new 50 1.2 $1600

carlk said:

You can do that. Have both panels (sensors) to be smaller than the
6" cut out (image circle) and see what you got. Please think if
you still have some ablity to do so.

Click to expand...

still wouldn't matter - one cell, same position on each panel, same amount of time=same amount of energy collected/converted

Man you get dumber by the second. Didn't you take physics? Or did you smoke too much weed in high school?

carlk said:

Daughare said:

Why don't you compare a large panel and a small one with a board
with a 6" wide circle cut out of it placed in front of each panel
and measure ONE cell. You will get the same amount of light
collection dumb@ss. Some people are as stupid as dirt.

--
http://www.markjanzenphotography.com
---Still looking for the perfect camera bag.............

Click to expand...

Click to expand...

100-300 f4L IS

hmm, now that is a nice idea in my opinion. I would go for that... it wouldn't be the monster that the Nikon 200-400 f4 VR is. I'd actually want to have both of those assuming image quality is spectacular.

Solar panel does collect photons and convert them to electrical current. The current output is proportional to the number of photons it collects. Large solar panel collects more photons and generates more electrical current. Even though light falls on one square millimeter area on the larger panel is the same as on the small panel.

In term of efficiecy we are only comparing sensor or solar panel of the same technology.

gml said:

carlk said:

It will. Just compare a large solar panel and a small one.

Click to expand...

Two panels will 'collect' the exact same amount of light if the
first one is twice smaller but has twice more sensitive photocells.
Collect is the wrong term, though. Solar panels 'convert' solar
energy into electricity, for example.
Remember, the key factors here are light intensity and the ability
of the photocells to measure/convert this light into
electricity/heat. A white sheet of paper will convert into heat
less solar energy that a black one. Ask Lay Jay how much bigger the
white needs to be in order to get the equivalent heat than the
black one

Click to expand...

Well I have a Ph.D in physics and never smoked anything funny. What have you?

There are a lot of bad examples floating around (as well as insults).

Lee, you need to communicate more clearly what you're trying to convey, because I'm now more confused because of the signal:noise and the line-by-line rebuttals; I think a clear, well-written statement, for lay-people would be in order. Mark, man, chill out. I think you need to have a bit of an open mind regarding what Lee is saying; he's not saying the f-stops are physically different, I believe, but that their equivalencies are much different than expected.

Please, can we just keep this civil? Some of us have been on the Web for over a decade, and this board is at times downright juvenile.

ljfinger said:

Francesca_ said:

What changes is the field of view. Focal length and f-stop do not
change.

Click to expand...

Indeed.

Lee Jay said:

It is only once the picture hits the sensor that it gets cropped,
i.e. a 50 mm 1.8 will show as a 50 mm 1.8 until the picture hits
the sensor and at that point gets cropped to the FOV of a 80 mm...
f1.8

The aperture does not change because it is not on a FF.

Click to expand...

Careful. Did you mean "aperture" or f-stop?

--
Lee Jay
(see profile for equipment)

Click to expand...

I did mean aperture. A 50 mm f1.8 lens is a lens that has a maximum aperture of 1.8.

Actually I know quite some optical physics, but the whole "50mm is now 80mm" talk confused me. But with your help, I get the picture.

I guess the problem is, that Canons "light calculations" that leads to the "ISO" is not that easy to understand.

IMO the "ISO" makes calculations for photographers easy, but hides the real physics (e.g. signal gain/SNR).

Anything about the "other one"..?

JP

Alfonso Bresciani said:

it's from a Canon mailing list (european). They saying that
22 mp new 1Ds and 50 1.2 will be out no doubts

Why a 50 and not a 24 1.2??
--
Alfonso Bresciani
P_o_m_p_o M_u_l_t_i_m_e_d_i_a
==============================
You will know fear...Then you will know pain.
Then you will use a Mac.
http://www.pompo.com/heli.html
http://www.pompo.com/neworleans.html
http://www.pompo.com/NoLaSkyline/

Click to expand...

--
http://www.onemodelplace.com/johnpaul

ljfinger said:

From what I've observed, it seems like many of those that want a
50/1.2 have 1.6 crop cameras. If the 50/1.2 is $1600, it's about
$1300 more than the 85/1.8. Since the 5D is probably about the
same amount more than the 30D, why not just get a 5D+85/1.8 (which
can behave like a 53/1.1 on a 1.6 crop camera) instead?

If you want the 50/1.2 for full-frame, then that's different but
I've always found 50mm to be a pretty boring focal length on
full-frame (shot for years with a 50/1.8 on my AE-1).

--
Lee Jay
(see profile for equipment)

Click to expand...

Me.. I use mine for commercial stuff all the time,.. my 50mm f1.4 is a nice lens,..but if the L is any better, I'd take it in a heart beat! It's a handy focal length lens on a FF body..

JP

--
http://www.onemodelplace.com/johnpaul

Alfonso Bresciani said:

with an "improved" IS. I forgot.

That should be good but I'm not so crazy about f4
--
Alfonso Bresciani
P_o_m_p_o M_u_l_t_i_m_e_d_i_a
==============================
You will know fear...Then you will know pain.
Then you will use a Mac.
http://www.pompo.com/heli.html
http://www.pompo.com/neworleans.html
http://www.pompo.com/NoLaSkyline/

Click to expand...

Hmm... I heard about something else... much better than that.. any word on "that"..?

JP

--
http://www.onemodelplace.com/johnpaul