[Deni]

I engaged in a sort of talk with one of the best known photographers here in Albania, which happens to be the main photographer of the company I work for.

In few words he says that his full frame canon is able to receive more light under the same circumstances than my humble k100d.

That is, safe focal length, same aperture, same aperture speed and same iso speed. Is that possible? He found it frustrating that I couldn't understand that much. I was telling him that I agree that the quality of the photo won't be the same, but the exposure has to be the same.

He also insisted that his several thousand euros lens captures more light under the same circumstances as my humble sigma 28-70 f/2.8 ex dg. The same as above, same light, same focal length, same aperture, same iso. Is that correct? I thought, like in the case with the camera, that the difference would be in quality and not exposure.

Who's right and amateur, me, or someone who is considered one of the best photographers in Albania?

[Lowell Goudge]

I engaged in a sort of talk with one of the best known photographers here in Albania, which happens to be the main photographer of the company I work for.

In few words he says that his full frame canon is able to receive more light under the same circumstances than my humble k100d.

That is, safe focal length, same aperture, same aperture speed and same iso speed. Is that possible? He found it frustrating that I couldn't understand that much. I was telling him that I agree that the quality of the photo won't be the same, but the exposure has to be the same.

Light is light, the same apature and focal length will give you the same exposure, because exposure is based upon the light intensity per square mm of surface area. But, I think what he means is that with a full frame sensor, a lens has a wider field of view.

He also insisted that his several thousand euros lens captures more light under the same circumstances as my humble sigma 28-70 f/2.8 ex dg. The same as above, same light, same focal length, same aperture, same iso. Is that correct? I thought, like in the case with the camera, that the difference would be in quality and not exposure.

This is an interesting point, where I think he believes the expensive lenses have lower losses in the glass. I recall years ago, a photo magazine uses to publish the true apature, under test conditions, against setting. this may be what he is getting at, but in principle F2.8 is F2.8 regardless of who makes the lens

Who's right and amateur, me, or someone who is considered one of the best photographers in Albania?

In my view, what you are coming up against is simply the attitude that since he pays more for his equipment it is far superior to yours. Don't wory about it, and don't let it bother you. just go on and continue using your camera, to take the images you like.

If you want to continue this discussion with him, ask him for the mathematical proof of his statements. That should give him pause

[Deni]

But, I think what he means is that with a full frame sensor, a lens has a wider field of view.

It wasn't about the wider field of view, it was specifically about exposure. His staement was that since the sensor in his camera was of a much higher quality it would be much more sensitive to light, everything else being the same, than a low cost sensor.

The way how this conversation started was that we have a soccer championship going on within the company and i was trying to shoot one of the matches. It was in the afternoon, and the lighting was far from perfect.

I asked him if he'd use a flash in those circumstances and he said absolutely not. He wouldn't need a flash since iso 3200 and f/2.8 aperture would do the trick.

To which I replied, that it was too dark even for iso3200 and f/2.8 and get a decent shutter speed.

He then tried to convince me that I shouldn't have shot at aperture priority and that I need a shutter speed of at least 1/400s (I know this), and that his multi thousand euro camera would have been able to perform where my camera sort of failed.

I'm including some photos of the match:

Available light

70mm
f/4.0
1/10s
iso 3200
+0.5ev
flash off



70mm
f/4.0
1/10s
iso 3200
+0.5ev
flash off




Then it got dark pretty fast

34mm
f/5.6
1/90s
iso 3200
flash on



70mm
f/4.5
1/90s
iso 3200
flash on

[procyon]

Even many pros just don't get the theory behind what they do.
Especially with digital cameras, you know all those bits and bytes and voltage gains and so on....
That's life.

Regarding the sensor sensitivity - many Canon DSLR-s have ISO values that are wrong by definition. See the Photographic tests sections of DPreview reviews for Canon cameras. They actually test whether the reported ISO really is that actually.

[Canada_Rockies]

To which I replied, that it was too dark even for iso3200 and f/2.8 and get a decent shutter speed.

He then tried to convince me that I shouldn't have shot at aperture priority and that I need a shutter speed of at least 1/400s (I know this), and that his multi thousand euro camera would have been able to perform where my camera sort of failed.

I have never understood this thinking. Quite simply, open the aperture to its widest, and you will get the highest possible shutter speed for the lighting conditions. The shutter speed will not be a constant 1/400 or whatever - it may vary from 1/250 to 1/1000 as the players change lighting conditions, but the shutter speed will be the absolute maximum available with the lens.

[rfortson]

The only thing I can think he may have been referring to is that the pixels on his full-frame sensor may be bigger than the pixels on your K100D (though your K100D isn't bad in this regard).

However, exposure is exposure. I think he was talking about sensitivity. Or, he was just an equipment snob. Everyone wants to have the biggest/fastest/most whatever.

[Matjazz]

I have tested *Ist DS against EOS 350D with same settings (sensitivity, aperture, time) and got equally exposed pictures. Various test report that Canon DSLRs have +1/3 gain in iso meaning that ISO100 is actually ISO125. But like I said looking at picture and histogram I couldn't tell the difference in exposure.
I'm sure that ISOxxx is means the same sensitivity on 350D and 5D and I really have no idea what the famous photographer is talking about.

[Douglas_of_Sweden]

I'd say this was a case of a bad combination of arrogance and ignorance.
Money can do a lot of things, but it cannot change that both cameras and all photons involved follows the same physics.
But I met this before among news-photographers thinking my Pentax cameras to be too small and light compared to their heavy Nikon cameras, and just because of that fact, their cameras must take better pictures...

[HGMonaro]

you need a bit of Aussie perspective... he's full of it*

...excluding any incorrect ISO measurement by Canon... anyone got a clue why they would do that? Wouldn't a company rather add an extra setting at the top end of the scale for bragging rights i.e. 3200 could be claimed as 3600 or whatever and used as a marketing point. If his Canon does have a higher sensitive sensor, then his shutter speeds could be slightly faster than yours to achieve correct exposure (at the same f-stop).

The actual f-stop of a lens if called a t-stop I think. Used by movie makers for critical exposure management, and by some really old Large Format lenses. All this is from distant memories from reading it somewhere on the 'net, so may not be accurate!!!

* self censored word substitution

[Donald]

"receive more light" no, not with similar lenses.

Larger sensor and more photosites on that sensor will convert more photonic energy to electrical signal, and therefore, in common casual discussion at a football game perhaps be referred to as your famous Albanian has done. Whether those differences result in better image is probably subjective, and on an image by image basis.

[SpecialK]

Your friend is stupid. End of post.

[bymy141]

Deni,

You are right, he is wrong (more or less...)

A camera with a bigger sensor has a bigger surface to work with.
In general, the photons received by the sensor initiate electrons to move around.
Electrons also move by themselves, mainly triggered by the ambient temperature; we call the signal generated by this noise.
The more pixel surface, the more photons, the more electrons you trigger, the more electric signal you have from the sensor.

The sensor pixel circuits are followed by a variable amplifier circuit (variable by your ISO setting, its like the volume knob on your radio).
However, the more you amplify the signal from the sensor, the more you also amplify the noise from the sensor.

This means that (generally speaking) a camera with bigger pixels has a better signal to noise ratio.
Assuming that his camera has the same amount of pixels and a FF sensor, these pixels will be much bigger.
So, his camera with ISO 100 needs less amplification than yours, therefore it shows less noise.

Unless, his number of pixels are much higher than yours. Leaving less surface per pixel, may bring back his s/n ratio to yours.
However, in that case his camera would have a better resolution.

That is all there is to it.

Other factors on noise are: sensor design, type of electronics (CCD vs CMOS vs NMOS etc), and last but not least sensor temperature.
His Canon will probably beat your Pentax here.

Next to that there is something called cross talk. It is one signal in the camera influencing the other. Many electric wires in the camera have high frequency signals that act like little radios. The main counter attack here is camera design physical and electrical.

So, at 1/250, f2.8 and ISO 100 on both cameras, your camera will show more or less the same picture.
And if you use a quality lens (like a FA 50, 1.4) it will be very hard to see the difference in quality between these two cameras.

- Bert

[ftpaddict]

What a load of crap.

[jeffkrol]

I have tested *Ist DS against EOS 350D with same settings (sensitivity, aperture, time) and got equally exposed pictures. Various test report that Canon DSLRs have +1/3 gain in iso meaning that ISO100 is actually ISO125. But like I said looking at picture and histogram I couldn't tell the difference in exposure.
I'm sure that ISOxxx is means the same sensitivity on 350D and 5D and I really have no idea what the famous photographer is talking about.

I find that odd. Doug Kerr and others have shown the "iso errors" of Canon. Shooting a "white wall" w/ most (I believe Canon has this changed in some current models) Canon's will give an exposure peak in the middle (127ish). Pentax and most Nikons and others would w/ the same aperature /shut speed/ lighting give you a peak at 110.
Articles by Doug Kerr
http://doug.kerr.home.att.net/pumpkin/Exposure_Calibration.pdf
So that leaves Canon with only the possibility of achieving their target
value of Hu/Hsat by using a non-standard rating of ISO sensitivity—a
rating that is about 0.74 that which would be determined under ISO
12232. In other words, the sensitivity that is designated “ISO 100” by
Canon would probably be rated at about ISO 135 under ISO 12232.
pg17-18
Your practical experience seems to contradict this. Not sure why though. Even RH's "tests" show this and the main reason of his blabbering about Pentax "underexposing".

[Peter Zack]

I don't know enough to delve into the Canon ISO accuracy discussion but I'm sure it is close enough to the standard to be ignored for this discussion.

Deni, Just remember that if you were to use a hand held light meter to get the exposure readings, it will give you the aperture and shutter speeds for any given ISO setting.

You don't program in the sensor or film size into the meter. It reads the standard measurements for the 3 settings. So ISO 3200 is the same for all cameras regardless of format size or sensor and film. Aperture and shutter speeds are also the same standards.

At ISO 3200 or any other speed, his camera is no more sensitive than yours. It might be a little less noisy but that's all. He doesn't know what he's talking about or trying to baffle you with his "superior skills , knowledge and gear".