Picture capacity

<p>I recently up graded both my working bodies with 32 mb cards and wonder why the capacity numbers are so different. The D300 reads 2,8K but the D3100 reads 3.7K even though it uses larger files.. Both are set to Large/Fine. <br>

I think I know the answer but would like to know if I am correct.<br>

The Capacity number is an estimate since each file is a different size depending on the content and the two camera bodies are probably using a different way to estimate it.</p>

<p>I guess you mean GB not MB?? Mind you I've still got some <em><strong>much</strong></em> bigger 64MB cards I'll happily swap!! I've even got a <strong>HUGE</strong> 128 MB Lexar card, that's worth 4 of yours.....:-)</p>

<p>I guess it's the computer <em><strong>estimate</strong></em> bit that's to 'fault'. How about the difference in RAW alone numbers?</p>

<p>Those are all conservative estimates, especially since you are shooting JPEG. Generally speaking, JPEG files from the D3100 should be larger since it is a 14MP camera vs. the 12MP D300.</p>

<p>But Shun, the camera 'Maths' estimate make it the other way around, ie reversed...???<br>

I guess if you were being ironic, you'd have made 'should' read '<em><strong>should'.... </strong></em>meaning their not!!</p>

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<p>But Shun, the camera 'Maths' estimate make it the other way around, ie reversed...???</p>

</blockquote>

<p>Exactly, You need to ask Nikon how they came up with such estimates.</p>

<p>Excuse my MB/GB<br>

The math is backwards. Oh well. If the combined photo.net don't know then nobody but Nikon knows. It is a modern miracle. <br>

BTW I love the 3100. It acts as my carryaround camera (High IQW and with kit lens it is light) and my second camera (with the 105 2.8 VR) on jobs.</p>

<p> </p>

<p>Errol, what does RAW say? How do you mean 'math backward', not relating to the d300 v d3100 capacity?</p>

<p>It's almost implying that the JPEG algorhythm in the more modern camera saves more space allowing more 'capacity'...?</p>

<p>Image size depend on what is on the image recorded in your camera. Before you shoot, the number of images available is a estimate...and no two different model camera bodies (from Nikon) are *programmed* to do the exact same thing.</p>

<p> </p>

<p>Did you format the cards in-camera before checking the capacity?</p>

<p>I have two D300s bodies with 8 gb Delkin 625x CombatFlash cards. I shoot JPG Fine and the meter shows 723 possible images each, but the other day I shot a philharmonic concert (I'm the staff photographer) and when I was done, I shot almost 2400 frames. Quite a difference from the estimate. I format the cards in the cameras.</p>

<p>Again, after your format a card on camera, the number of frames remaining is merely an estimate of how many frames you can capture in the current image format you have selected, based on the remaining capacity on that card.</p>

<p>If your format is uncompressed RAW, the estimate is usually quite accurate since the file size of uncompressed RAW is quite consistent. If you select a file format that involves compression, such as (lossless) compressed RAW and especially JPEG, the amount of compression possible will highly depend on the content of each image. For example, if an image contains a large area of blue sky or gary sky without details, that image can be compressed by a lot.</p>

<p>Since Nikon does not know what you are going to shoot, they can only give you an estimate of how many remaining frames you can capture with that card. They sure don't want to surprise you by telling you that you can capture another 100 images but you run out of card space after only 50. That is why Nikon gives a an extremely conservative estimate; you are pretty much guaranteed to be able to capture that many images as they estimate regardless of how complicated each image is, but in reality you can typically capture a lot more.</p>

<p>Apparently the way they estimate on the D300 is even more conservative than on the D3100.</p>

<p>My guess is that Nikon have realised that their earlier estimation algorithm was miles out, and that they've revised it on newer cameras to more accurately predict the number of pictures you'll actually get on a card.</p>

<p>My D700 is always out by <em>at least 50%</em> in it's RAW + Jpeg estimate on empty 8GB cards and above. The figure does get more accurate as the card fills up, but this sort of wild "guess" is not really acceptable, especially when my little old Konica-Minolta A2 can get it almost dead right from the outset.</p>

<p>Just a thought - I believe ISO settings influence estimated file size (the expectation is that high ISO images are noisier, and need more bytes to record the "grain" - at least, this is true of RAW; it's possible that noise reduction in JPEG and smearing of detail actually reverses this calculation). I would imagine that, even set to the same ISO, the noise profile of the two sensors might have an effect. Or it may just be that they tweaked the JPEG settings to suit the sensor. Or (if the actual files are larger for the D3100 as well as the pixel count difference) they may just have improved the estimation, or wanted to be more conservative on the "pro" camera and hit a better marketing number on the consumer model.</p>

<p>OK I always format cards after a gig. I tried looking at the results when both are set to raw each on a 32GB card<br>

D300 - 2.1K - 12MB<br>

D3100 - 1.8 - 14MB<br>

So the numbers make sense.<br>

There must be two different ways the cameras estimate the JPG capacities since here is those results for JPG, Fine, Large<br>

D300 - 2.8 - 12MB<br>

D3100- 3.7 - 14MB<br>

I know that the actual JPG shots can be about 1.5 times the shown amount.<br>

Still this seems strange.</p>

<p>There is one more setting to check. Nikon JPEGs can be optimized for quality or size. In other words, even both are JPEG fine, the size can still be different. Please verify that all settings are the same.</p>

<p>Errol, you might want to capture one JPEG each from the two cameras of the same scene. What are the respective file sizes? (Different scenes may lead to different JPEG sizes due to the among of details in each image.)</p>

<p>Don't get me wrong, I'm very happy I can shoot so much more than what is indicated. When I first saw the count, I thought I should have bought 16 gb cards, but now I'm not concerned at all.</p>