Terrific work, Terry! I found that your tutorial is well laid out and easy to read.

I wonder what the difference would look like between the manual adjustments (in the tutorial) and automatic software version.

I am currently using Proshow Gold, and have found this acceptable. However, if the improvements are worthwhile, I may permanently change the way that I make slideshows.

Kind Regards,
Leigh

Nice effort.
Just a couple of questions.

Do you require the same Gamma adjustments for LCD and Plasma TV's as you do for CRTs?

Some reference to other DVD Slideshow authoring software might be useful. I know that you are using one particular product but the basic principles should apply to most similar products. Perhaps just a list of other relevent applications at the end in case people don't want to or can't use the application you are promoting.

Richard:

Good points. I will add some alternative slideshow creation programs to the instruction set.

On the matter of LCD/plasma gamma, I don't know. I only have the Loewe CRT widescreen to try my creations, and it so happens that most of the people to whom is send the DVD have much the same apparatus.

I would really appreciate any info that I can get from LCD/plasma owners. My guess is that there won't be much difference. In fact, given the innate tendency of LCds to extreme contrast and saturation it might even be necessary to wind the gamma down even more.

Anyone had any experience?

TL

Interesting process - but I suspect it's rather more complicated than necessary. A few comments for the debate:

* If you are able to do any photo editing in a slide show creation app (without going to an external app such as Photoshop), then the circle distortion issue should go away. Circle distortion clearly IS an issue for graphics created in Photoshop [or similar] which are then inserted into a video editing program. I have wrestled with this myself...

* The things to remember are: pictures in your digicam have square pixels; pictures on your computer screen may or may not have square pixels (a standard 1280 x 1024 LCD screen, for example, does not have square pixels, and some distortion may result); a standard 4:3 TV screen does not have square pixels; a 'widescreen' 16:9 TV picture has strongly rectangular pixels. It's easiest if the software can manage all this pixel incompatibility.

* Oh, and don't confuse the pixels on the physical screen with the pixels as stored on a DVD. A PAL DVD uses no more pixels to store a widescreen picture than it uses for narrow screen -- the display device has to manage the 'stretching out' of the pixels to make the picture display correctly. (This is why an anamorphically encoded widescreen DVD looks all 'squashed up' when played in 4:3 on a standard TV -- to see the correct picture aspect ratio, you need to 'letterbox' the picture.)

* If you don't change the dimensions of a picture in the editing program, and if you let the slide show creation program 'fit' the slides into your slide show, it should be possible to perform any image adjustments (colour, contrast, red eye, etc.) without introducing any circle distortion when the picture is inserted in the slide show program -- assuming that the slide show program is clever enough to adjust the image appropriately when rendering the MPEG stream. In my experience, most slide show programs manage this just fine.

* Of course, if you don't want the image to fill the screen, the slide show program's automatic 'fit to screen' will be annoying. Clearly you need to choose a slide show program that allows customised zooming (and cropping) in order to display the desired portion of the picture at the desired size.

* Custom pan and zoom (the Ken Burns effect) can be very powerful if used carefully (and judiciously). To produce good looking results, the slide show program needs to have the highest possible number of pixels to work with. If you scale images to 'TV screen dimensions' (in terms of number of pixels), then the customised pan and zoom results will be very poor (as the program must 'make up' the required number of pixels at each point in the zoom, to suit the TV screen). If I'm going to use P&Z, I always insert the largest possible image (highest number of pixels) into my slide show software so that there is more information to work with in order to achieve a smooth zoom. Even then, zooming into a picture with horizontal lines can produce some ugly flickering.

Personally, I find Picasa to be the simplest image adjustment program to use. Way simpler than Photoshop, and cheaper, too (free!). I adjust brightness, contrast, crop and red-eye in Picasa, then export the pictures (with no pixel scaling - remember, I want all the pixels possible if I'm going to P&Z).

I want 16:9 output and custom P&Z capability - which is a rare combinatin amongst slide show programs - so I use tools I already have at this point in the workflow. I use Ulead MediaStudio Pro to assemble the 'video' and to apply custom P&Z, transitions, etc. I render (AVI as it happens, but could easily be MPEG) out of MSP and then use Ulead DVD MovieFactory to assemble a DVD of slide shows created in MSP.

I get good results from this workflow, but I'm still hanging out for slideshow software Nirvana (ability to produce 16:9 AVI or MPEG output, ability to do brightness, contrast and red-eye all in the package, ability to have customised P&Z per photo). My research suggests that no currently available package includes all of these.

Richard.

Your Loewe TV also raises other issues to do with Gamma. You, like us obviously prefer the softer less saturated "European" image (we have a European made Philips CRT) but the vast majority of TV's in this country have the Japanese more colour saturated tubes. Changes made for the Loewe may not look so good on a Panasonic or Sony.

Richard:

I have tested slideshows on an LG and a Sony [both CRT] and found that, if anything, I need to wind the gamma down even further for the "Asian" tubes, which as you say are inherently high contrast and high saturation.

I have been hunting for some information on the effects of TV systems in order to understand some anomalies.

Specifically: the world of display devices is NTSC. PC monitors, camera LCDs and cameras themselves all produce images with a gamma of 2.2

The PAL system is inherently more contrasty -- 2.8 And PAL, as I imperfectly understand it, has a true black/black whereas NTSC has a Very Dark Grey black which can be adjusted - ergo, lower contrast.

This leads me to suspect that the uncorrected digital images probably look right - or close to right - on an NTSC TV. Which would explain why Americans consistently proclaim themselves satisfied with images displayed straight from camera onto TV.

And it makes sense, given that the world of displays is the creation of American and Japanese engineers.

I have read that video cameras are inherently PAL with the image converted to NTSC for display on that system. This would explain why videocam pictures do look OK on a PAL set straight from the camera. I have also read -- this may or may not be true -- that all studio videocams and apparatus, even in NTSC zones, are native PAL with the image down-converted for NTSC.

Can anyone shed any light on this?

All about gamma...

http://www.poynton.com/notes/colour_and_gamma/GammaFAQ.html#gamma

I'm dredging back into the past a bit here, and overlaying some assumptions about the present...

As I understand it, PAL and NTSC are both compromise systems developed to allow colour information (color for NTSC) to be included in a television signal in a manner that's compatible with the pre-existing black and white signal. That is, whatever needed to be added to include information about colour had to be added in such a way as to leave the transmitted signal compatible with existing black and white receivers.

In the old days (which are not so many days ago), TV cameras used CRTs to 'pick up' the image. Colour TV cameras used three CRTs (red, green and blue), and from the outputs of the three CRTs the various signal components (chrominance = colour and luminance = brightness) could be derived and encoded for transmission. I don't believe there was any fundamental reason why the CRT imaging sensors could be deemed to be either 'inherently PAL' or 'inherently NTSC'. If I'd been designing the cameras, I'd probably have tried to make the image sensore compatible with both formats (which would mainly involve having enough resolution to meet PAL's higher requirements - but there may be some other issues as to image fidelity), so that my factory could then just add different 'back ends' to produce the required output... assuming that my camera produced NTSC or PAL output at all.

I reckon in the broadcast world, mixing/editing/switching would have been in RGB or chrom/luma to the last possible point in the chain before encoding into PAL or NTSC -- only the scan rate and resolution would have been 'fixed'.

Anyway... I reckon that you'd find pretty much the same situation today for any broadcast cameras having analogue outputs -- but CRTs have been replaced by solid state sensors.

As I understand it, however, more and more broadcast work is done in the digital domain -- and at least in the capture/edit phase the ideas of PAL and NTSC are rapidly becoming obsolete. Cameras are chosen according to resolution (1080i? 720p? etc.) and frame rate (30/29.97 fps for NA, 25fps for rest of world), and the signal remains in the digital domain until it's encoded into PAL or NTSC for transmission to those still using analogue receivers.

It's probably not true that cameras (or any other part of the chain) are 'inherently PAL' or 'inherently NTSC' -- but I think it's LIKELY that most SD cameras these days contain common components capable of capturing PAL resolution -- if only for manufacturing cost reduction and simplicity.

(Now don't get me started on video resolutions, plasma screens, HD compatibility and all such issues.)

Richard (the other one)

I think that I understand that (sort of). :-)

To ease further confusion I will be RichardR from now on.

Terry,

I just thought I'd let you know that after looking for a slideshow program for some time I have purchased Memories on TV (Pro version). It's a great piece of software, very easy to use and it creates professional looking results.