Which is the best image format to save

Discussion in 'Digital Discussion & Q&A' started by PJcam, Jan 2, 2018.

  1. PJcam

    PJcam No longer a newbie, moving up!

    Joined:
    Dec 26, 2017
    Messages:
    134
    Likes Received:
    38
    Location:
    UK
    Can others edit my Photos:
    Photos NOT OK to edit
    Interesting Keith but, only parts sinking in at this stage.

    I have changed my camera to Raw +L, I then just shop a general image of something near me to try see what is happening and try understand it more.

    Checking my view finder in the camera I am presented with the image just taken, pulling up the file details it tells me it is a Raw +L file. So far so good. So I removed the card and plugged into the laptop, I could see 2 files, a name.cr2 file and a name.jpg file. Looking at properties of the files I see the *.cr2 is 23.1mb and the *.jpg is 5.84mb, I can see straight away the massive difference on file size and memory card space they take up!

    I then opened Canon Digital Photo Professional 4, again I can see the 2 files and the setting the files were taken at, not aware of the Raw format, other than having seen the file format name, and many others, I have always used JPG files and if I wanted better images I would use TIFF files. Having got this far, I decided to go a little further and downloaded RawTherapee 5.3 FREE software for *.Raw files. Now I can see 'some' of the benefits but, need to back off a little for a while I think, I need to get back to fully understanding the photographic triangle and get that clearly fixed in my brain.

    There is so much to learn and the grey matter in the brain doesn't take things in as fast as they used to, but thanks for the information, suggestions and help.


     
    • Like Like x 1
  2. PJcam

    PJcam No longer a newbie, moving up!

    Joined:
    Dec 26, 2017
    Messages:
    134
    Likes Received:
    38
    Location:
    UK
    Can others edit my Photos:
    Photos NOT OK to edit
    I am able to see the Raw +L images in the camera viewer same as I could the JPG ones, I can also delete them from the viewer in the same way I could the JPG files. Maybe it is just that my camera allows me to do this, I am not sure as it is all new to me, all I know is mine is only a entry level camera, or that is how it is classified for marketing. It must have worked as I purchased it. :lol:
     
  3. KmH

    KmH Helping photographers learn to fish Supporting Member

    Joined:
    Apr 9, 2009
    Messages:
    40,536
    Likes Received:
    5,541
    Location:
    Iowa
    Can others edit my Photos:
    Photos OK to edit
    The camera cannot show a Raw file on the rear LCD.
    DSLR cameras make a JPEG Basic (smallest JPEG file) to show on the rear LCD. That JPEG Basic image is embedded into the Raw file and is also used to show in other applications, like your computer's file browser.
     
    • Useful Useful x 1
  4. Ysarex

    Ysarex Been spending a lot of time on here!

    Joined:
    Nov 27, 2011
    Messages:
    5,424
    Likes Received:
    2,396
    Location:
    St. Louis
    Can others edit my Photos:
    Photos OK to edit
    Your camera saves a 5184 x 3456 pixel image.
    So first, 5184 x 3456 = 17,915,904 or rounded off 18 megabytes or an 18 megapixel camera.
    In the raw format each pixel is assigned a bit depth of 14 -- 14 bits per pixel. That means we need more than 18 megabytes to store the raw file (8 bits in a byte). Allowing for the extra 6 bits 18 megabytes becomes 28 megabytes of required storage space. Fair to assume Canon applies some degree of lossless compression to reach the 23 megabyte file size.
    An RGB photo from your camera in JPEG format will be limited to 8 bits and so 18 megabytes uncompressed. JPEG's compression algorithm is responsible for the dramatic reduction in storage size. Data compression relies on the removal of redundancy. To create redundancy in your photo JPEG lays an 8 x 8 pixel grid over your photo. Photo data is dense and so each 64 pixel grid cell will likely contain 64 unique pixels -- can't compress. JPEG's job then is to alter the pixels inside a grid cell so that only 60% or 50% or 40% or even 30% are unique and the file compresses.

    With your camera set to Raw + L you're saving both files to the card with each photo you take.

    Careful with triangles. The "exposure triangle" as named is built on a false foundation. In the hands of youtubers and bloggers and facebookers it's amazing how that false assumption can be contorted into a confused labyrinth from which you may not escape.

    Exposure is a well understood and long since well defined photographic concept. We define exposure as the amount of light per unit area reaching the film/sensor. It is a function of a) the brightness of the ambient light b) time -- the shutter speed and c) any attenuation of the light through the lens typically expressed as f/stop. Notice what is not included in that definition. The triangle slip-up comes from a colloquial redefinition of the term exposure into the implied term "good exposure" or "correct exposure" or the "exposure I like." On top of that is added an incorrect understanding of ISO where it is common to assume that ISO adjustments alter the light sensitivity of the sensor/camera.

    The result of the above errors produces some specific confusion involving cause and effect. New photographers get the idea that high ISO values cause noise which is incorrect. High ISO values correlate with noise; correlate and cause are two very different things. More seriously new photographers get the false idea that adjusting the three legs of the triangle (shutter, f/stop, ISO) can produce an exposure equivalence. In other words ISO 100, 1/250 sec and f/8 is the same exposure as ISO 800, 1/1000 sec and f/11 -- the action stopping power of the shutter is different and DOF is different but the exposures are otherwise equivalent -- they're not.

    Take you're time -- it took me decades ;)

    Joe
     
    Last edited: Jan 3, 2018
    • Like Like x 3
  5. PJcam

    PJcam No longer a newbie, moving up!

    Joined:
    Dec 26, 2017
    Messages:
    134
    Likes Received:
    38
    Location:
    UK
    Can others edit my Photos:
    Photos NOT OK to edit
    Thanks Joe, a very detailed and clear message as always. The above also makes more sense now.

    I am picking up on the points, the rest needs, time, time to play, time to learn, repeat. We can read every book in a library but it will not give us 'experience'. We need both like we need two hands. :icon_cheers:
     
  6. PJcam

    PJcam No longer a newbie, moving up!

    Joined:
    Dec 26, 2017
    Messages:
    134
    Likes Received:
    38
    Location:
    UK
    Can others edit my Photos:
    Photos NOT OK to edit
    I can now see if I set at Raw +L the camera saved the 2 files, and if I change it to Raw it saves only the Raw file.

    Which is best, to just save the images as Raw files or to save both formats?

    I appreciate saving both formats uses more space, but putting memory space aside, what should I really save or what do I really need to save?
     
  7. Ysarex

    Ysarex Been spending a lot of time on here!

    Joined:
    Nov 27, 2011
    Messages:
    5,424
    Likes Received:
    2,396
    Location:
    St. Louis
    Can others edit my Photos:
    Photos OK to edit
    Kind of depends on if you have an immediate use for the JPEG. Even if you don't save the JPEG you still have it. So that we can preview our raw files the camera creates a JPEG (typically lower quality) and embeds that in the raw file. It's easy to extract: Instant JPEG from Raw so you can always get the JPEG later if you want to see if for some reason.

    Folks who quickly use the JPEGs on social media are likely to save the camera JPEGs rather than wait until they get the raw file processed. People like me on the other hand don't bother since all I care about is the raw file.

    If you decide to save the JPEG and hope to use it your behavior behind the camera is effected. The camera is equipped with a range of adjustments to tweak the JPEG output for better results under variable conditions. If you want the JPEG you'll want to look at those options; different profiles, contrast changes, white balance and so on. Shooting exclusively raw I ignore all that stuff. I don't even know what's available on my camera in that regard and couldn't care less as none of those settings have any effect on a raw file. So behind the camera I have less to worry about as my only concern is exposing the raw file. Flip side is I don't get an immediate photo that I can share and I'm committed to the processing work later.

    And let's not forget that some photographers deliberately shoot JPEG as their target final image. This is especially the case for journalists and event photographers whose job requires immediate delivery of the photos. They may decide the raw files isn't worth saving.

    Here's a little fly in the ointment that's commonly ignored by most folks: BIG GRAIN OF SALT HERE: When you save raw + JPEG you're typically producing sub-optimal raw files. It makes no sense at all to save the JPEGs if you're not going to expose to get a decent JPEG. If you do that then your raw file will commonly be a little underexposed. The sensor's highlight threshold is like a brick wall -- it hurts to run into it. So the camera engineers will design a little buffer into their systems such that a good-exposure JPEG is achieved from a raw file that is between 1/2 to one stop underexposed. Think if it as a safety buffer that keeps you from hitting that brick wall. It makes sense and considering the market for their cameras they're doing the right thing. But obsessive nut-jobs like me who decide they have to squeeze out every last little bit tend to work closer to the wall. As a result our JPEGs tend to be overexposed and unusable so not worth saving and yeah we hit the wall sometimes.

    Joe
     
    Last edited: Jan 4, 2018
    • Useful Useful x 2
  8. PJcam

    PJcam No longer a newbie, moving up!

    Joined:
    Dec 26, 2017
    Messages:
    134
    Likes Received:
    38
    Location:
    UK
    Can others edit my Photos:
    Photos NOT OK to edit
    I am never in a rush with files and prefer to edit on the laptop. I don't do social media.

    I have downloaded and extracted the suggested program file, the conversion of a file from Raw to Jpg is so easy.
    There is therefore no need to take up space on the memory card saving two formats in the camera.

    Thank you Joe
     
  9. vintagesnaps

    vintagesnaps Been spending a lot of time on here!

    Joined:
    Jan 13, 2013
    Messages:
    6,425
    Likes Received:
    1,873
    Location:
    US
    Can others edit my Photos:
    Photos NOT OK to edit
    Joe's paragraph that starts 'Exposure is...' seems to be a good explanation of it. I agree about the youtubers, etc.; I've been a photographer forever (or so it seems) and I don't think I've seen a video yet that I'd recommend. If anything, it seems like people might do well to unlearn a lot of what they 'learned'! lol

    I think you might do well to save for now, because later you may want to come back and see what you did as you develop more understanding of photography. Then down the road you could clear out a lot that was practice that you don't need to save.

    Your explanation of what you did seems like you're getting the hang of it. Hope you keep enjoying photography.
     
    • Like Like x 2
  10. PJcam

    PJcam No longer a newbie, moving up!

    Joined:
    Dec 26, 2017
    Messages:
    134
    Likes Received:
    38
    Location:
    UK
    Can others edit my Photos:
    Photos NOT OK to edit
    I totally agree with what you say, I have playing with Av, Tv and Manual modes mainly, setting the camera then tweaking aperture and shutter speeds, sometimes ISO, and saving to computer to view what I have done, these and more are saved in a learning folder, they will all be deleted. Same with learning the Raw and Raw +L from the camera, until I knew what I was doing I would shoot, transfer to laptop and suss them out, then again delete them.

    I bit like starting a new job I guess, you makes notes in the early days, you will not need in days and weeks ahead. It helps speed up the learning curve. (for ma any way)

    Reading brings increased knowledge :icon_study:
    Trying out what we read speeds learning :icon_camera:
    Practice helps both :icon_study: :icon_camera:
    Experience comes with reading, learning, practising, (repeat), in a word it comes in 'time'

    Thanks for your comments vintagesnaps, long may we shoot, learn and enjoy our hobby.
     
  11. Fstop-

    Fstop- TPF Noob!

    Joined:
    Nov 15, 2017
    Messages:
    41
    Likes Received:
    7
    Can others edit my Photos:
    Photos NOT OK to edit
    I meant after I am done shooting when I transfer all the images to my PC, I can go tru the jpegs with a file browser and pick the ones I want to keep. This way I do not have to load them all into the catalog to view them, just the ones that make it to the second stage.

    I probably only keep 30%-20% of the images I shoot. My work flow is sift tru the dirt to find the stuff with gems in it. I do not want to spend much time on the dirt. Sifting tru jpegs is much faster.
     
  12. PJcam

    PJcam No longer a newbie, moving up!

    Joined:
    Dec 26, 2017
    Messages:
    134
    Likes Received:
    38
    Location:
    UK
    Can others edit my Photos:
    Photos NOT OK to edit


    20-30% to the second stage is good Fstop.

    I have saved JG, Raw +L and Raw, I have now settled with Raw only but at least I have tried each to suss out the best for me. I have the Canon software, Digital Photo Profession but for Raw I now use, FastStone Image Viewer and RawTherapee, and Instant Jpg from Raw (the important one although they all have their uses) All Free software.

    I don't have many images to sift through yet, that said, as I test the camera I do have stacks that I am experimenting with as I learn, these are batched in folders for easy deleting later. We have to have a system that works for us however we use our camera and images.

    Thanks for your help.
     
    Last edited: Jan 7, 2018

Share This Page