TIFF format

[Dave McCormick]

I have noticed that my camera can shoot images in TIFF image format. The filesize is much larger than a JPG file. I don't know much about TIFF flies, so what good is shhoting in this format as apposed to JPEGs?

[Dave Mac]

I believe that Tiff (tagged image file format) is non lossy ie it does not loose image quality but of course it does not compress the file, so they are large. The jpeg format (joint photographic experts group, or something like that) is lossy. This means you loose detail with jpeg, and the more you compress the file (in PS for example), the more detail you loose. I believe that some photographic experts (that does not include me) shoot in RAW format and save the images in tiff
Cheers
Dave

[eccles]

Yep, Dave's pretty much got it. TIFF will give you better images with fewer unpleasant edge effects that jpgs can sometimes have. Just as important, if you need to tweak the levels or crop the picture, the resultant jpg copy loses detail whereas the TIFF does not. It's a good alternative where a camera doesn't produce raw images. You may find write times a bit slow when out taking photos so it's up to you to decide whether the improvements are worth the inconvenience.

[Dave McCormick]

Thanks for that. I only would use it if I wanted that great shot, normally would use JPG anyway, but for that best shot as I can get, I use TIFF as my camera does not support RAW.

[eccles]

TIFF is rather like a universal 'raw' anyway so there's not a lot lost by having one and not the other. Apparently, some publishers insist on TIFF, although when I've submitted pictures to the local Wildlife Trust magazine they've been quite happy with jpegs. But the loss thing with jpegs is valid, and every time you save a copy it degrades further, something that doesn't happen with TIFF.
I think TIFF works in a similar way as raw: In Photoshop, you don't actually change the raw original when making changes to levels, sharpness, contrast and saturation but just add the changes to the file. These additions are removable, leaving the original binary image unchanged.

[Dave Mac]

I don't shoot raw so this is not from experience, but my understanding is that it enables you to recover back to the original (as eccles said) but also when you process the image you can exaggerate different tonal ranges i.e. you can boost the detail in the highlight areas. For example, when you use jpeg for photographing a white butterfly, very often the white areas are burnt out. This can be corrected to some extent using raw (but of course not if you have totally overexposed the picture)
I don't use raw currently because of the huge file sizes and the extra processing required after the picture is taken but I will try it shortly due to the lack of highlight detail with jpeg which can be a pain.
Dave

[Malcolm Farrow]

Tiff files and RAW files are not the same and it's important to understand the most significant differences:

RAW files are sometimes described as a 'digital negative' and require dedicated software to open and manipulate. However, the software effectively leaves the original unchanged (it makes a kind of temporary file that contains any changes you make), so if you don't like what you've done, you can undo any changes or just start again. Once you export your RAW file, either as a TIFF or JPEG, you have a file whose quality will be affected permanently by any (saved) subsequent manipulation.

As others have said, TIFFs are uncompressed and do not show damage due to repeated manipulation and saving as readily as JPEGs do. But if you carry out too many heavy manipulations, a TIFF can show a loss of quality, particularly by loosing its smooth tonality. This can largely be avoided by using 16bit TIFFs, rather than 8bit - but these are big files!

JPEGs are compressed files. Effectively, the compression is achieved by throwing away information. High quality JPEGs usually throw away information that is either invisible or almost unnoticeable. Low quality, heavily compressed JPEG files begin to sacrifice detail and exhibit strange fringing effects. One important thing to know about JPEGs is that if you manipulate and re-save a JPEG you are adding additional compression to a file that has already been compressed - with obvious implications for image quality - certainly not something to do too often.

For my natural history work I shoot RAW and, once I'm happy with the file, I save it as a TIFF in my image library. I use them in that form for paper-based reproduction, but I convert them to JPEGs for online and non-critical applications. You need a lot of hard drive sapce to do this, but it's the best route if the best possible quality is your goal.

Most graphic designers I know re-save any JPEGs they receive as TIFFs - that way, should the file need to be changed at all (e.g sharpening, tone/colour adjustment, conversion to CMYK etc), no further information is lost.

Hope this explains things a bit.

Best wishes

Malc

[Malcolm Farrow]

I meant to add:

I think TIFF works in a similar way as raw: In Photoshop, you don't actually change the raw original when making changes to levels, sharpness, contrast and saturation but just add the changes to the file. These additions are removable, leaving the original binary image unchanged.

To the best of my knowledge, this is not correct - any saved changes to a TIFF file are permanent.

[Mike Young]

A good explanation Malcolm, I was going to add my ten penneth but you've explained it better than I would have done.