File types...confused?

[sherwoodman]

Hi, Being a newish starter in digital having to admit I have taken to it like a duck to water (certainly not missing the darkroom)..however I am looking for
a little of advice with regard to the different type of files I am encountering.
Any advice in understanding `files` would be much appreciated :shrug:

I have been very fortunate in being allowed to borrow a `Hasselblad` H1D..
for a couple of weeks..after downloading `Flexcolor`I was amazed the size
of files (3f) the camera produced...85 + meg..!!!

So not knowing the first thing about files I have to ask how...after very little
work in `Adobe`(no cropping) does this initial 85meg file after being saved as a Jpeg suddenly becomes just 8meg? am I losing any quality in this reduction Do I need to do anything special to maintain the quality this camera is capable of? and lastly do photofinishers accept any file type?


Thanks....

 

[photon]

JPEG is one of the "lossy" compression types, so Yes, you do lose quality, and the trick is to keep it to an unnoticeable amount. It can be difficult to avoid banding in a broad expanse of polarised sky, when the image is compressed.

TIFF is a lossless option and, even with the compressed options, the files will be a lot larger than JPEGs.

Welcome to TP

 

[Chaz Photos]

Well it hard to tell you in a few words but
You most likely taking a RAW file that is 16 bit (65536 tones for each colour RGB)
when you save a JPG it will be a 8bit (256 tones for each colour) and you have to strip out a lot, you do not need all this info as you can not see it all It good to have it to start with so you can work on the image to alter it.
Hope this goes some way to explaining it for you.

 

[photon]

Say you've got an area, all of the same colour. Instead of defining each pixel's position and colour, we can define the whole area and assign it just the one colour. That's a very simple example of compressing the data.

 

[tbm]

For maximum flexibility of future editing you want to save the file in an uncompressed or losslessly compressed 16 bit format. The original camera RAW, Tiff, and PSD are all lossless; the latter two can be 8 or 16 bit depending on your preference.

Use JPG for finished images for ease of viewing and small file sizes.

Increasing the compression of JPG files usually affects the size significantly but not the quality: I find 8/12 on photoshop a nice compromise (1/4 of file size, no visible loss of detail or artifacts that I can see). After that it's all downhill with diminishing gains in size for an increasing reduction in quality.

I think JPG and Tiff files are most popular amongst commercial printers..

 

[sherwoodman]

Many thanks to all for the quick response, I seem to be headed in the right direction..
Just ike to say a big thanks to the digital revolution in re-awakening my interest in photography...how thrilling it is being able to manipulate images to the third degree
all from the comfort of a computer chair....pure heaven..plus being able to draw information from a well informed forum..again many thanks for this information, also the warm welcome, I will be a regular visitor to the site...Regards Gordon..