fat pixels

[Coho]

I realize this has been covered before but not for a while: When I convert my

images from tif to jpeg for display on PN, the colours just lose life. I look

at my lively tif images, then look at the somewhat drab jpeg conversions and I

must agree perhaps I deserve those 3/3s I'm getting. Is there a better way to

make the fat pixel sing as a jpeg and bring life to my images on PN?

[emre]

Convert your images to sRGB before posting them (and search the archives).

[Coho]

thanks

[david_h._hartman]

David,<br>

<br>

If you are using Adobe ImageReady to convert you TIF/TIFF(s) to

JPG(s) I recommend trying a compression value of 75 and if the

image is to large in megapixels then try 43. I find that values

between but not including 75 and 43 produces poorer quality

images. I have ideas as to why this happens but I cant

explain it correctly or completely so I wont try.<br>

<br>

For best color on various displays: copy your image to a new file

and use Convert to profile... to convert it to sRGB.

Depending on your monitor calibration and what Photoshops (or

another programs) images are emulating you may need to

adjust the Hue and Saturation in Adobe ImageReady. If you are

using a program other than ImageReady experiment with various

compression values.<br>

<br>

You many not get the best gamma and mid tone saturation directly

from your camera or on conversion. These can be adjusted using

the Levels and Curves pallets. To increase mid tone contrast and

saturation you can pin or drag the 1/4 tone down slightly then

drag up the 3/4 tone. This increases the mid-tone contrast at the

expense of the high light and depending, to the shadow contrast.

This is a feature of conventional wet darkroom process. Indeed a

painter must do the same on canvas. It's not possible to depict

the actual values of most subjects, particularly a hard sunlight

one on a two dimensional surface. In theory a sheet of

photographic paper can reflect no more than 100% of the light

that falls on it nor less than 0%. In practice it's more like 107%

due to optical brighteners and perhaps as low as 5% in the

shadows. These are not test values but general values.<br>

<br>

Do NOT use Brightness and Contrast as these are lousy,

that is they cause loss of data. If you need to clip the image

some use Levels where you can control what you are doing both

visually and with the aid of the Histogram. Note that Auto Levels

and Auto Curves does some clipping.<br>

<br>

I suggest archiving almost all images (as shot) as unmodified NEF(s).

Edit the best, that is separate them from the mediocre. Later an

image that does not seem worth saving may have more value to you.

I speak from sad experience. Saving the also ran(s) is not as

space consuming as saving apparently unneeded slides and

negatives.<br>

<br>

Best,<br>

<br>

Dave Hartman.