Exporting images for 1080p HDTV display

<p>Hi,</p>

<p>I have been able to setup a DLNA server on my Linux RAID file-server. I am able to view media on my HDTV displays via my networked Blu-ray DVD players.</p>

<p>The primary question is, what are the appropriate pixel dimensions for exporting photos for watching on a 1080p device? My pictures are, for for the most part, in 3:2 landscape format, or 2:3 portrait format, or 1:1 square, as opposed to the 16:9 of the display. The displays are 73" or 37", I want to export to a size that works for both.</p>

<p>The secondary intent is not a question, but more a request for wisdom around this overall topic. Although my editing workstation is calibrated, my TVs, as of yet, are not. At some point, I am planning on following this: http://www.curtpalme.com/forum/viewtopic.php?t=10457. I am going to export as generic sRGB for now, but eventually I plan on reexporting using profiles I come up with after the calibration. Any advice on this topic is most welcome.</p>

<p>My tool of choice for now is LR 3 to export, although I might use ImageMagick if the need arises. Also, so far JPEG files are viewable through the Blu-ray players using the players default slide-show mode, so I am sticking with that. For best quality, are there any pros/cons to using the LR3 slideshow export to movie formats?</p>

<p>Thanks in advance for the help and advice!</p>

<p>Shash</p>

<p><strong>The primary question is, what are the appropriate pixel dimensions for exporting photos for watching on a 1080p device?</strong><br>

I will suggest that you leave them at there maximum size or what i usually do is to export them at 1024 x 780 72ppi (ppi at that point dont do anything..but im use to do it ) with a sRGB color profile. A generic recipe good for many type of projector / tv / web / email ....<strong><br /></strong></p>

<p><strong>I am going to export as generic sRGB for now, but eventually I plan on reexporting using profiles I come up with after the calibration. Any advice on this topic is most welcome.</strong><br>

you dont need to export or you dont want to export with a calibrated monitor profile.. a custom profile is for the monitor only.. and since you cant really have a monitor profile for your tv.. it is best just to *play* with the tv setting until you get a good image to your taste when you watch tv. Then when you view your image save as sRGB color spcae they will look good.</p>

<p><strong>For best quality, are there any pros/cons to using the LR3 slideshow export to movie formats?</strong><br>

Pro? easy to config since all is done in Lightroom.. Con? not really.. some will say that you dont ahve as much power to create the best slideshow.. something you could do with Fotomagico for example.. but for a simple slideshow with or without music Ligthroom is a very capable software and easy to use.<strong><br /></strong></p>

<p><strong><br /></strong></p>

<p>It's easy in Lightroom. Export the images to fit in a 1080 x 1960 pixel box. The images will be automatically downsampled so that the entire image fits, whether vertical or horizontal, regardless of the aspect ratio.</p>

<p>Thanks for responding, Patrick and Edward, most appreciated.</p>

<p>Patrick, I would have thought that given 1080 scan lines (or pixel rows), at least 1080 pixels would be warranted on the vertical? And then I'd go 1080x1080 for squares, and (1080x3/2)x1080, i.e., 1620x1080 for the 3:2. Am I right that you are suggesting the 1024x768 as a good compromise for event standard-definition TVs? I am really interested in 1080p HDTV, and in that case, is my 1620x1080 number OK?</p>

<p>Edward, along the same lines, I understand 1080 (or, I think I understand :-)), but what is the reasoning behind 1960? I am not questioning your recommendation, just trying to understand why.</p>

<p>1960 is the horizontal pixel size of 1080 HD.</p>

<p>If I don't intend to zoom in for a slide show I crop my pictures to that exact dimension (1080x1960) for viewing on my Panasonic 58" plasma, even when zooming I normally crop my 18 MP shots down to a more managable size. I have a Mac Pro hooked directly to the receiver/amp via hdmi (dcmi on the computer end of cable) and an optical audio cable for sound. When the TV and receiver are on the computer recognizes the TV as a second monitor and I set it to mirror and run Fotomagico slide shows one to one on the TV.</p>

<p>There are a number of reasons to downsize: I save slide show/TV pictures in seperate folders, so I don't want to double disk use. Sharpening is best done after cropping. Fotomagico is more responsive with smaller pictures and slide show file sizes are more managable.</p>

<p>I export as RGB jpg at high quality (10) and keep the adobe color space I normally use in Photoshop. For calibration on the TV I always leave it on the THX auto setting (optimized for movies) which looks pretty much perfect to my eye.</p>

<p>Thanks Jim, I understand now.</p>

<p>I guess for me the difference is that although I crop my pictures, my personal preference is to still stick to a 3:2, 2:3 or 1:1 aspect ratio post-crop. I guess that's the "retentive", left-brained engineer in me, everything must fit pre-defined categories :-). I understand that cropping to 1620x1080 would allow me to fill the screen completely, but, old habits die hard!</p>

<p>I do agree about down-sizing, and I too like to keep my slide-shows separate.</p>

<p>When you "resize to fit" in Photoshop or Lightroom, the image will be automatically resized (resampled) so that it fits in a box with those pixel dimensions. It doesn't matter if the image is vertical or horizontal, nor if you crop it. The only caveat is that the image won't be upsized if it is smaller than the specified box.</p>

<p>Because HD television has a 16:9 aspect ratio, images with a 3:2 ratio will have a dark space on either side for a horizontal (landscape) frame, and a much wider dark space on either side if the image is vertical. Since vertical images appear much smaller on a TV screen, you probably want to shoot most things in the horizontal position.</p>

<p>You have gotten some advice that is close but not correct. A <em>true</em> 1080p device is 1920 x 1080 pixels. A true 720p device is 1280 x 720 pixels. There have also been many televsions sold that are 1366x768 pixels, and even some with 1024x768 pixels but with a 16:9 aspect ratio (i.e., not square pixels). (Yes, there are some other oddball and cheapo device resolutions, includning TV's that are actually 16:10 / 8:5.)</p>

<p>Basically, assuming you do not want to leave the choices of how to crop and scale to the display device, and you have a true 1080p device, your choices are to crop to a 16:9 aspect ratio and then scale to 1920x1080; or scale your 3:2, 2:3, or 1:1 image so that its height is 1080 pixels, and then paste it into a (typically black, but you can use whatever) 1920x1080 pixel background.</p>

<p>I crop images to 16:9, scale them to 1920x1080, sharpen as seems appropriate for my TV and its settings (you may need to try some different levels), save them to a thumb drive, plug the thumb drive into the TV, and start my slide show. Looks great!</p>

<p>Re the statements which I think contain (relatively minor) errors:<br>

"export them at 1024 x 780" -- this is not the native resolution of any semi-high-def display of which I'm aware.<br>

"Export the images to fit in a 1080 x 1960 pixel box." - 1920, not 1960, right?<br>

"1960 is the horizontal pixel size of 1080 HD." - again, no, 1920 I think?</p>