Before the rush

Before the rush
by evan-pak

Submit your Photo
Hall of Fame

Please participate in Meta
and help us grow.

Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Assuming that Canon 5D Mark II and Canon 60D both have the same processor, DIGIC 4 (single), why does the former shoots a better quality video? Better quality I mean the technical aspect, the video/compression itself.

Let's ignore the visual aspect like more shallow depth of field, for example.

I know 5D is a full-frame, but the video is 1920px wide. The 60D shoots 18MPx, which scaled down to 1920px wide should still look almost the same as if shot on full-frame initially, right?

Therefore, and this is my point:


If we exclude the depth of field and a better ISO handling from our equation, it's possible that the uncompressed input is the same on both cameras, right? Then, it goes to the digic 4 processor to be compressed, which is the same on both cameras. Yet, we end up with a better quality video on one of those cammeras. Why?

share|improve this question

closed as off-topic by dpollitt, inkista, Caleb, mattdm, TFuto Mar 2 at 14:40

This question appears to be off-topic. The users who voted to close gave this specific reason:

If this question can be reworded to fit the rules in the help center, please edit the question.

up vote 7 down vote accepted

The 5D Mk2 has a far larger sensor (because it's a full frame camera) and more pixels. My assumption would be the camera scales down the input to 1920x1080 so having more uncompressed data allows it to give a higher quality output.

If Andres's comment about it skipping lines whilst taking video is right, then the improvement in quality is more likely down solely to its lower pixel density. A lower pixel density means a bigger area per pixel, which means more light per pixel, more light per pixel means less amplification is required (amplification increases noise also)

share|improve this answer
Quality is related to surface area, not linear size. So while the diagonal is 1/3 larger the surface area is 2.25X bigger. Otherwise, the full-frame advantage would be much less. – Itai Jun 4 '11 at 15:35
Right you are @Itai, I'll update my answer – ChrisFletcher Jun 5 '11 at 15:35
Are you sure that the camera scales down the video? I thought the HD resolution was achieved by skipping lines. – Andres Jun 6 '11 at 1:41
I believe @Itai has it nailed. The 5DII has considerably more surface area, which provides a lot more information to interpolate when scaling down to final output size. I would be doubtful that sensor pixel rows are skipped...however I wouldn't be surprised if sRAW-style YCC encoding was used rather than normal bayer interpolation (which uses more bayer pixel data per pixel, and does not overlap pixel interpolation.) – jrista Jun 9 '11 at 3:01
This article:… Seems to suggest that line skipping did occur in older DSLRs – ChrisFletcher Nov 1 '11 at 13:00

Not the answer you're looking for? Browse other questions tagged or ask your own question.