Hi,
that only shows how important it is to set the camera to Manual mode and
determine all the parameters from knowledge, such a we talked about
yesterday.
The same applies for focusing: set the camera to manual focus and apply
zone focusing at the hyper-focal distance.
As I said yesterday, "knowing is better than measuring", this applies to
exposure as well as focusing.
Joachim
On 02/12/15 11:06, Olaf Marzocchi wrote:
What I wrote applies not only to light metering but also auto-focus, as written by Joachim.
The same reasoning applies: it’s just a matter of checking the result and shooting again if needed.
Olaf
*From:*dh-photo-bounce@xxxxxxxxxxxxx [mailto:dh-photo-bounce@xxxxxxxxxxxxx] *On Behalf Of *Olaf Marzocchi
*Sent:* Wednesday, December 02, 2015 11:03 AM
*To:* dh-photo@xxxxxxxxxxxxx
*Subject:* [dh-photo] Re: old skool stuff
I was aware of it, but new cameras with different sensors and focusing technologies appeared since I bought my last polariser and I wonder if it those rules still apply.
For example, mirrorless cameras with contrast-detect autofocus do not deviate the incoming light with a mirror and they don’t have a phase detect chip. These should be able to use the cheaper and brighter linear polarisers (about 1 stop less light is blocked!).
http://www.dpreview.com/forums/thread/3538982
I wonder what would happen with the newest hybrid focusing systems that are using phase detect on the sensor itself.
In any case, from what I understand the circular polariser only avoids problems with light metering and this was important with film cameras: you had to wait for the development to see the photo and a roll usually has only 12-36 shots.
Since digital cameras now have the preview, checking the photo after the shot for correct exposure makes linear polarisers useful again: it is a matter of correcting the exposure and shooting again if it happens that the camera got the settings wrong.
Keeping this in mind, it should be possible save money by buying at a good price linear polarisers in the second-hand market from people who “update” them. Good polarisers can be expensive (see here for a comparison: http://www.lenstip.com/139.1-article-Polarizing_filters_test_2015.html )
Olaf
*From:*dh-photo-bounce@xxxxxxxxxxxxx <mailto:dh-photo-bounce@xxxxxxxxxxxxx> [mailto:dh-photo-bounce@xxxxxxxxxxxxx] *On Behalf Of *Joachim Seibert
*Sent:* Wednesday, December 02, 2015 12:43 AM
*To:* dh-photo@xxxxxxxxxxxxx <mailto:dh-photo@xxxxxxxxxxxxx>
*Subject:* [dh-photo] old skool stuff
Hi guys,
the last class (well, 2 1/2 classes actually) might have been a bit much. Sorry for that!
Despite me using electronic cameras too, I am one of those film guys (i.e. fossils).
Thinking all manual (focus, exposure etc.), I seemed to have overlooked the problems introduced by automation. To me, a pol-filter just suddenly was not available any longer... the same thing now was sold as a CPL (circular polarizer). Since the thing was still analyzing linear polarization, this did not make any sense to me (me thinking in film!).
Today, I learned something! It seems it is mandatory to convert the linear polarization (which was fine for the century of film) into circular polarization as to not confuse the sensors of the automated focus and exposure determinations. Here is what Wikipedia has to say about this:
"For modern cameras, a circular polarizer is typically used; this comprises firstly a linear polarizer which performs the artistic function just described, followed by a quarter-wave plate which further filters the now-linearly polarized light into circularly-polarised light before entering the camera. This additional step avoids problems with auto-focus and light-metering sensors within some cameras, which otherwise may not function reliably with a simple linear polariser."
It seems, with technology moving on, problems are introduced which were unknown in the past.
I learned even more: I definitely arrived in the stage of being a technological fossil. Anyway, being what I am, a fossil, the fact that automation in modern cameras keep having problems merely confirms my doubts about automation all together.
Kind regards,
Joachim
