D750 picture count (amount left on SD card)

METALBLADE

Hello guys!
Stupid question ive had my D750 for over a month now. Beautiful camera!! Question though, I have a 32GB SD card shooting in raw, on my D3300 in raw i get about 1200 pictures, and it tells me 1200. On the new D750 when looking at the top display it shows only 583. Now ive filled a memory card before taking pictures and got over 1000 to fit on the card. Its almost like for ever 2 i take, it takes 1 off the actually pictures left on the SD card. I was wondering. Has this been happening to other people? Is it just me? Wrong setting??

Thank you all so much for your time!

PB_PM

This is common, as the picture count is simply an estimate. The lower end bodies tend to give a closer picture count because they have less options for picture quality (bit rates etc).

METALBLADE

I see... I find it weird that it is off by almost exactly half though. Like ive gotten around 1200 out of the SD card. but it will only show at max 580ish

calengor

you've gotten 1200 on the card using the D750? or you've gotten 1200 on the card using another camera? It could be that whichever other camera you've been using has smaller file sizes.

PB_PM

I see... I find it weird that it is off by almost exactly half though. Like ive gotten around 1200 out of the SD card. but it will only show at max 580ish

Yes, that is typical for the higher end bodies. Strange I know, but that seems to be the case. Every higher end Nikon body I've owned has shown similar behaviour. The D300, D700 and D800 all do the same thing, usually showing an estimate of half or less of the actually possible capacity. I believe the estimate is based on the largest possible files that the camera can produce, but of course each file is never that size, so it is often possible to take more pictures than what is displayed. This is particularly true when photographing subjects with a smaller subset of colours.

Pistnbroke

Did some tests on the D800 used a 64 mb ( not GB) card said it would do 7 did 9jpeg
Then tried a 256mb card on fine jpeg ..said it would do 7 did 7 ..said full then over a minute allowed 5 more after each said full but a short wait counter showed 1 and did that 5 times.
strange. Probably goes into this delay mode as a warning you need a new card but does not stop you working immediatly.

METALBLADE

@PB_PM

Well i am glad im not the only one to experiences it. I havent ready anyone else talking about it and was like hmm.. maybe its just mine??

@calengor

Ive taken 1100 to 1200 pictures with the d750 but it only shows 580. With my D3300 Its the same except on the d3300 it shows 1200 and i get 1200 lol

I guess its just eh way of the higher end DSLRs. At least i know its an everyone thing not just a me thing.

John

This behavior is actually quite normal.

The reason behind it is how image data is stored.
Let me try to explain this in very simple terms.
Suppose you have 5 pixels in your image.

Then you might store your color information for each pixel individually.

What you get is this:

Pixel 1: R 125 G 125 B 125 (a grey pixel)

Pixel 2: R 125 G 125 B 125

Pixel 3: R 125 G 125 B 125

Pixel 4: R 125 G 125 B 125

Pixel 5: R 125 G 125 B 125



Suppose you use 8 bit per color channel then you will need 8 bit * 3 (number of channels) * 5 (number of pixels) = 120 bit to store your image



Of you could have a more efficient way to store this data:

Pixels 1 to 5: R 125 G 125 B 125

This will require 8bit *3 (number of channels) = 24 bits + a few bits to store the first and last pixel number of the sequence (pixel 1 and 5).
You might end up with a total of 40 bits.



The example above used a non-raw image but the same techniques can be used for raw images.
It illustrates how you can store the same data more efficiently (taking up less space).
When we store data in a smaller file size without losing any information we call this lossless compression.
When we store data in a smaller file size but sacrifice some information we call this lossy compression.

Now, how much your data can be compressed depends on your compression algorithms but also on the nature of your image. The more data is the same the more it can be compressed.

However, your camera doesn’t know what you’re going to photograph.
It might be a perfectly uniform grey card or it might be a field of flowers more colors, variations and gradations then you’d care to count.

So, what does your camera do?

It assumes the worst… It assumes that it will be unable to compress any of your images so it calculates the remaining amount of images as if every image used the maximum possible amount of storage.
I personally like this approach.
When the camera tells me that I have 100 shots remaining I know that I’ll be able to take 100.
Sure, I might be able to take 120 and those 20 are a nice bonus.
But I am 100% certain that I will be able to take 100.
If those 100 are insufficient (e.g. The bride is about to arrive at the church and I won’t have the chance to plug in another card during the ceremony) I can take actions accordingly.
Suppose the camera told me I still had 1000 images remaining and after 600 my card is full (right in the middle of the exchange of the rings) then I would be in trouble.

So, that’s why the camera calculates the remaining shots the way it does.
It plays safe and assumes the worst so you don’t get into trouble.

METALBLADE

@John

Thank you so much for the in depth response to my question! It defiantly makes sense now! Im still surprised that it is off by but about half, but as long as its normal on higher end camera, im okay with that! lol

heartyfisher

You may also want to check if your D3300 been set to compress to a fixed file size ie lossy compression. It gives consistent file sizes. you can do the same with you D750 too. ;-) if file sizes is important.

WRichardsPhotography

What I find annoying is that it doesn't show you the total number of pics you can take if you have 2 cards inserted but only the capacity of the first card. Once that's full, it starts showing the number of photo's available on the second card. Sometimes I get carried away and am shooting and then remember to check how many shots I have left to take and can't see easily if it's the number of shots left on the card in slot 1 or if it's the number of shots left on the card in slot 2. Why can't it be a total of the shots available for both cards? Anyone any ideas? So in love with this camera though...bliss!