Rotating-- degrades image quality

[gorby]

If I'm not mistaken, doesn't rotating an image in photoshop (or anything else for that matter) degrade IQ slightly. Yet you see it done all the time, to fix crooked horizons among other things.

I'm just wondering what the thoughts are on this, considering everyone is always flapping on about "is this lens sharp?", "is this sharp?"-- yet I do see a bit of a degrade when rotation is used (pixel peeping my own images at 100%)

[Beau Hudspeth]

I always do my best to shoot the image straight the first time in order to keep from rotating it later in PP - and from what I have seen, you are correct. The image gets resampled and you do lose some detail.

But you have to think about it this way: how am I going to use the shot?

If it is for a large print, then it is best to shoot it right from the start.
If your going to display it on the web, it is not big deal since you will have to greatly reduce the final size anyway, which also resamples it.

Just ad the correct amount of sharpening, when all is said and done, and you should not be able to see that any rotation has occurred.

[gorby]

No, no, I agree with of course, if you are using for web, then big deal.

But I'm just wondering-- if we are to go a long with the 'sharp obsession' line of thinking that you see, how come no one bats an eye with rotating?


By the way there should've been a "?" in the thread title, I was sure I put one there!

[Beau Hudspeth]

... if we are to go a long with the 'sharp obsession' line of thinking that you see, how come no one bats an eye with rotating?I think that that is because: if you rotate, loss of image sharpness is just one of the things that comes with the process and is unavoidable - so why sweat it. And, as I said, it depends on the images use and also the style of the image.

If it does not need super-fine sharpness, but artistically it benefits greatly from the rotation, then the artistic quality wins over ultra-fine image detail.

It comes down to: if the shot was not spot-on in rotation on the original, what are you willing to live with to get the end result?