Messages

1

Technical Support / Re: CoC equivalent for motion blur?

« on: January 11, 2013, 03:38:18 PM »

Doing some more digging, it seems like there's at least (old) precedent for this.

From Wikipedia:
The common 1/100 inch COC limit has been applied to blur other than defocus blur. For example, Wall (1889, 92) says:
"To find how quickly a shutter must act to take an object in motion that there may be a circle of confusion less than 1/100in. in diameter, divide the distance of the object by 100 times the focus of the lens, and divide the rapidity of motion of object in inches per second by the results, when you have the longest duration of exposure in fraction of a second."
http://en.wikipedia.org/wiki/Circle_of_confusion_diameter_limit#Wall_1889

Would still appreciate any insight that others may have into this, FWIW.

Thanks,
-dh

2

Technical Support / CoC equivalent for motion blur?

« on: January 11, 2013, 02:08:58 PM »

Hi all,

A bit of a theoretical question, rather than truly tech support... but figured this was the best place for it. I was thinking about whether there's some way of calculating minimum shutter speed for a moving camera or a moving object (or some combination of the two, obviously). When talking about depth-of-field, the circle of confusion (CoC) is used to quantify pixels in the image which are 'acceptably sharp'.

Is there any equivalent concept for motion blur -- i.e., how many pixels an object can move in-frame and still be considered 'frozen' or 'sharp'? It seems like the CoC measure should apply equally (i.e., CoC tells us what the maximum blurriness of a spot on the image that is still perceived as sharp), since we're still talking about blur, just from a different source (motion vs. aperture). Does it make sense to apply the same concept to motion blur, or am I way off base?

Thanks,
-dh

3

Lenses / Canon 24mm 2.8 IS - anyone have experience with this lens?

« on: December 19, 2012, 12:59:02 PM »

Hi all,

I'm considering getting the recently released Canon 24mm 2.8 IS prime, and was wondering if anyone has experience with this lens that they can share. I'm mostly planning on using this lens for landscapes, so the IS doesn't seem super-compelling but I'm not ready to make the jump in price to the 24L or the T/S.

Thanks,
-dh

4

Lenses / [moved] Canon 24mm 2.8 IS - anyone have experience with this lens?

« on: December 19, 2012, 12:54:56 PM »

[Sorry, just realized I posted in the wrong area... moving to Gear Talk]

5

Contests / Re: Gura Gear Giveaway!

« on: December 07, 2012, 01:40:56 AM »

Yes, please!

6

Software & Accessories / Re: Lightroom Presets.....

« on: November 21, 2012, 04:29:30 PM »

Same here -- I have never felt like I get any real value out of LR presets (other than simple automation-type stuff). Makes me wonder if I'm doing something wrong and spending too much time doing all my post-processing manually.

To that end -- how long do others typically spend post-processing photos? I typically edit out all my throwaway shots and then spend maybe 1-5 minutes per shot on the potential keepers.