File Formats and image quality

[bobt]

What type of file format is the best as far as copying files or enlarging them without degrading the quality of the picture or image. Jpeg, Tga, Raw or another type? i know that Gif files are useless becouse they can handle only 256 colors.

[JTx]

Depends on how large you mean by enlarge. I use "fine" quality .jpeg on my camera and get very good quality 8x10's.

[country]

RAW is obviously best for everything if it is converted to 16 bit TIF. At that point, what you do in PS is non-destructive. RAW out of camera is 12bit. The converter bumps it to 16. If for workflow or storage reasons one shoots jpg, which is 8bit, shoot it at the cameras highest quality setting.

Any upsizing is highly dependent on the detail in the picture. People have less detail than images with a lot of foliage and as such will upsize better.

I am not sure why TIF option is included in camera options as it is 8bit usually, and a file size hog on camera media and I haven't heard of anyone using it in camera.

As to copying or moving files, doesn't matter. Thet are copied or moved intact. You can only resave jpgs a couple of times before they become prone to artifacting. Best thing is, however you shoot, (RAW or jpg), cull out the bad shots and save the original out of camera files that are left and never overwrite them. They are, in essence, your negatives.

country

[John Stutz]

Country is on the money. Here's my 2c too..

If quality is your primary goal, RAW is your only option. It captures exactly what hit the CCD without conversion. If you shoot JPG, then your camera will interpret the images and apply whatever settings you have made in your camera such as tone, white balance, etc, and then change the image and write it out in a lossy format. You really don't want your camera to make these adjustments, nor do you want to compress to a file format that loses data. You can do all this in PhotoShop much more accurately and without data loss. Any changes to JPG files will further compress and lose data, whereas saving in PS format will not. The drawback of course is that your image file sizes are much larger! But if you have a fetish for super large file sizes, then try TIFF. You won't get anything more than RAW, but your files will be gargantuan and take an extremely long time to write to your CF card.

As for enlarging... don't... unless you're shooting at 6.5 kilopixels (320x200) and you need to make it larger so people can see it on the web. But since that scennario is highly unlikely, there's no need to enlarge your images. If you want to print bigger, than simply instruct PhotoShop to take whatever pixels you have and print them at your desired size. It will enlarge for you and you'll maintain the highest quality. Otherwise you're just going through additional unnecessary conversions that will degrade your image quality.

[bobt]

Thanks for the camera info. I was also wondering if when you copy an image file off the internet in jpeg format is it better to store it in another format such as a tif. file or another file for use on my computer only for copying it or increasing the image size/ Thanks, Bob

[country]

Thanks for the camera info. I was also wondering if when you copy an image file off the internet in jpeg format is it better to store it in another format such as a tif. file or another file for use on my computer only for copying it or increasing the image size/ Thanks, Bob

When you copy or download an image from the internet, it will come down exact. If you decide to enlarge it, you can do so off the original jpg you brought into your computer as TIF will not add data to the jpg. If you are going to work on the image later in time that you enlarged, then you should save the enlarged to tiff which is lossless and as such no data is lost by resaving multiple times. Then when you have done what you want to the picture, save it as a very high quality jpg. If you simply want to enlarge with no future adjustments, then save as very high quality jpg. Same rule I mentioned in last response would apply here of always keeping the original intact.

country

[BigD]

I would suggest the site that John alreay mentioned, www.kenrockwell.com as he discusses this in-depth. I don't have time to shoot in RAW then tweak everything. I used to shoo tin Fine, but switched to Normal to hold more on my card when I see it makes no visible difference in normal prints. RAW is great if you don't shoot much and have the time to mess with it. I don't, so I am sticking with JPEG. LOL

[fivegrand]

Shoot RAW for photographs

Shoot jpeg for pictures

TIF is useless as a shooting format, the only people that care about TIFs are print houses (and most of them would rather have flattened or merged PSDs).

[BigD]

Shoot RAW for photographs

Shoot jpeg for pictures

TIF is useless as a shooting format, the only people that care about TIFs are print houses (and most of them would rather have flattened or merged PSDs).

Rockwell discusses this as well and has done extensive comparisons. There will be no way to tell on an 8x10 whether it had been shot in RAW or JPEG. Check his article out, may save ya a lot of time.

[country]

My take is a jpg will print fine at its native resolution. So an 8mp jpg would print high quality up to 8x10 prints - providing metering is accurate as is white balance. And highest quality JPG is used. A RAW file will allow you to claim somewhat overloaded highlights, a stop of shadow area as well as allow you to set your white balance in conversion. A jpg, being 8bit, can color shift when trying to adjust those two parameters. Whether that color shift is a problem, only the user can determine.
Their has to be something to RAW as Sports Illustrated and National Geographic photographers shoot exclusively RAW, with some of NG photographers still using film.
Personally, I prefer RAW as I think there is an advantage. However, when I have needed to burst shoot or shoot a high volume of pictures, I am comfortable with jpgs ability to save space on camera media. I think each can have their place, especially if one knows the final output it is going to go to (web or up to a poster size print).
One of my guides was:
http://www.ics.uci.edu/~eppstein/pix/rawvsjpg/

[BigD]

My take is a jpg will print fine at its native resolution. So an 8mp jpg would print high quality up to 8x10 prints - providing metering is accurate as is white balance. And highest quality JPG is used. A RAW file will allow you to claim somewhat overloaded highlights, a stop of shadow area as well as allow you to set your white balance in conversion. A jpg, being 8bit, can color shift when trying to adjust those two parameters. Whether that color shift is a problem, only the user can determine.
Their has to be something to RAW as Sports Illustrated and National Geographic photographers shoot exclusively RAW, with some of NG photographers still using film.
Personally, I prefer RAW as I think there is an advantage. However, when I have needed to burst shoot or shoot a high volume of pictures, I am comfortable with jpgs ability to save space on camera media. I think each can have their place, especially if one knows the final output it is going to go to (web or up to a poster size print).
One of my guides was:
http://www.ics.uci.edu/~eppstein/pix/rawvsjpg/


Hell, a 4MP file makes great 8x10's. Rockwell says he saw a poster size made by the Nikon D50 @ 6.1. The megapixel thing is over rated.

[bobt]

It's true then that if I copy my jpeg files many times that they lose information every time I recopy them but isn't true with tiff files?

[fivegrand]

It's true then that if I copy my jpeg files many times that they lose information every time I recopy them but isn't true with tiff files?

Bobt -

*Recopying* is different from *resaving*

The beauty (and curse) of digital imaging is that you can have as many perfect copies of a digital file as you'd like. JPEG is what's known as a "lossy" format (as I believe has been explained above) and data is lost every time you *save.* This doesn't happen when you *copy* or duplicate.

Doug -

It's true that megapixels aren't everything. In terms of quality, I'll concede that it's true that JPEGs print perfectly fine 8x10s out of an inkjet; for the most part, I don't care about 8x10 inch inkjet prints. I care about 40x60 canvas prints and 30x40 (or larger) dye sub prints. Ken Rockwell also states many times on his site that he's publishing his opinion; his opinion, while certainly valid, isn't the end-all be-all of imaging and there are other (and often diametrically opposed) opinions held by others.

Cheers

[BigD]

Bobt -

*Recopying* is different from *resaving*

The beauty (and curse) of digital imaging is that you can have as many perfect copies of a digital file as you'd like. JPEG is what's known as a "lossy" format (as I believe has been explained above) and data is lost every time you *save.* This doesn't happen when you *copy* or duplicate.

Doug -

It's true that megapixels aren't everything. In terms of quality, I'll concede that it's true that JPEGs print perfectly fine 8x10s out of an inkjet; for the most part, I don't care about 8x10 inch inkjet prints. I care about 40x60 canvas prints and 30x40 (or larger) dye sub prints. Ken Rockwell also states many times on his site that he's publishing his opinion; his opinion, while certainly valid, isn't the end-all be-all of imaging and there are other (and often diametrically opposed) opinions held by others.

Cheers

I don't print on inkjets, I use a lab geared to professional photographers. But I don't print the size you are talking. I have had one printed 20x24 from a 5 megapixel camera and it looks fantastic. Rockwell DOES write his opinion, but when you cannot tell by looking at a print any difference, well..... I am just sying my Nikon does VERY well what I need. If you are shooting for magazines, weddings, normal prints, etc., a 12 megapixel camera vs. 6-8 will really make no difference. It is more so the processor and the photographer. You have a different end in mind than I do.

[bobt]

The beauty (and curse) of digital imaging is that you can have as many perfect copies of a digital file as you'd like. JPEG is what's known as a "lossy" format (as I believe has been explained above) and data is lost every time you *save.* This doesn't happen when you *copy* or duplicate.

Doug -
Doug. Let me see if I've got this straight what you are saying. I am mostly keeping my images on my hard drive. No copying over to printer etc. When I download a jpeg image and save it on my hard drive there is a one-time lose of info from it. Every time I copy it to another h.d. or floppy and "save" it then there is a loss of info. Right so far? If I just copy it once from the web and review using irfanview thats o.k. Don't use irfanview to copy jpegs. Use tiff if I'm increasing image size etc. I'm still a little confused. Let me think about it a little while longer. by the way what do you think of irfanview or is there a better one on the web?

[TomNine]

Let me see if I've got this straight what you are saying. I am mostly keeping my images on my hard drive. No copying over to printer etc. When I download a jpeg image and save it on my hard drive there is a one-time lose of info from it. Every time I copy it to another h.d. or floppy and "save" it then there is a loss of info. Right so far? If I just copy it once from the web and review using irfanview thats o.k. Don't use irfanview to copy jpegs. Use tiff if I'm increasing image size etc. I'm still a little confused. Let me think about it a little while longer. by the way what do you think of irfanview or is there a better one on the web?

No, if you just copy the image there is no loss, it is the same file that you downloaded. The potential loss comes from when you bring it up with some sort of graphics program and "save" it from there. This is usually a good thing and part of the jpeg format's appeal, that it will produce smaller file sizes with a loss of information that you probably can't notice. If you can notice the difference you are probably compressing it too much.

If I understand your original question correctly, the "best" (i.e. most information) way to keep a file you download is to just leave it in its original format. You may be able to make it more appealing through processing and if you think you are getting better enlargements by converting them to tiff that is great, but you won't generate any new information, only lose it.

[bobt]

That pretty much answeres it for me guys. Thanks. What are some of the best image viewing softwares on the web for resizing, color tinting, gamma corrections etc. I use Irfanview. Some others any better Irfanview?

[BigD]

The beauty (and curse) of digital imaging is that you can have as many perfect copies of a digital file as you'd like. JPEG is what's known as a "lossy" format (as I believe has been explained above) and data is lost every time you *save.* This doesn't happen when you *copy* or duplicate.

Doug -
Doug. Let me see if I've got this straight what you are saying. I am mostly keeping my images on my hard drive. No copying over to printer etc. When I download a jpeg image and save it on my hard drive there is a one-time lose of info from it. Every time I copy it to another h.d. or floppy and "save" it then there is a loss of info. Right so far? If I just copy it once from the web and review using irfanview thats o.k. Don't use irfanview to copy jpegs. Use tiff if I'm increasing image size etc. I'm still a little confused. Let me think about it a little while longer. by the way what do you think of irfanview or is there a better one on the web?


Tom is correct on this. The originals I shoot that I have on my HD are the best quality. I copy those to CD usually. Those are then my originals. If I work with my images on my computer and resave I still always have my original file.

I love Irfanview and use it all the time to resize in batches. I also really like Microsoft Digital Image Suite Pro 10. Great program! Now if only I could learn how to batch watermark in PhotoShop CS2 I would be a happy camper. I just can't seem to get it right!

[Tre]

This whole thread is a train wreck.

Poor Jon.

Bobt - Save your pics in a master file that will remain undisturbed. When you manipulate an image in any way, with any program, be sure you use "save as" NOT "save" and then when you do "save as", save the image in a different folder that does NOT contain your 'master' images.

I use PhotoShop for everything, but there are a variety of consumer programs and freeware that are just as capable of meeting your needs.

Good luck to you.

*deep breath*

[bobt]

O.K. Tre. When I download a jpeg file I'm to save it in a master folder. Then I copy that jpeg to a sub-master folder. The files in this sub-master folder can be manipulated in any way. Gamma correction, resizing, color correction etc. Just don't touch or alter the files in the master folder except for copying to other folders. I think that's what your saying. Converting the jpegs in the sub-master folder to Tiff for enlarging, gamma correction etc. might be a good plan also? Tiff keeps all of the image info I've been told. Is that Right? That's an interesting distinction between 'save' and 'save as'. I wasn't aware of it. This is VERY complicated business. To me anyway! Thanks millions for the help.

[BigD]

O.K. Tre. When I download a jpeg file I'm to save it in a master folder. Then I copy that jpeg to a sub-master folder. The files in this sub-master folder can be manipulated in any way. Gamma correction, resizing, color correction etc. Just don't touch or alter the files in the master folder except for copying to other folders. I think that's what your saying. Converting the jpegs in the sub-master folder to Tiff for enlarging, gamma correction etc. might be a good plan also? Tiff keeps all of the image info I've been told. Is that Right? That's an interesting distinction between 'save' and 'save as'. I wasn't aware of it. This is VERY complicated business. To me anyway! Thanks millions for the help.


Not complicated, and you got it! :)

[country]

That pretty much answeres it for me guys. Thanks. What are some of the best image viewing softwares on the web for resizing, color tinting, gamma corrections etc. I use Irfanview. Some others any better Irfanview?

Faststone image viewer is a very good free viewer. It allows you to do those things you have mentioned, plus other things.

country

[bobt]

Hi Country. I downloaded Faststone image viewer and it is pretty good. I'm using it in conjunction with Irfanview. I don't know all of it's features yet so maybe in the future I can rely soley on it. One thing I did notice about it is that it's image magnifier seems to produce a much cleaner image under magnification than the others. Even cleaner than Irfanview.
My apologies to members of this forum and other forums. I got on a cleaning-up-of-my-posts rampage the other night after about two stiff belts of gin. What a stupid idea that was. I'm afraid I deleted way to many of my posts and left some holes in other peoples forums. I realized that it might be hard to follow some discussions without them. P.M.ed Genex [Gene] about it and asked if the deletes could be reversed. They probably can't. Sorry if this happened to cause any inconvenience to anyone. [bobt] Bob Taylor

[country]

Hi Country. I downloaded Faststone image viewer and it is pretty good. I'm using it in conjunction with Irfanview. I don't know all of it's features yet so maybe in the future I can rely soley on it. One thing I did notice about it is that it's image magnifier seems to produce a much cleaner image under magnification than the others. Even cleaner than Irfanview.
[bobt] Bob Taylor

I used Irfanview for a number of years, but tried Faststone a while back and preferred it.
If, at some point, you feel like taking a deeper plunge into the world of post processing, there is a freebie program called GIMP, also referred to as the poor mans Photoshop. It can be intimidating and has a reasonably stiff learning curve, depending on the depth of usage. If you want to check it out, don't forget to install the GTK+Runtime before the Gimp program.
country

[Titania]

I used Irfanview for a number of years, but tried Faststone a while back and preferred it.
If, at some point, you feel like taking a deeper plunge into the world of post processing, there is a freebie program called GIMP, also referred to as the poor mans Photoshop. It can be intimidating and has a reasonably stiff learning curve, depending on the depth of usage. If you want to check it out, don't forget to install the GTK+Runtime before the Gimp program.
country
How do all these programs compare to Photoshop?
I have played around with Nikon Capture 4 which I got with my D200 which has some useful tools when I have my camera connected to my PC but for image processing, I still prefer Photoshop mainly because I know it so well.
Nikon have done a great job making their software 'feel' like Photoshop though.
The only time I actually use the Nikon software is if I shoot in NEF format. 99 percent of the time, Jpeg, Large, Fine is more than adequate though.

[bobt]

I doubt if they measure up tp Photoshop Titania. I just downloaded Gimp and it does have a high learning curve. Irfanview suites my needs for now. How does Photoshop compare to irfanview. I imagine it does quite a bit more. I'll have to break down and buy Photoshop someday.
Love the pictures of you. Keep it up gal!

[Titania]

I doubt if they measure up tp Photoshop Titania. I just downloaded Gimp and it does have a high learning curve. Irfanview suites my needs for now. How does Photoshop compare to irfanview. I imagine it does quite a bit more. I'll have to break down and buy Photoshop someday.
Love the pictures of you. Keep it up gal!
Thanks Bob :)
I think it was Gimp I had a play around with a few years ago when I was experimenting with BeOS as an alternative OS to Win98. If it was the same program, I do remember a steep learning curve and ended up going back to Photoshop on Win 98!!

Here's one of my self timer shots. The lighting was a couple of 150 watt Par38 floods. The one on the right was softened by reflecting it off my wardrobe door. El Cheapo studio lights lol :D
I'd love to get a couple of SB800's soon though.

[bobt]

Great picture Titania. Thanks, Bob

[Titania]

Great picture Titania. Thanks, Bob
Thanks again Bob :D

[femalemusclefan]

Great picture Titania. Thanks, Bob

I'll second that! :)
Very impressive bicep peaks! :cool:

[Titania]

I'll second that! :)
Very impressive bicep peaks! :cool:
Thank you too FMfan :D

[bobt]

What are .png image files used for and is it any good to save images under the .png file format?

[country]

What are .png image files used for and is it any good to save images under the .png file format?

PNG was brought forth as a substitute for the GIF format.

TIF is recognized as better for photography and scanning. TIF can use a CYMK color space where PNG can't as well as other things.

I do not save anything in TIF, except through RAW conversion and once done in PS dump the TIF as it will have been saved in final output JPG. If I saved off the web there would be no advantage to saving in TIF, so that would be saved in jpg as it will save as it was posted. If I shoot in JPG, TIF will give me no advantage as it can't add what is not there to begin with.

A converted 3.5mb JPG file converted to a TIF became a 23.0mb file and it gained nothing in quality.

country