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02-04-2015, 12:22 PM   #211
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QuoteOriginally posted by clackers Quote
Not fot exposure.

F2.8 is f2.8 - no getting round it. :-)
I am talking about total amount of light. Bigger surface=more light for same shutterspeed/aperture. But let's start an equivalence debate......

02-04-2015, 12:27 PM - 3 Likes   #212
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QuoteOriginally posted by D1N0 Quote
I am talking about total amount of light. Bigger surface=more light for same shutterspeed/aperture. But let's start an equivalence debate......
Or ... let's not! :-D
02-04-2015, 12:46 PM - 1 Like   #213
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f/2.8 is a lens feature. Total light captured is a sensor (film) feature. So, f/2.8 is still f/2.8.
02-04-2015, 12:53 PM   #214
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if Ricoh US are quick to release we should se something here in about two hours:

Press Releases - RICOH Imaging

02-04-2015, 12:53 PM   #215
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QuoteOriginally posted by asahi man Quote
That's the point,for the hundreds of time :-)
And I prefer the body system,maximal optical quality and durability is only with a fix and stabil lens group.
My preference is the same as yours,
but Pentax chose not to go that route in the digital 645 cameras,
despite the sensor being smaller than the film frame,
and therefore well within the coverage of the heritage lenses.
02-04-2015, 12:56 PM   #216
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The problem wasn't the coverage, but the sensor's size/weight.
02-04-2015, 01:02 PM   #217
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QuoteOriginally posted by Kunzite Quote
The problem wasn't the coverage, but the sensor's size/weight.
mistral75 was invoking the behavior of vintage Minolta glass.

BTW, in terms of future-proofing the system,
can anyone tell us how the weight of a BSI sensor
compares with the weight of a traditional CMOS sensor?
02-04-2015, 01:09 PM   #218
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Let me clarify - with the 645D, AFAIK the reason for going with in-lens SR was the sensor weight, not the lens coverage.

Mistral75 is talking about Sony in-body stabilization working, on FF, with old lenses - as a proof that it can be done. I agree with him; the supposition that Pentax lenses won't work with in-body SR is completely unfounded.

02-04-2015, 01:09 PM   #219
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QuoteOriginally posted by lytrytyr Quote
mistral75 was invoking the behavior of vintage Minolta glass.
Kunzite was referring to the 645Z sensor (justifying ILIS for 645 lenses), not the 135 K-mount sensor. Apparently none of the switches on the new lenses has to do with OS. Mistral75 also corrected an errant and sarcastic Reply I made yesterday. In truth, why would Pentax not master IBIS for the FF sensor before they released the camera? IBIS is their hallmark.
02-04-2015, 01:11 PM   #220
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QuoteOriginally posted by clackers Quote
Not for exposure.

F2.8 is f2.8 - no getting round it. :-)
Correct exposure is a combination of the incoming light from the scene, the apperture, shutter speed and sensitivity and of course the artistic vision (low key, highkey...)

Idealy one has perfect sensor and lenses and choose the apperture strictly for the deph of field control and shuter speed only for movement control. Sensitivity being the adjustement to adapt to the light of the scene.

To know when it is more appropriate for proper exposure to act on the lighting of the scene), the apperture, the sensitivity or the shutter speed is really is part of the photographer responsability.

An apperture number alone is completely abstract and meaningless.
02-04-2015, 01:13 PM   #221
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QuoteOriginally posted by D1N0 Quote
I am talking about total amount of light. Bigger surface=more light for same shutterspeed/aperture. But let's start an equivalence debate......

But total amount of light is just not important in any way...

lets compare the DA*55 1.4 and sigma 35mm 1.4

we stick the DA55 on a full frame camera with the settings ISO=100 shutter=1/100 aperture=1.4
and we stick the 35mm on an APSC camera with identical settings

Apart from the fact that these lenses perform a little different and that 55 and 35mm does not give exactly the same field of view you would never be able to tell them apart by looking at the pictures and the amount of light.

So what difference does it make?

Where the difference can be noted is when it comes to bokeh. The full format camera will have a shorter Depth of field making the bokeh in the foreground and background more pronounced.

Also each pixel is bigger, that means that each pixel recieves more light than each pixel on a APSC since they are squeezed tighter together. The bigger pixel size on FF means that you also have a lower "dead space" to light capturing area on the sensor ratio. These both make the sensor better att filtering out noise.
02-04-2015, 01:21 PM   #222
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I will purposely print/display images at different sizes and resolutions, watch them from different sizes and crop each of them randomly just to make this... thing irrelevant.
D1N0, please; let's not transform this topic into yet another useless debate.
02-04-2015, 01:26 PM   #223
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QuoteOriginally posted by Kunzite Quote
I will purposely print/display images at different sizes and resolutions, watch them from different sizes and crop each of them randomly just to make this... thing irrelevant.
D1N0, please; let's not transform this topic into yet another useless debate.
I said the E-word. from that moment on it was beyond my control. (but a FF viewfinder is brighter) .
02-04-2015, 01:27 PM   #224
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That brighter, bigger viewfinder might be the only slightly rational reason to buy the FF, in my case.
02-04-2015, 01:29 PM   #225
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QuoteOriginally posted by discharged Quote
But total amount of light is just not important in any way...

lets compare the DA*55 1.4 and sigma 35mm 1.4

we stick the DA55 on a full frame camera with the settings ISO=100 shutter=1/100 aperture=1.4
and we stick the 35mm on an APSC camera with identical settings

Apart from the fact that these lenses perform a little different and that 55 and 35mm does not give exactly the same field of view you would never be able to tell them apart by looking at the pictures and the amount of light.

So what difference does it make?
Noticably, 99.9% of the time thoses settings (iso 100, 1/100, f/1.4) will not bring a correct exposure and make for a very bad photo over or under exposed. So you'll need to change some settings, be it apperture, sensitivity, shutter speed... Or the lighting to get an interresting photo.

But, independantly of exposure, apperture of f/1.4 will be many time a wrong apperture with too much or not enough deph of field.
And 1/100s will be many time a wrong shutter time, with too much or not enough movement captured.

We speak endlessly of the true meaning of a real apperture while it is just one parameter, no different, no more important than the others

Last edited by Nicolas06; 02-04-2015 at 01:39 PM.
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