How the camera creates JPEGs? and do Macbooks show JPEGs different to Windows?

dieselnutjob

Senior Member
I bought my D750 a couple of weeks ago, and a pair of fast 128Gb SD cards.
For the first time I started to mess with raw NEF format. I followed the advice to save to both cars in NEF+JPEG(Fine).
Last Sunday we went to Whipsnade zoo and had a play, and that evening had a look at the results.
I was rather surprised with what I saw.

For some of the photos (it seems to be the ones with less colour) I couldn't immediately see much difference.

However one shot in particular that had trees which had different coloured leaves the difference was quite striking.
I had deliberately underexposed the shot. It was getting late in the day and I got the feeling that the camera was trying to brighten up the image to make it not what it was, and there was a corner of nice blue sky that a nicer blue if I underexposed.

The JPEG version of the file seemed to have weaker colours, whilst those of the NEF image seemed "richer". This is without altering the image in any way. I am talking about a JPEG and NEF file of the same shot straight from the SD card.

Next I thought I would try and save the image on my computer as a JPEG from the raw NEF file to see if I could make a better job of it than Nikon. I was shocked to find that I could!

Firstly I opened the raw NEF image using RawTherapee and saved it to JPEG. The result was much that same as that that the D750 had produced.

Then I noticed the save dialogue had a "JPEG quality" slider and that it defaulted to 95%.
By sliding that to 100% the jpeg file was slightly bigger than the one that the Nikon had produced, and the colours were richer again.

So just when I thought I had been really clever, there is now another spanner in the works.

I am looking at the photos again just to make sure that I'm not talking rubbish, and now I can't see much difference! It's very weird. But now I think about it I'm pretty sure that it was a different laptop. Right now I am on a Lenovo T420s running Windows 10, but when I think about it when I noticed these differences I am pretty sure I was using an old Macbook Pro 17 running High Sierra.

So is it true that the D750 doesn't save JPEGs in as rich a way as a JPEG could be?
Is there a setting in the D750 to have JPEGs saved with 100% quality?
My understanding of raw files is that allows more processing and recovery, but for a given unprocessed file does the JPEG compression spoil the image even if you have no intention of processing it?
Do you need a Mac to be able to see the difference?

I'm not trying to start a JPEG vs RAW war, it's just that sometimes you need a JPEG, for example to post on a website. It would be nice if the JPEG out of the camera could be as nice as it can be and I'm a bit surprised with such an expensive camera that it isn't. Maybe I haven't set it up right....
 

Horoscope Fish

Senior Member
So is it true that the D750 doesn't save JPEGs in as rich a way as a JPEG could be?
Is there a setting in the D750 to have JPEGs saved with 100% quality?
My understanding of raw files is that allows more processing and recovery, but for a given unprocessed file does the JPEG compression spoil the image even if you have no intention of processing it?
Do you need a Mac to be able to see the difference?

I'm not trying to start a JPEG vs RAW war, it's just that sometimes you need a JPEG, for example to post on a website. It would be nice if the JPEG out of the camera could be as nice as it can be and I'm a bit surprised with such an expensive camera that it isn't. Maybe I haven't set it up right....
I'm going to address your specific questions because you're covering a LOT of territory with this post and a some of the questions you're asking would require very long, very technical answers.

For starters I shot with a D750 for years and I want to assure you it's capable of producing exceptional out of camera .JPG's. There are some options you may or may not be aware of that control how your D750 records .JPG images though. First are the settings for recording Basic, Normal or Fine .JPG's (see page 115 of the User Manual). These settings control how compressed the .JPG file is. Less compression means a larger file of course so if your goal is to get the best possible .JPG out of camera I suggest using the Fine quality setting.

Another setting that has much to do with how your out of camera .JPGs look is the Picture Profile selected (there are seven of these) and within each Picture Profile is a menu that allows you tweak that Profile for things like Saturation, Contrast, Clarity and Sharpness (see pages 165-167 of the User Manual). I happen to think all of these Profiles need tweaking, at the very least most of them can stand to have the Sharpness increased but the specifics vary from profile to profile. I suggest you experiment a little to find what suits you.

You can also install new Picture Profiles on your D750 if you want. They're free and you use them just like you would the ones that came preinstalled on your camera. Go to https://nikonpc.com/ and have a look. I don't shoot straight to .JPG very often, but when I do I have a couple of these that I prefer to use. It's just something to consider.

Another issue you may be running in to is that digital images will look different when viewed on different devices. I don't want to delve into this issue deeply but it isn't a Mac vs. PC thing, it's that different devices (laptops, desktops, tablets, phones, etc.) can and will display the exact same image differently.

And as for raw vs. .JPG in general, I'll just say those are two different tools. One is not better than another, they're just very, very different and it seems smart to me to know as much as I can about all the tools I have so I choose the right tool for the job at hand. When I want to take control of my images and process them I shoot raw and convert to .JPG as needed for things like posting online. That being said, many people choose to shoot AND process .JPG's but my personal take is that an out of camera .JPG has already been processed so I shouldn't need to process it myself. To my way of thinking that's the whole point of shooting .JPG; to avoid having to post-process. If I know from the outset I'm going to post-process why wouldn't I start with a raw file? But again, that's me and my way of thinking.
 
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dieselnutjob

Senior Member
On the under exposure of the trees picture, I took a shot with the exposure set to default on the camera and looking at the LCD screen on the camera decided it was too bright.

So I used the exposure compensation to set -1 EV (I think that what it's called) and took another shot.

That's the one in the photo above.

If I open that photo in Rawtherapee and brighten is +1 EV (so what the camera would have taken) then I still think that it's too bright.

I suppose the point is it was nothing to do with the laptop as I had already made the decision before it got anywhere near the laptop.
 

Dawg Pics

Senior Member
As far as the camera trying to brighten up your images I can think of maybe 2 things to check. Auto ISO, which will try to keep your images at proper exposure even if you are changing shutter speed or aperture or something in-camera called Active D-Lighting. I never use it, but I think it adjusts contrast or something to try to keep details in the shadows:confused: You can read about it. I have a MacBook Pro and iMac desktop computers, the LED screens are very bright and the color tends to be cooler unless you change it. You can get a SPYDER or other tool to try to calibrate your monitor brightness and color. I know my Dad always questioned my processing because well, we had differing taste in contrast, but also, I think I underexposed in processing due to the bright screen. LED vs LCD The images will look different on every monitor based on the monitor settings and type.

You are asking the right questions. Here you go. Great web-site. https://www.cambridgeincolour.com/photo-editing-tutorials.htm
 

Dawg Pics

Senior Member
Check your camera screen brightness as well. It may look brighter due to that.
I put my camera options to show "highlights" They will blink if they are blown. You can also take a look at your histogram and see if the entire image is exposing toward the right.

So you did a -1 EV to lower the exposure, then you changed it to +1 EV in post? That would make it look way more exposed. 2 stops, no?
 
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dieselnutjob

Senior Member
So you did a -1 EV to lower the exposure, then you changed it to +1 EV in post?

I did -1 EV on the camera.
I downloaded the NEF files to the laptop.
I did +1 EV in Rawtherapee and didn't like that so didn't save it.

The photo as shown above is the NEF file straight off the camera (so including the -1 EV), converted to JPEG and saved to flickr. No adjustments at all.
 

Horoscope Fish

Senior Member
I did -1 EV on the camera.
I downloaded the NEF files to the laptop.
I did +1 EV in Rawtherapee and didn't like that so didn't save it.

The photo as shown above is the NEF file straight off the camera (so including the -1 EV), converted to JPEG and saved to flickr. No adjustments at all.
I'd say it's clearly over-exposed and, just as importantly, severely lacking contrast. How was this raw file converted, by which I mean what software did you use to convert the raw file to .JPG?

It's a nice shot and totally salvageable with some light processing... Maybe something like this:

...
48972100182_47dd98cde0_b.jpg
 

WayneF

Senior Member
I am months too late, sorry. The initial image is a very nice image, but is shown here washed out more than necessary. A starting point now, adjusting the Photoshop Levels tool (CTRL L in Windows) in its default mode RGB (not individual channels), move middle slider to the right somewhat (maybe 0.66) to help substantially (adjust by eye, with its Preview ON). That middle slider is called a Gamma Multiplier (just meaning basically a great brightness tool, as it adds no risk of clipping either end). To the right reduces brightness ... and is a best way, far better than the old basic tool called Brightness.

But LCD monitors come from the factory set too bright, because bright helps sales. For photos, maybe add a monitor calibration tool to aid your judgement of the images.
 
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