on your most common shooting conditions, indoor/outdoor, cloudy and type of subject?
I shoot in many kinds of conditions, and I am always surprised at the high ISO required to get sharp focus, decent shutter speeds, and lenses stopped down from wide open.

My history as a photographer involves a lot of film shooting in rainforest situations, which are very dark. Even in those conditions I was able to freeze animal motion, hand held with a 200mm 2.8 lens with film that never exceeded 800 ASA. With my K3 and the 60-250 f4 I feel I would be struggling with a slow shutter speed and lens near wide open at 3200 ISO. I know they are not entirely comparable as my 200 f2.8 was a stop faster, with a lot less reach. But still the ASA and ISO experiences are as if from different planets.

---------- Post added 01-17-16 at 10:20 PM ----------

QuoteOriginally posted by jatrax Quote
Try a test in all manual and take a number of exposures from wide open to say f/11. Change only the aperture setting, leave everything else alone. Using the 100mm macro. Tripod and fixed target. Take a look and see if each exposure is different. They should be, but if not it would indicate a problem with the aperture mechanism.

It seems unlikely to me that there would be a problem with the sensor. You might also check to make sure you do not have some exposure compensation dialed in.
Yes, a rigorous test is a very good idea. Even better if I knew someone else with a k3 that I could test side. But I'm certain that the aperture stops down properly. And no, I don't have exposure compensation on unintentionally. I use it when a scene requires it, and then I restore it.

Everything works right--the pictures are sharp and the metering is good. The sensitivity just seems low, which I agree, seems very unlikely.

01-17-2016, 11:26 PM - 2 Likes   #5
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QuoteOriginally posted by BretW Quote
Even in those conditions I was able to freeze animal motion, hand held with a 200mm 2.8 lens with film that never exceeded 800 ASA. With my K3 and the 60-250 f4 I feel I would be struggling with a slow shutter speed and lens near wide open at 3200 ISO.
Yes, in my opinion what you are experiencing is normal, considering the crop factor, pixel pitch and aperture of your lens. Firstly, the shutter speed rule of film days (shutter speed = 1/focal length) was valid for 24x36mm format, now with APSC, you need to multiply this shutter speed by x 1.5 . Secondly, the 24Mpixels sensor is more demanding in terms of the amount of blur you can afford relative to pixel size when you look at your images 100%. But, last but not least, compared to film days, now you have SR (shake reduction) that allow you to lower your ISO by up to 4 stops. What you can do to get the best out of your K-3: use TAv mode, set ISO to ISO Auto, and set your shutter speed manually to what you want based on the focal length you're using, e.g between 1/90th and 1/180th sec. for 200mm focal length, set you K-3 to burst mode so that you may have some blurry shots but a number of sharp shots as well.
01-18-2016, 06:03 AM   #6
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QuoteOriginally posted by biz-engineer Quote
TAv mode, set ISO to ISO Auto,
TAv mode ISO is automatically set to auto. One can't manually adjust it.

Which metering are you using? That will affect light sensitivity along with the other items mentioned. You can customize the ISO range limit for the shooting situation, use spot metering or if it is dark enough cover slap a Flash on with a Flash multiplier. There are a number of way to set your camera for different lighting. Todays cameras will handle High ISO much better than film did, the 800 asa film while able to stop action in darker cover would also have a good bit of grain as I remember.

Last edited by Oldbayrunner; 01-18-2016 at 06:57 AM.
01-18-2016, 06:29 AM   #7
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Which mode are you shooting in TV, AV, P etc. ?
01-18-2016, 07:33 AM - 1 Like   #8
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I'd like to point out that ISO 800 at f2.8 is only one stop from ISO 3200 at f4. However I'm unclear if the shutter speed was similar.

Additionally, the T-stops of lenses vary and when you cross compare exposures between lenses of different complexity (prime vs zoom) you can sometimes see a 1/3 to 1/2 stop difference at the Same f stop.

Finally, if you shot prints with film you could underexpose by 2-3 stops and get good prints - and not have to do anything other than ask for prints, the machines or the human printing would adjust for good results.

In digital you can underexpose but you have to do the adjustment.

01-18-2016, 07:43 AM   #9
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QuoteOriginally posted by BretW Quote
It remains true with the 100 D-FA f2.8 WR Macro...
With the macro, the effective f/stop changes significantly at close focus distances, see Macro Camera Lenses. The camera's auto-exposure meter will compensate for this with a higher ISO or longer shutter, but this may account for the exposure settings not lining up with an external meter or images taken at a lower magnification.
01-18-2016, 09:03 AM   #10
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I would say, since I shoot both film and digital, that the K-3 meters really good. If I do a shoot with both cameras I use the same settings on both cameras and get equal results, i.e there is not a large differens between old 100 ASA and the new 100 ISO.
03-21-2016, 09:46 AM   #11
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I have the same issue. I have a K5 IIs and K3 and carry both with me to avoid constantly having to change lenses, which when on a boat with salt water spraying all over the equipment, is dangerous.

For a number of weeks I have felt that the K3 is having to use slower shutter speeds or higher ISO settings than the K5 would in the same circumstances, just to be correctly exposed.
So yesterday I went to the coast and took some shots with my 60-250 DA*, 70mm DA Ltd and 16-45 DA with both bodies, within 60 seconds of one another, ensuring they both had zero exposure compensation set and used single point spot metering.
Most of the K5 shots in Av mode (aperture set to f8 in all cases) were around 1/500th to 1/1000th whereas the K3 used 1/30th or 1/20th.
In TAv mode the K5 used ISO160 or 200 whereas the K3 used 800 or 1600.
I will try to upload some photos tonight but, in the meantime, any advice please?
03-21-2016, 02:11 PM   #12
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Was the ISO set to automatic in both cameras?

Thanks

Randy
03-21-2016, 03:41 PM   #13
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QuoteOriginally posted by Rob Shepter Quote
in the meantime, any advice please?
There are lots of potential variables here: lots of camera settings, differences in lenses etc. Some suggestions/speculations:

- Look into shooting with identical metering modes (eg centre-weighted), to see how that performs.
- Check your K-3 setting for Auto-ISO parameter adjustment - set it to 'Slow'. Set it the same on the K-5.
- Check your P mode program line setting and set it to the same thing in both cameras - eg 'MTF priority' or 'DOF Priority - Shallow'. (Behind the scenes I think it may have an influence, even if you aren't in P mode).
03-21-2016, 04:13 PM   #14
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Yes, in TAv mode ISO was set to auto. In Av mode it was set to ISO100.
03-22-2016, 01:02 PM   #15
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QuoteOriginally posted by rawr Quote

- Look into shooting with identical metering modes (eg centre-weighted), to see how that performs.

- Check your K-3 setting for Auto-ISO parameter adjustment - set it to 'Slow'. Set it the same on the K-5.

- Check your P mode program line setting and set it to the same thing in both cameras - eg 'MTF priority' or 'DOF Priority - Shallow'. (Behind the scenes I think it may have an influence, even if you aren't in P mode).
Both cameras were set to centre spot metering. I'm supposing the metering is the same, or similar, between the two as I can't find any mention on Ricoh.com of any "fantastic new metering system" for the K3 over the K5II/IIs.

I will look at the Auto ISO settings on both but had assumed that if one camera thinks it should be 1/1000th at ISO100 the other should not want both a much slower shutter speed AND a much higher ISO, only either one or the other, dependent on the Auto ISO setting.

If, and it is a big IF, the P mode settings affects the behaviour in Av or TAv mode, then I give up and will sell both of them and stick to just my *ist and *ist D.
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