No, they're not on par with proper projectors that have a proper lens. But you have to ask yourself if your audience cares? A benefit of digital projection is that you don't have to worry so much about a blob of dust ruining a great shot. But the quality question . . . Well, you have to ask your audience about that.

I think the advantage of digital projection is you need only to carry a laptop which nowadays can weigh as low as 2 lbs and yet can carry more than 5000 pictures. Imagine dragging 5000 slides around and the hassles of loading them. A protable digital projector weighs about the same or slightly less than a slide projector but is less bulky and so also easier to carry around.

Using a laptop you can integrate your lecture and slide show with software like Powerpoint and this may allow you to lecture better and your photos to demonstrate your point better ( may be that is why it is called Powerpoint)

For those who sell photos another great advantage is if your client doesn't like your image you can tweak your photo to his liking on the spot with your laptop. Showing your client the process of tweaking and your willingness to tweak to suit his taste will probably help you to sell more photos. But then you need a bigger and faster laptop so your client doesn't have to sit and wait for too long.

So with all these advantages even though the quality may not be on par with the old slide show ( but then may not be that far you if you have a good setup) I think digital projection still has a lot to go for.

I think for projection of photos you don't need 16:9 ratio projector. The best portable projector available today should be a 1280*1024 DLP projector. DLP projector gives much better contrast than LCD ones and a better black. But if you are presentng in an illuminated room then you may still need a grey screen, like a Stewart Firehawk which will give you better black and contrast. Most portable projectors can manage 2000 or more Lux and so room darkness is not such a great problem.

There are many slide projecting softwares which will take care of the resolution issue and you don't have to worry too much about this. My suggestion is you keep two copies of each photo on your hard disk. The original RAW file and a jpeg file at 1280*1024. The jpeg file is for presentation in a slide show. Anything bigger than your projector's native resolution is a waste of space ( you have a bigger file) and time ( your computer has to downsize your file before the projection). The RAW file is for in case your client or student asks to see more details or you need to tweak the photo on site. The combined size would be about 10 MB and so you can easily carry 5000 photos on a 80 G hard disk and still have load of space for your OS, photoshop, RAW processing software and whatever else you need or fancy.

But before you jump into all these one thing you must make sure is that you know or can get somone to calibrate your projector ( and of course the monitors of your laptop and your desktop at home, and your printer if you are going to sell prints). Calibration is a BIG issue in the digital world. Without proper calibration your photos taken with great expertise and loving care may be presented in totally wrong color and dynamics. if you are really new to the game may be a Mac is a better choice than PC because Mac has better support for ICC profiles and so in case you cannot have custumn profiles created for your gears you can just use the profiles that the manufacturer supplies and you cannot be that far wrong.

You can give me an email - drcmma@netvigator.com if you need more advice on your digital setup ( actually it is all the way from your camera to your projector ) and I will be willing to help. It is not that complicated and yet not that simple either for a transformation from film to digital. But after you have gone through the hard part you will find that you are in a totally new world and you will wonder why it takes you so long to change.

I've often wondered what the actual manufacturing cost of these ridiculously expensive digital projectors is in relation to the retail price. They seem to be rich mens' toys. Affordable projectors tend to be low resolution (SVGA) and have a low contrast ratio.

For anyone who's concerned about colour accuracy (and most people on this forum probably are) the digital projector leaves a lot to be desired. However, as with all things digital, the price will come down as the quality goes up and the sheer convenience, portability and flexibility of the digital projector will leave the slide projector for dead.

A main hurdle seems to be resolution. The Holy Grail of the video enthusiast is a projector that meets the highest HDTV standard of 1920x1080p. How does this compare with an uncompressed digital image of 3000x2000p from a $1000 Canon 300D? ???

Clearly still images need more resolution that moving ones, so Ray's question is important. Remember that 35mm movies use the original 35mm frame dimensions of 24x18mm ("single frame", later renamed "half frame"). The wider modern aspect ratios are often achieved by cropping (though sometimes the image is optically compressed in the camera and expanded on projection with "wide screen" lenses), so the actual frame used is about 24x13.5mm. This assumes HDTV shape of 16:9, which is roughly correct. That small frame can look very good to most movie viewers.

Is it a coincidence that the matching of HDTV's 1920 pixels wide to a 24mm wide 35mm movie image is the same as matching 1920 pixels high to 24mm high 35mm still image, which is very close to the current dominant 2000 pixels or so of DSLR's?

One of the main reasons that are stopping my move to digital cameras is a fact that a large portion of my income comes from lectures accompanying slides shows.  As an Nikon shooter I will probably make the move into digital with the upcoming D2X, however I am concerned about future of my slides shows.

My question would be this:
Are digital projectors on par with regular projectors?  If so, which projectors should I be looking at?  What size of a file should I feed a digital projector if I want to get a high-quality (film quality) image?

Any information on this subject would be greatly appreciated.  I've noticed that this subject has gone untouched for longtime. Michael, I feel this subject deserves some attention, don't you?



PS I didn't know which forum to post this in.  I'm sorry if this is out of context.

The HDTV world is waiting for some (high-end but consumer) digital projectors that have native display capability of 1920x1080 - rear projections models are around and front projectors should soon be (you can get a big image on the screen but need good light control in the room).  They might be "portable" in the sense they can be taken along in a car to a lecture venue.  Remains to be seen how their black levels are, compared to the behemoth (150 lb and up!) 3 gun CRTs that are currently king of front projection at that resolution. The existing LCD and DLPs (which might be at the venue already) are not there either in black level or resolution, but it depends on YOUR demands of quality   If calibrated, they can produce some nice images, but nowhere near what a slide could present...

Andy

Are slide projectors fading away?

We might have to hope that the digital projectors are coming along in quality, cost and such, considering that Kodak has just announced that they will soon stop making slide projectors. They comment that "slide projectors have declined in usage, replaced by alternative projection technologies."

The press release is noted at the Imaging Resource web site
http://www.imaging-resource.com
Ironically, it appears with another one in which Kodak restates their commitment to film, to allay fears raised by their recently announced aggressive investment in digital imaging.

Ray,
I happen to be an HDTVer as well as a 10Der - If a 10D could handle 2000x3000 shooting 30 fps ad infinitum, we might stand a fairer comparison!  It can only do 3fps and only for a couple of seconds.  Plus the 10D only takes in photons, doesn't put them out!  Of course, the giant lightvalve units at rock concerts and such are not consumer units
The 1920x1080 rear projection TVs are available now and , for what they do, are already a terrific value at less than a 1Ds, and will likely drop in price faster than the 1Ds  :p .  The quality of such video can exceed that of "35mm" movies in the theater, since those are frequently third generation or worse prints, and the theater and projectionist quality are real additional variables..

Andy

Andy,
I'd definitely prefer a 1Ds. HDTV has interested me for a while (being slightly resolution obsessed like yourself ). Unfortunately, the last time I checked, the reality is something else.

Most displays that claim to be HDTV capable are merely HDTV compatible. They generally fail miserably in terms of horizontal resolution.

You say there are now true(?) 1920x1080 rear projection TVs available in the US. Well, that's encouraging. I wonder if they also operate on a 50HZ system ???  And is this 1920x1080i or 1920x1080p, and does the set have a DVI and/or VGA interface? I'm not sure a 3000x2000 image from a 10D is going to look at all impressive on an interlaced screen. However, if these sets are 1920x1080p at least you'd get about 1/3rd of the 10D picture information and about 1/6th of the 1Ds. A ways to go yet!

[quote=Ray,Sep. 28 2003,21:02][quote=AJSJones,Sep. 27 2003,22:50]. HDTV has interested me for a while (being slightly resolution obsessed like yourself ). Unfortunately, the last time I checked, the reality is something else.

You say there are now true(?) 1920x1080 rear projection TVs available in the US. Well, that's encouraging. I wonder if they also operate on a 50HZ system ???  And is this 1920x1080i or 1920x1080p, and does the set have a DVI and/or VGA interface? I'm not sure a 3000x2000 image from a 10D is going to look at all impressive on an interlaced screen. However, if these sets are 1920x1080p at least you'd get about 1/3rd of the 10D picture information and about 1/6th of the 1Ds. A ways to go yet![/quote]
Ray, That's why I was excited enough to mention the coming of  units with digital arrays that can do 1080p.  The first unit does not accept 1080p in, which is strange since its native display is just that - i.e. every input  is scaled up to that.  The engines are there and the front projectors are on the horizon  ::  Others soon will accept 1080p in - and there's no "convergence tweaking" needed for these displays.  
How close do you sit when viewing prints from a 10D?  The front projectors can easily create "prints" that are 80 inches wide (that's the size of my 3gun CRT image).  We'll need to be specifying FoV for viewing, like we do for the 10D lenses!

You're right, of course, that there's a way to go before we get 3000x2000 onto such a screen, but the 2 MP (x3 by the way!) 1920x1080 will make a great monitor when the DVI and VGA units come out...
Mitsubishi has an 82" rear projection unit that does it all but it's still $$$$

However, check out
http://www.e4engineering.com/item.asp?id=50014&type=news
if you want to see what's over the horizon, and
http://www.avsforum.com
for the latest in display devices "for Christmas"

These things may be closer than you think  (or even dared to dream of  :laugh: )

Andy