Pixel Aspect Ratio

[Jayell]

I've just switched from PSE (v7) to Photoshop CS5
Once in awhile when I open file with several layers in PS-CS5 .. that was created in PSE V7, I get the following message.

par-correction.JPG

So I click YES .. then I get the following message:

par-preview.JPG

Assuming I'm going to continue working on that file in PS-CS5 from now on .. I'm not sure what I'm supposed to do. I DO know how to turn off PAR Correction. But what's different between PSE and PS to cause this?

[Bob]

You get the second message when you open a file with a non-square pixel aspect ratio. It's just an informational message to alert you to the fact that pixel compensation is on. As far as I'm concerned, I can't see any quality difference between having it on and having it off. I would much rather have it on and see my circles as circles not ellipses and not stretch or compress the image horizontally. I always leave pixel compensation on.

I haven't used Photoshop Elements for some time, so I can't address why you might get that first message. I've never gotten it. I am curious as to what's going on. if you still have a psd that gives you that message, would it be possible to upload that (the original uncorrected file) to the gallery temporarily so I can take a look at it and see if I can spot something amiss?

Check the pixel aspect ratio that the corrected psd is using and see if it makes sense for the intended use of the file. If it looks correct, I wouldn't worry.

[momoffduty]

I get those messages when opening a DVD menu template to edit. The menus were all widescreen if that makes a difference. I haven't seen any problems on the burned disc.

[Jayell]

Thanks Bob & Cheryl. Sounds like doing nothing is the best solution.

if you still have a psd that gives you that message, would it be possible to upload that (the original uncorrected file) to the gallery

Next time I open one that I know I haven't made any changes to, I'll upload it, Bob.

[Bob]

No need to post a file, Jayell. Cheryl's mention of getting the message when opening a DVD template turned on the proverbial light bulb.

When CS4 was introduced, Adobe switched to a new definition for the standard pixel aspect ratio (PAR). For example, The NTSC SD PAR was 0.9 and the widescreen PAR was 1.20. The values under the new definition are 0.91 and 1.21 respectively. PAL PARs had a similar change (1.09 and 1.46 vs the older 1.07 and 1.42) When you open a file containing the old PAR value, that message will pop up. You would never guess it, but what that message is telling you is that it's offering to change the old PAR value to the new.

[Jayell]

Adobe switched to a new definition for the standard pixel aspect ratio (PAR)

Well, now I'm (even a little more) confused.
OK, but those numbers are all for video, right? If I choose any preset other than video, or just open up a jpg from my camera the default seems to be square/1.0. So I'm not understanding the connection to the PAR correction (or maybe I somehow changed the default along the way .. ?).

But speaking of video, should I be changing the PAR if I AM going to use an existing photo or graphic in video? I know there have been discussions on this before, but it all went over my head. I'll check some of the past threads for more understanding.

[momoffduty]

When CS4 was introduced, Adobe switched to a new definition for the standard pixel aspect ratio (PAR). For example, The NTSC SD PAR was 0.9 and the widescreen PAR was 1.20. The values under the new definition are 0.91 and 1.21 respectively. PAL PARs had a similar change (1.09 and 1.46 vs the older 1.07 and 1.42) When you open a file containing the old PAR value, that message will pop up. You would never guess it, but what that message is telling you is that it's offering to change the old PAR value to the new.

That extra decimal point gets you every time. Light bulb? Your avatar has a strong resemblance

Jayell, I have a table printed out and forgot where I got it. Maybe Bob has a link.
If you want to place a square pixel psd:
4:3 NTSC SD = 720x534
16:9 NTSC = 864x480
Those 2 examples will fit the screen. If you have graphics with transparent backgounds then there isn't any concern.

I think that is why some had problems with the fake camera in PrEl since Adobe had to have changed PrEl an extra decimal point even though it didn't show up in the UI panel info in PrEl.

[Jayell]

If you want to place a square pixel psd:

I don't really care about my photos filling the screen, since I normally crop them with odd dimensions (and I work mainly in high def) .. but was wondering about the square versus non-square pixels. I think I better go do some reading. This PAR stuff is still really confusing to me.

[momoffduty]

This PAR stuff is still really confusing to me.

This should help:
http://library.creativecow.net/articles ... adness.php

I posted a thread about PAR last year when I got AE. Totally confused myself with all of the info and lots of overthinking. Since I have been down this road, it may be easier if you have a specific task in mind and I can help with that.

And Bob is good at translating into plain English.

[Jayell]

This should help: http://library.creativecow.net/articles ... adness.php

I've just started reading the article, but looks like great info, Cheryl. I'll be back when I have more specific questions.