Go Back   Steve's Digicams Forums > Digital Cameras (Point and Shoot) > Panasonic / Leica

Reply
 
Thread Tools Search this Thread
Old May 17, 2007, 12:49 AM   #1
Senior Member
 
trooplewis's Avatar
 
Join Date: Jan 2005
Posts: 578
Default

On my FZ5, if it is even mildly bright outiside, I always leave my exposure setting at -1/3 In auto bracket mode, -1/3 or even -2/3 always seems to be the best shot.

I saw in another thread that the FZ8 seems to work best and produce less noise without using a - exposure. Has the FZ improved since I bought the FZ5 in this regard? If I use a neutral exposure, most shots will have some blow-out in them. Thinking about the FZ8 and wondering (besides manual focus) what the upside would be.

By the way, my reason for wanting the FZ5 is that I shoot a lot of 12x zooms, and with almost 50% more pixels, I basically get an increase of 50% more zoom when cropped. So compared to my FZ5, an FZ8 would be the equivalent of an 18x zoom...I think. Thoughts?
trooplewis is offline   Reply With Quote
Sponsored Links
Old May 17, 2007, 8:34 AM   #2
Senior Member
 
genece's Avatar
 
Join Date: Jun 2003
Posts: 2,111
Default

I do not believe using a mius exposure is a good plan but if you use matrix metering it is about the only option for a correct exposure and that is what you are trying for.....and having a correct exposure is good, having an underexposed photo promotes noise.......but just because you set a minus exposure you were trying for the correct exposure ....so you are doing it correctly.

Now about the crop....the FZ8 has what panasonic calls Extended Optical zoom which does give you more soom I think if the camera is set to 5EZ it will give you about 550mm which is about 15X zoom and then it has a 3 EZ which give more.....I do not have a FZ8 so I am not sure of the numbers.

This is pretty much how the EZ works

http://panasonic.jp/support/global/c...ww/ans/ex.html

But as far as manually cropping I think the figures can be misleading.

The FZ 5 has 2660 pixels on the long side and the FZ8 has 3072 for a difference of only 400 pixels....not as much cropping difference as you may think.
genece is offline   Reply With Quote
Old May 18, 2007, 10:49 AM   #3
Senior Member
 
Join Date: Dec 2005
Posts: 167
Default

genece wrote:
Quote:
having a correct exposure is good, having an underexposed photo promotes noise......
Please will you explain how underexposed photos increase the noise? Underexposed photos are taken with faster shutter and in this way the CCD matrix will "work" less time and will have fewer noses. Am I wrong?

sunstorage is offline   Reply With Quote
Old May 19, 2007, 3:54 AM   #4
Member
 
Yogibear's Avatar
 
Join Date: Jul 2005
Posts: 76
Default

Quote:
Underexposed photos are taken with faster shutter and in this way the CCD matrix will "work" less time and will have fewer noses
Interesting remark. We all know, that photos taken in low light tend to be noisy and underexposed. Butthe question is,are underexposed photos noisy by default?

My answer is: no,unless the underexposure is so strong that the brightening up of the photo to normal levels shows thebase noise of the CCD. The noise in lowlight photos is indeed caused by the long exposure.

The beautiful thing about digital photgraphy is, that most questions of this kind can be easily answered by making some test photos. Here is a test row I made just now, all with the same shutter speed and aperture (1/125and f3.2), with flash correction set at -2, -1 and 0. These are strong center crops,all adjusted in brightness to approx identical normal levels.

The -2 exposure shows a lot of chromatic noise, both in the white and the black. But as you can see, there is hardly any differencebetween the -1 and 0exposure.


Personally, I always have theexposure adjustmentin my FZ20 and FZ5at -2/3, because I want to avoid blown-out highlights.


Attached Images
 
Yogibear is offline   Reply With Quote
Old May 19, 2007, 1:28 PM   #5
Senior Member
 
genece's Avatar
 
Join Date: Jun 2003
Posts: 2,111
Default

IMHO

Underexposing a photo creates noise, it is widely accepted that statement is true....

setting the exposure comp to a minus value is not necessarily under exposing a photo....but metering correctly may be better. (I can get lots of arguments on that statement ,but I believe it)

Flash comp and exposure comp is not the same.

But if you were to take 3 photos in raw ......one over exposed ,one normal and one under exposed......if you darken the over exposed photo to be the same as the normal one the noise will be very similar......but if you lighten the underexposed photo to be the same as the normal one the noise will be much worse especially in the darker areas.

You may not agree but its food for thought.

There are times when a minus exposure is a must in an auto mode. But I do not believe it is something that you should use all the time......but again thats only my opinion.

But if it works for you I would continue with what works.

genece is offline   Reply With Quote
Old May 19, 2007, 10:24 PM   #6
Senior Member
 
trooplewis's Avatar
 
Join Date: Jan 2005
Posts: 578
Default

Setting the default exposure (outdoor shots) on the FZ5 at -1/3 was sort of the standard recommended setting based on the experience of folks on this forum after that camera was introduced. a full -1 or -2 setting will change things a BUNCH, but I can attest to the fact that if I use 1/3 auto-bracketing in "P" mode outdoors with a neutral (0) setting, 95% of the time the -1/3 exposure is the best one.

Iin regards to this:
Quote:
The FZ 5 has 2660 pixels on the long side and the FZ8 has 3072 for a difference of only 400 pixels....not as much cropping difference as you may think.
My FZ5 has 5.0 million effective pixels, the new FZ8 has 7.38 million effective pixels. That is an increase of almost 50% (ok, actually about 48%) so effective zoom-thru-cropping (NOT digital zoom) is really almost 50% better. Or the equivalent of what would be 18x zoom on my FZ8. Is my logic faulty on this?
trooplewis is offline   Reply With Quote
Old May 20, 2007, 8:14 AM   #7
Senior Member
 
genece's Avatar
 
Join Date: Jun 2003
Posts: 2,111
Default

I am not sure faulty is not correct, but you have only 400 extra pixels on a side

It has been discussed if you wanted to double the ability to crop you would need to double the amout of pixels on each side....so to double the crop ability of the FZ5 you would need 5320 pixels on the long side and 3840 on the short side,and that seems to work out to increasing the MP count by 4 so a 20 mp camera would give a 100% increase and a 10mp camera may give 50%.....

I can only speak for my self but moving from a FZ10 (4mp)to a FZ20(5mp) to a FZ30(8mp) ....did not increase the cropability by 50%.....but it did increase.

I wish I could explain it better, but I should have paid more attention when I was in school , many years ago.
genece is offline   Reply With Quote
Old May 20, 2007, 6:40 PM   #8
Senior Member
 
trooplewis's Avatar
 
Join Date: Jan 2005
Posts: 578
Default

You sort of have to see it visually by graphing out , say a 3mp grid (2000x1500) and then adding 500 pixels on each axis, ending with 2500x2000, or 5mp.

It seems as though you are only adding 500 pixels on each side (which is sort of true) but you are adding it to the full length of both the X and the Y axis, and you really do get almost a 70 % increase in overall area. When you crop it down, to say an 800x600 resolution, the 70% increase is quite visible.
trooplewis is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 12:21 AM.