K20D vs. K10D SDHC Capacity

stand.sure · 06-19-2009, 08:29 AM

Long time lurker here.

Just upgraded from K10D to K20D. Still have my K10D. I've noticed something about file sizes, and am interested if anyone knows what accounts for the following diparity.

When the k20D is set to 10 mb, "four star" (max) jpg quality, a 4GB card will hold 416 shots. Photos are 3872x2592, ~ 6.82 mb each. At "three stars" the capacity jumps to 693 shots. Photos are 3872x2592, ~ 4.41 mb each.

My K10D shoots 10 mb "three star" (max) jpg at 3872x2592, ~ 3.43 mb each, and this results in having about 827 shots per 4GB card.

Same 4GB card, formatted natively by the camera in use at the time. Same target and lighting conditions.

I want to stress that this is not an issue. I am simply interested in what accounts for the almost 3.4 mb difference between the K20D "fine" and the K10D "fine" images? This is an almost 100% increase in image size from K10D to K20D without the actual size changing. The one thing I did not look at was dpi...

s.s

Duck Dodgers · 06-19-2009, 08:34 AM

4-star is less compressed than 3-star, and the K20D's sensor is 50% larger.

lunelson · 06-19-2009, 11:38 AM

To elaborate, due to the way JPEG compression works, the more detail an image contains, the larger the resultant jpg will be. Since the K20D achieves 10mp resolution images by downsampling with a large sensor, the images have more details before compression than a 10mp file from the K10D.

GerryL · 06-19-2009, 02:04 PM

Was this an actual experience shooting till the card ran out or are you going by what the camera said was shots available when you inserted the memory card unused?
Predicted number of shots compared to the actual are different.

stand.sure · 06-19-2009, 04:05 PM

Originally posted by lunelson

To elaborate, due to the way JPEG compression works, the more detail an image contains, the larger the resultant jpg will be. Since the K20D achieves 10mp resolution images by downsampling with a large sensor, the images have more details before compression than a 10mp file from the K10D.

Thanks. As a technical person this is both understood and appreciated. Thanks!

Originally posted by GerryL

Was this an actual experience shooting till the card ran out or are you going by what the camera said was shots available when you inserted the memory card unused?
Predicted number of shots compared to the actual are different.

A little of both. yes I realized it was "predicted." The predication generally came truew within a small margin of error. Thanks!

s.s

06-19-2009, 08:29 AM	#1
stand.sure New Member Join Date: Jun 2009 Location: East Coast, United States Posts: 10	K20D vs. K10D SDHC Capacity Long time lurker here. Just upgraded from K10D to K20D. Still have my K10D. I've noticed something about file sizes, and am interested if anyone knows what accounts for the following diparity. When the k20D is set to 10 mb, "four star" (max) jpg quality, a 4GB card will hold 416 shots. Photos are 3872x2592, ~ 6.82 mb each. At "three stars" the capacity jumps to 693 shots. Photos are 3872x2592, ~ 4.41 mb each. My K10D shoots 10 mb "three star" (max) jpg at 3872x2592, ~ 3.43 mb each, and this results in having about 827 shots per 4GB card. Same 4GB card, formatted natively by the camera in use at the time. Same target and lighting conditions. I want to stress that this is not an issue. I am simply interested in what accounts for the almost 3.4 mb difference between the K20D "fine" and the K10D "fine" images? This is an almost 100% increase in image size from K10D to K20D without the actual size changing. The one thing I did not look at was dpi... s.s

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06-19-2009, 08:34 AM	#2
Duck Dodgers Veteran Member Join Date: Dec 2007 Location: in the 24½th Century! Photos: Gallery Posts: 439	4-star is less compressed than 3-star, and the K20D's sensor is 50% larger.

06-19-2009, 11:38 AM	#3
lunelson Forum Member Join Date: Sep 2007 Location: Missouri Posts: 80	To elaborate, due to the way JPEG compression works, the more detail an image contains, the larger the resultant jpg will be. Since the K20D achieves 10mp resolution images by downsampling with a large sensor, the images have more details before compression than a 10mp file from the K10D.

06-19-2009, 02:04 PM	#4
GerryL Veteran Member Join Date: Jan 2009 Location: CA Posts: 2,731	Was this an actual experience shooting till the card ran out or are you going by what the camera said was shots available when you inserted the memory card unused? Predicted number of shots compared to the actual are different.

06-19-2009, 04:05 PM	#5
stand.sure New Member Join Date: Jun 2009 Location: East Coast, United States Posts: 10 Original Poster	Originally posted by lunelson To elaborate, due to the way JPEG compression works, the more detail an image contains, the larger the resultant jpg will be. Since the K20D achieves 10mp resolution images by downsampling with a large sensor, the images have more details before compression than a 10mp file from the K10D. Thanks. As a technical person this is both understood and appreciated. Thanks! Originally posted by GerryL Was this an actual experience shooting till the card ran out or are you going by what the camera said was shots available when you inserted the memory card unused? Predicted number of shots compared to the actual are different. A little of both. yes I realized it was "predicted." The predication generally came truew within a small margin of error. Thanks! s.s

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