How do you save a jpeg and still keep it at 6mb?

[Alison]

I shoot in RAW, I convert into TIF's then after I have finished editing I save them as jpeg's. They end up being 3mb or so (could it be because I have cropped the image?) but I need them to be 6mb without making the file bigger.
How on earth do I do that?! How can they go from 19mb to 3mb? I save the file at maximum quality.
Any help would be much appreciated. :thumbsup:

[mjs1973]

Alison,

I'm guessing that the 3mb size you are seeing is when your jpeg file is closed? Open the jpeg up and go to Image > Size and that will tell you how big your file is. When you save & close a jpeg, the file gets compressed alot, which makes for a much smaller file. I just did an experiment with a RAW file to get some numbers. When I open the RAW file in CS2 and go to Image > Size, it tells me I have a 36mb file. When I save and close that same file without any adjustment other than going from 16bit to 8bit, my closed file size is a little over 5mb. When I ope that same jpeg back up and go to Image > Size, it tells me that my file is 18mb. (I lost half by converting from 16bit to 8bit)

Does that answer your question?

[Alison]

I'm so glad you saw this Michael.
It's coming up 22.9M that's right isn't it?
I am attaching a pic to make sure I am looking in the right place.

I have also been saving as 8 bits, seems that my Adobe has that set as default.

Thank you, so much, for your help

[agni76]

Alison, can I ask you why you chose to save the pics in tiff?
I even not saying now of the quality of the pic - on my opinion, its not better than jpeg with a little compression.. In this format isnt so convenient to redact any photo.

[mjs1973]

Yup, that's were I was looking. If you're saving as jpeg, you have to save as 8bit. You can't save a 16bit file as a jpeg.

[Alison]

Alison, can I ask you why you chose to save the pics in tiff?
I even not saying now of the quality of the pic - on my opinion, its not better than jpeg with a little compression.. In this format isnt so convenient to redact any photo.

Rawshooter essentials automatically saves as tif.
And from what I understand, I can keep going back to my tif image and editing it as many times as I like without losing quality.

Thank you sooooo much Michael! You're a diamond!

[another view]

You can save a TIFF as a 16-bit file (as long as the software lets you do this) and keep working on it and saving it all that you want without losing quality.

If you had an important image that you were working with, you might consider saving three file types of this same image. First, the RAW right out of the camera. If you ever decide to do something totally different or really just need to start over on the post-production, you've got the original to do it with. Second, save a TIFF file as a 16-bit "master" after all your post is done. I probably would do little if any sharpening and leave it at full size.

Finally, have your files for printing sized to whatever size you need and do the sharpening that the file requires. It can be different for different sized prints which is why I recommending not sharpening them in your master file. Jpeg's have to be 8-bit files by definition, but once you've done curves/levels in post you really don't need the extra information. Jpegs are easier to print because the file size is so much smaller, and you'll wind up with a very high quality print doing it this way.

[Alison]

Yeah that's what I do. Well, all but the 16bit part. I have, at times gone back to my raw file to start all over again.

I have been saving them correctly all along without realising it. But, I have been looking at the closed file size like Michael said.

[Ronnoco]

Yup, that's were I was looking. If you're saving as jpeg, you have to save as 8bit. You can't save a 16bit file as a jpeg.

Actually, I took a look at one at the information screen of one of my jpegs and it indicated:

16 bits per channel RGB and format JPEG

Unless, I am missing something, I appear to have saved a jpeg in 16 bits.

Ronnoco

[rzozaya1969]

Rawshooter essentials automatically saves as tif.
And from what I understand, I can keep going back to my tif image and editing it as many times as I like without losing quality.

Thank you sooooo much Michael! You're a diamond!

JPEG is a format that saves small files, but has some picture quality issues. If you see areas with the same color, or pretty similar, you'll see some artifacts. But, on most software you can set up how much compression you want to use for JPEG files. If you select a high quality-big size file, pictures are pretty good and can be modified several times. But when making smaller files, and then you want to change contrast, increase brightness or other stuff, you'll start to see the artifacts. So when saving JPEG files, choose a small amount of compression to keep your images intact.

I think that different software expresses this different, I use Jasc Paint Shop Pro 7.x, and you select the amount of compression, so 15 has a better quality than 45, for example. But I don't know if for Photoshop is the other way around, where 100 is a perfect image, and 90 would still be good, but 50 very low.

What you can do is take a TIF or RAW image, where you know they're intact, and save them with several settings, and then open the saved files and see how they were affected by JPEG compression. I usually save at 15 on Paint Shop Pro. If I'm just going to upload a pic to the internet, maybe 20 or 30 would do the trick (but I don't expect to modify the saved image afterward). In case I would need to modify something, I would open the original image, rather than the ultra compressed one.

Good luck