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1 EV darker photographs


loverofthelight

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I think you didn't understand me. It's not about how to deal whit different exposure, I know all that stuff. It's just about the difference, at same settings, same object distance. Now I know that the thing is probably in lenses but it's still strange to me, why at same apertures, object distance there is more DOF with summicron than with canon/nikon/sigma lenses. Consequently there is also darker image. It's just that the summmicrons at f2 are the same as other lenses at f2.5-2.8. Does anybody else have that experience?

 

Yes, I think you are right. To my understanding an exposure should be done in a way so that the brighness of a picture is „correct“. Now you might expect that this is the same with Canon, Nikon or Leica. There is one thing to consider: Not each lens lets exactly the same amount of light through but these differences are minor.

 

Do we not see an explanation in the DxO data that shows that the ISO is about 1 EV „wrong“ in the M10? As a consequence the brightness of the final picture must different. Of course.

 

All the other explanations above seem not to be right to me. This effect has nothing to do with Rangefinder, the way it measures etc. The amount of light you let through the lens can be measured in terms of aperture, ISO and exposure time. If the markings of these settings on the buttons or wheels of your camera are incorrect, then the result is incorrect. Of course.

Edited by Alex U.
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You are mostly incorrect but I’ll let someone else explain why as I thought my post above was pretty clear but apparently not so I’ll let someone else have a go.

 

Yes, I think you are right. To my understanding an exposure should be done in a way so that the brighness of a picture is „correct“. Now you might expect that this is the same with Canon, Nikon or Leica. There is one thing to consider: Not each lens lets exactly the same amount of light through but these differences are minor.

 

Do we not see an explanation in the DxO data that shows that the ISO is about 1 EV „wrong“ in the M10? As a consequence the brightness of the final picture must different. Of course.

 

All the other explanations above seem not to be right to me. This effect has nothing to do with Rangefinder, the way it measures etc. The amount of light you let through the lens can be measured in terms of aperture, ISO and exposure time. If the markings of these settings on the buttons or wheels of your camera are incorrect, then the result is incorrect. Of course.

 

Sent from my iPhone using Tapatalk

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I think you didn't understand me. It's not about how to deal whit different exposure, I know all that stuff. It's just about the difference, at same settings, same object distance. Now I know that the thing is probably in lenses but it's still strange to me, why at same apertures, object distance there is more DOF with summicron than with canon/nikon/sigma lenses. Consequently there is also darker image. It's just that the summmicrons at f2 are the same as other lenses at f2.5-2.8. Does anybody else have that experience? 

It is quite normal that there is an apparent difference in DOF. It is not an absolute. The design of the lens determines the rendering of OOF areas. As DOF is a subjective phenomenon, we will certainly experience a difference in DOF perception between different lenses of the same focal length. As Leica  - and especially Peter Karbe - gives an unusual amount of attention to the rendering of the lens outside the plane of focus, it is logical that you will see this effect most when looking at Leica images.

 

I am completely lost when you see a link between DOF and exposure, however.

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Do we not see an explanation in the DxO data that shows that the ISO is about 1 EV „wrong“ in the M10? 

 

This seems the most reasonable explanation.  From my understand of the OPs post his observation has nothing to do with metering. To explain a noticeable difference when one the same sets aperture, shutter speed and ISO for a lens of the same focal length, while there could be disparities in the precision of the the first two variables, the largest one is the accuracy of the sensors ISO rating.  One question out of curiosity would be, what iso was being utilized for the comparison?

 

Regardless, there is a lot of truth to personal preferences around the brightness of the exposure.  Like others here, I typically expose at -1/3 EV. 

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The ISO fact sheets give the ISO rating of film by densitometric measurements under controlled light and standardized development.

 

Sensor ISO values are defined as an equivalence to film. This gives camera manufacturers a considerable leeway in defining the ISO settings of their cameras. Leica is notoriously conservative.

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I am completely lost when you see a link between DOF and exposure, however.

 

Poster is stating that the Leica at f/2 is, in practice, actually like a nikon lens at f2.5 (I.e. the apertures are not exactly equivalent as indicated between the two makers of the lenses). This would account simultaneously for the Leica having slightly deeper DOF, and darker exposure.

 

Whether or not this is true or useful, that I'm not sure. 

 

Poster has not addressed the metering issue - if one is using an auto exposure mode then the metering system could account for the difference - since the Leica metering system is quite limited and best used as a guideline in any situation with dynamic light. If you are using manual exposure at the same setting, then yes, there is a difference in either the equivalency of the ISO, f stop, or shutter speed...my guess is that the difference is in the sensor as we've already had a lot of discussion about the someone what strange characteristics of the Leica ISO measurements. But who knows. 

 

Personally, I think it's best to think of each camera manufacturer's system as a new system that operates on it's own rules. They will use universal indicators, but there is no guarantee they will be equivalent - those are best thought of as guidelines - learn your own rules for camera use with those guidelines as a starting point. 

Edited by pgh
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I don't think that is the case - the f value is a mathematical relationship between focal length and optical diameter.

To judge the actual transmission we would need to know the T-stop. Even then, it would not affect DOF - those are other design considerations.

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So as these discussions often up my curiosity about things, I took a quick peak at the specs over on BH which describe the current  Summicron as 52.3mm with an angle of view of 47 degrees.  Both the Nikkor 50mm 1.8 and 1.4  are listed as 50mm with an angle of view of 46 degrees.  I suspect the Leica numbers are accurate. The question is are the Nikon's? I was under the impression that focal length dictated AoV, but now I'm wondering if the optical formula can alter such things. Struck me as odd that, if accurate, the Nikon numbers describe a shorter lens design with a narrower AoV when one would have expected the opposite.  

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Do we not see an explanation in the DxO data that shows that the ISO is about 1 EV „wrong“ in the M10? As a consequence the brightness of the final picture must different. Of course.

 

Depends: https://en.wikipedia.org/wiki/Film_speed#Digital_camera_ISO_speed_and_exposure_index

 

Any differences in DoF of '50' mm lenses at the same aperture is at most marginal. Any differences in exposure are small and depend on the methodology utilised to determine dISO and metering precision, accuracy of shutter durations and aperture. If all these are at one extreme of tolerance' on one camera and the other extreme on the other then there may be a visible difference, otherwise we are talking nuances. I suspect that the comparison stated is quite simply not accurate enough to be at all definitive.

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Going back to the TO he does not mention DoF at all. He says that brightness of his M10 is less than with Canon, Nikon. As a matter of fact DxO shows that the ISO value shown on the ISO wheel on the M10 differs by about 1EV compared to the „real“ ISO. When Jaapv now claims that Leica is very conservative („Leica is notoriously conservative“) we can say that the contrary is true: An ISO value of 1600 on the ISO wheel of the camera is around (roughly) ISO 800 as the true value. This would explain why the M10 renders darker pictures than Canon or Nikon. Both of these brands (lets take the D850 or the 5D Mk IV) have ISO values that sit very near the line of the DxO graph.

 

I agree that all of this has nothing to do with DoF or Bokeh. I talk just of the brightness of the picture with some defined settings. And this has nothing to with the way how the light is measured by the camera either: When I take a 50mm lens and adapt this same lens on 3 different cameras and set those cameras all to 1/60s and f/5.6 and ISO 200 then the brightness of the resultung picture should be the same.

 

The M10 picture being too dark can be explained by the deviation of the ISO value by about 1 EV. Indeed it could be a deviation of exposure time or aperture as well. But we have no indication that this could be the case. We know only about deviation of the ISO value.

 

I wonder where the misunderstanding is. Do we all talk of different things?

Edited by Alex U.
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When I take a 50mm lens and adapt this same lens on 3 different cameras and set those cameras all to 1/60s and f/5.6 and ISO 200 then the brightness of the resultung picture should be the same.

 

It needn't be. What is a 'correct' exposure? Should all images produce the same the rgb values for an 18% reflectance card? Take a look at the different ways in which digital ISO is measured. Consistency depends on utilising the same criteria for each camera. This needs checking before any conclusion is drawn.

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Going back to the TO he does not mention DoF at all. He says that brightness of his M10 is less than with Canon, Nikon. As a matter of fact DxO shows that the ISO value shown on the ISO wheel on the M10 differs by about 1EV compared to the „real“ ISO. When Jaapv now claims that Leica is very conservative („Leica is notoriously conservative“) we can say that the contrary is true: An ISO value of 1600 on the ISO wheel of the camera is around (roughly) ISO 800 as the true value. This would explain why the M10 renders darker pictures than Canon or Nikon. Both of these brands (lets take the D850 or the 5D Mk IV) have ISO values that sit very near the line of the DxO graph.

 

I agree that all of this has nothing to do with DoF or Bokeh. I talk just of the brightness of the picture with some defined settings. And this has nothing to with the way how the light is measured by the camera either: When I take a 50mm lens and adapt this same lens on 3 different cameras and set those cameras all to 1/60s and f/5.6 and ISO 200 then the brightness of the resultung picture should be the same.

 

The M10 picture being too dark can be explained by the deviation of the ISO value by about 1 EV. Indeed it could be a deviation of exposure time or aperture as well. But we have no indication that this could be the case. We know only about deviation of the ISO value.

 

I wonder where the misunderstanding is. Do we all talk of different things?

Well, that depends which way you define "conservative" ETTR or ETTL.

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And this has nothing to with the way how the light is measured by the camera either: When I take a 50mm lens and adapt this same lens on 3 different cameras and set those cameras all to 1/60s and f/5.6 and ISO 200 then the brightness of the resultung picture should be the same.

Unfortunately, that does not hold true in the digital world, where the values are undefined and ISO just a quantification of amplification.

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For those who really (emphasis intended) want to delve into the intricacies of metering and meter calibration, there is an excellent (imho) article on the web by Jeff Conrad http://www.largeformatphotography.info/articles/conrad-meter-cal.pdf which covers luminance, exposure, light measurement, grayscale reference and calibration and their not-so-obvious limitations. The article is rooted in an analog film approach, but the general principles apply to any metering in any camera, although the characteristic curves of film differ fundamentally from digital sensors, which may have very different response parameters among themselves.

 

Of course, the matter will be even more complicated on entering spot vs. centre-weighted vs. average vs. multimatrix vs. context-sensitive metering... And even more so with regard to the different links in the imaging/ processing chain and their respective characteristics.

 

I would second William with his caveat that overthinking the technical aspects may limit one's photography. On the other hand some great photographers like Ansel Adams gave these matters a lot of thought, whereas others like HCB did not seem to care very much about them. So it seems difficult to formulate a general rule.

 

Kind regards

Mathias

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..... overthinking the technical aspects may limit one's photography.

 

Again, it depends. Knowing your equipment and how it works is IMO an essential component of photography but then again it depends on what you are trying to achieve. The point is that you need to know what you are doing in order to achieve your goals. This might be a very basic knowledge or it may be in-depth highly precise and detailed technical knowledge. Depends.

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Again, it depends. Knowing your equipment and how it works is IMO an essential component of photography but then again it depends on what you are trying to achieve. The point is that you need to know what you are doing in order to achieve your goals. This might be a very basic knowledge or it may be in-depth highly precise and detailed technical knowledge. Depends.

Agree. Don‘t see a discrepancy to my post :)

 

Edit: ... especially since I phrased rather carefully „[...] OVERthinking the technical aspects may limit your photography.[...]“. Definitely not saying that you should not know your tools or the basics of the craft or that you may not even benefit from extremely detailed knowledge.There is, however, a danger of being preoccupied with and thus limited by these aspects.

Edited by schattenundlicht
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It needn't be. What is a 'correct' exposure? Should all images produce the same the rgb values for an 18% reflectance card? Take a look at the different ways in which digital ISO is measured. Consistency depends on utilising the same criteria for each camera. This needs checking before any conclusion is drawn.

 

 

That is not what I say. I just say that the brightness is the same. I do NOT say anything about correct exposure. I probably did not make myself clear enough.

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Unfortunately, that does not hold true in the digital world, where the values are undefined and ISO just a quantification of amplification.

 

Hm. I do not fully understand this reply. Do you say that ISO is just undefined? Just a figure? Like the volume on a radio that could go from 1 to 5 or from 0 to 100? Indeed the ISO is responsible for a defined amplification to have the picture the same brightness in comparison to other cameras even different sensor sizes. It is a specific value (per square mm) and not an absolute one. DxO measures that ISO value and indicates a deviation from camera value to real value. Yes I know that many do not like DxO here. By no means I want to start that discussion.

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