How is it when i save in the print module it is half the mb of the develop module
But this isn't a problem, it's normal.
Your original files, if raw, are 14-bit files.
The print module is probably saving JPG files; these are 8-bit files with compression.
That would easily be half the size.
Raw files are indeed 14 bit, but they are mono-channel, so a total of 14 bits. Jpgs are indeed 8 bits, but they are tri-channel 8 bits per channel, so a total of 24 bits. However, although most Raws are also slightly compressed, jpgs are much more compressed, even when the quality setting is at its highest, and this is probably the reason for the difference, if cropping and resampling are ruled out. N.B.: When saving to jpg in Print, the image is cropped to fit the paper size set in the printer driver and resampled to the set ppi.
Raw files are indeed 14 bit, but they are mono-channel, so a total of 14 bits. Jpgs are indeed 8 bits, but they are tri-channel 8 bits per channel, so a total of 24 bits.
You make it sound like JPGs contain more information than the corresponding RAW.
If things are as equal as possible there shouldn't be such a significant difference between a jpg file from the print module and a jpg from the Library module.
Assuming the original file is a raw file, export a jpg with dimensions of 800 pixels on the long edge (should give you and 800x600 image based on 35mm format)
Apply no sharpening, no keywords and leave Metadata set to All.
Then take the same image into the print module and print as jpg with Custom File Dimensions of 8in x6in and a File resolution of 100ppi. Again apply no sharpening.
In the finder there may be a small difference in weight of the file. In my case 370kb from Library and 340kb from Print.
Open the files in Photoshop and you should see practically no difference in image quality and if you invoke the Image Size dialog both files should be identical dimensions and Image Size (mb)
The difference in the finder record weights can be attributed to the metadata or RAW data inside the file. View the file in Photoshop and invoke the file info . File > File Info...
You'll see a large difference in the amount of data located in the RawData section.
So, to get a significant difference between files exported from the Library Module and the Print Module you will be changing compression specs (jpg quality) and sharpening specs.
I know of no benefits to printing a jpg versus exporting a jpg assuming no borders or overlays are required.
All i really want to do is put a border on with a caption at the bottom and save so that i can print more than one copy at full resolution.
I save an a4 size photo everything exactly the same baring the border I have even done it without the border still vast difference. This is going to be like algebra at school never could get that either and that was 40 years ago.
Logic to me says if you are saving in the same program using the same spec it should be the same.
But, please read the above discussion, when you save a JPG compression is applied. This makes the saved copy smaller.
Will a Watermark work for your caption or is the caption specific to each image (IE: from the caption field)
Let me know what specs you have set in the Print module and the specs you have in the export dialog.
I will try to reproduce
yes i accept that but i'm comparing jpgs not raw file to jpgs.
It is set up 100% Jpg at 300dpi the caption is just the name of place etc. But i have also just done a4 jpgs exactly the same 17mb on one 4 mb on the other