F-stop blues - being duped into fast lenses

Started Jul 4, 2012 | Discussions thread
Grevture Veteran Member • Posts: 4,187
The friendly athmosphere here is sometimes a bit overwhelming ... ;)

RedFox88 wrote:

Grevture wrote:

eNo wrote:

BTW, closer examination shows some higher MP cameras (7D) with less EV loss than lower MP (larger pixel pitch) ones (D70, D40), leading one to question the universality of the statement: "This loss seems to increase when the pixel size decreases, as shown on the figure below."

There are a number of factors involved, like microlens design and efficiency, and the depth of the light gathering "wells", or in other words the thickness of the layers of stuff between the light gathering parts of the sensor.

If you design a higher megapixel sensor with the same well depth as a lower megapixel sensor, it will be less efficient when some light comes at an angle (as with large apertures). But then a higher megapixel sensor can have a more modern design, meaning shallower wells, and also maybe more efficient microlenses.

When Sony recently introduced the new 24 megapixel 24x36 sensor used in A99 (which is probably in many respects quite similar to the sensor in the D600) they spoke about reducing the thickness of the stuff making the "wells", thus probably making this sensor less problematic with large apertures then for example the older 24 megapixel sensor design used in A900/A850 and D3x.

This is where a BSI design could come in handy, there you get very shallow wells. But a BSI design is probably still to expensive for 24x36, or even APS-C sensors, to make much sense - yet.

So you're a semiconductor engineer? Or do you just pretend to play one on here?

Nice to meet you too, sir

No, I am not a semiconductor engineer. And none of what I wrote above does require, nor imply such a level of knowledge. The things I brought up are actually pretty well accepted common knowledge.

Now, did you have anything constructive to add, or were you just having a cranky moment?

-- hide signature --

I don't suffer from insanity, I enjoy every moment of it!

By the way, film is not dead.
It just smell funny

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