Projected image

bjake · 03-07-2012, 08:55 AM

Have no experience with projected images but am planning to do some shortly.Will a 4 mp image look decent on a 4'x4'
screen?Should they be lighter or darker than ones for Prints?
Thanks,
Jake

demp10 · 03-07-2012, 09:34 AM

If you have a calibrated home theater-type projector the images will look spectacular. Keep in mind that full HD is 1920x1080 or about 2MP. You'll be better off if you resize your images at that resolution on your computer using the best option (usually bi-cubic). Use TIFF or 100% Jpeg when possible.

The image will definitely look different from a print. It is the same principle as on a computer screen. It will have significantly more contrast with vibrant colors and bright highlights.

If you use though a business-class projector, mostly targeting text and graphics, the color gamut will be limited and most details in the highlights and shadows will be gone. Check to see if there is a "movie" mode and use that, or use something to calibrate it.Avoid, "text", "graphics", "presentation" or "bright" modes since they tend to increase contrast by reducing color details.

I routinely project images on a105" diagonal screen and they look great.

Marc Sabatella · 03-07-2012, 11:02 AM

I was shocked at how good 2MP images from my collection looked when projected even on a fairly basic projector. But these were images with limited color info to worry about losing (mostly high ISO concert images with strong tungsten/halogen lighting).

bjake · 03-07-2012, 12:23 PM

Excuse for being so uninformed on projected images but it is a completely new subject for me.I have no idea as to what type of projector will be used,have seen it used,seems to change colors toward the green cast on some images but good on others.Am I being advised to resize to 2mp for the projected images?
Thanks,
Jake

demp10 · 03-07-2012, 12:53 PM

Originally posted by bjake

Excuse for being so uninformed on projected images but it is a completely new subject for me.I have no idea as to what type of projector will be used,have seen it used,seems to change colors toward the green cast on some images but good on others.Am I being advised to resize to 2mp for the projected images?
Thanks,
Jake

Jake, it is always a good idea to resize the images for the targeted output. You do not know how a projector will scale down your images. It may use an interpolation algorithm or simply skip pixels. You have much better control on your computer. Besides, the projector will display the images faster since it does not have to spent time resizing. Just find out what the native resolution of the projector is and use that. If it is a home theater-type projector then most likely it will be 1280x720 or 1920x1080. If it is a business-type projector it may have one of the standard computer resolutions like 1024x768 or 800x600.

On the color cast, it is important to either calibrate the projector if possible, or use one of the display setting that produces natural images with smooth gray/color gradations. If the projector has an sRGB mode use that to start with. If you can set color temperature use 6,500 K or set custom Red-Green-Blue to get a neutral image. A simple test to judge color casts is to display a medium gray image which it should look gray. Any color hue will indicate that the white balance on the projector is not setup correctly.

You may be able to hook up the projector on a computer or DVD player and use a calibration DVD to set it right.

In any event you will be impressed with the overall quality of the displayed image.

bjake · 03-07-2012, 11:32 PM

Guess I must get in touch with the fellow who is showing the images and find out what size he needs.
Thanks all,
Jake

bjake · 03-08-2012, 03:58 PM

Checked with the ones doing the projecting,they wanted 1024x 768.That downsizing could be quite useful as big crop could leave one with a nice image to be projected.
Thanks,
Jake

RioRico · 03-08-2012, 08:30 PM

Historical notes: I read a pro's account from 1/2 century ago, when he was asked if 35mm frames could be enlarged to 20x30. He replied "Sure -- 20x30 FEET, not inches." Recall that in pre-digital days, commercial cine was shot on frames about 24x18mm, what we'd call 35mm half-frame, very close to the size of our APS-C sensors. And those frames were regularly projected onto screens 30x45 feet or larger.

The trick here is that images will look good in very great enlargement, so long as they aren't inspected too closely. Those cine frames were normally viewed from some distance away -- folks in the front row at a theater probably weren't pixel-peeping the action, eh? I can take a 912x1216 shot from my 1.1mpx Sony DSC-P20 P&S (circa 2001) and enlarge it to 9x12 feet -- and as long as it's viewed from 15+ feet away, it looks fine.

So, keep the audience at a distance, and all will be well. No necking in the front rows, now...

03-07-2012, 08:55 AM	#1
bjake Veteran Member Join Date: Mar 2011 Location: Eastern Kentucky Posts: 416	Projected image Have no experience with projected images but am planning to do some shortly.Will a 4 mp image look decent on a 4'x4' screen?Should they be lighter or darker than ones for Prints? Thanks, Jake

03-08-2012, 03:58 PM	#7
bjake Veteran Member Join Date: Mar 2011 Location: Eastern Kentucky Posts: 416 Original Poster	Why do I need 12mp? Checked with the ones doing the projecting,they wanted 1024x 768.That downsizing could be quite useful as big crop could leave one with a nice image to be projected. Thanks, Jake

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03-07-2012, 09:34 AM	#2
demp10 Veteran Member Join Date: Jun 2011 Location: Atlanta Photos: Albums Posts: 602	If you have a calibrated home theater-type projector the images will look spectacular. Keep in mind that full HD is 1920x1080 or about 2MP. You'll be better off if you resize your images at that resolution on your computer using the best option (usually bi-cubic). Use TIFF or 100% Jpeg when possible. The image will definitely look different from a print. It is the same principle as on a computer screen. It will have significantly more contrast with vibrant colors and bright highlights. If you use though a business-class projector, mostly targeting text and graphics, the color gamut will be limited and most details in the highlights and shadows will be gone. Check to see if there is a "movie" mode and use that, or use something to calibrate it.Avoid, "text", "graphics", "presentation" or "bright" modes since they tend to increase contrast by reducing color details. I routinely project images on a105" diagonal screen and they look great.

03-07-2012, 11:02 AM	#3
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	I was shocked at how good 2MP images from my collection looked when projected even on a fairly basic projector. But these were images with limited color info to worry about losing (mostly high ISO concert images with strong tungsten/halogen lighting).

03-07-2012, 12:23 PM	#4
bjake Veteran Member Join Date: Mar 2011 Location: Eastern Kentucky Posts: 416 Original Poster	Excuse for being so uninformed on projected images but it is a completely new subject for me.I have no idea as to what type of projector will be used,have seen it used,seems to change colors toward the green cast on some images but good on others.Am I being advised to resize to 2mp for the projected images? Thanks, Jake

03-07-2012, 12:53 PM	#5
demp10 Veteran Member Join Date: Jun 2011 Location: Atlanta Photos: Albums Posts: 602	Originally posted by bjake Excuse for being so uninformed on projected images but it is a completely new subject for me.I have no idea as to what type of projector will be used,have seen it used,seems to change colors toward the green cast on some images but good on others.Am I being advised to resize to 2mp for the projected images? Thanks, Jake Jake, it is always a good idea to resize the images for the targeted output. You do not know how a projector will scale down your images. It may use an interpolation algorithm or simply skip pixels. You have much better control on your computer. Besides, the projector will display the images faster since it does not have to spent time resizing. Just find out what the native resolution of the projector is and use that. If it is a home theater-type projector then most likely it will be 1280x720 or 1920x1080. If it is a business-type projector it may have one of the standard computer resolutions like 1024x768 or 800x600. On the color cast, it is important to either calibrate the projector if possible, or use one of the display setting that produces natural images with smooth gray/color gradations. If the projector has an sRGB mode use that to start with. If you can set color temperature use 6,500 K or set custom Red-Green-Blue to get a neutral image. A simple test to judge color casts is to display a medium gray image which it should look gray. Any color hue will indicate that the white balance on the projector is not setup correctly. You may be able to hook up the projector on a computer or DVD player and use a calibration DVD to set it right. In any event you will be impressed with the overall quality of the displayed image.

03-07-2012, 11:32 PM	#6
bjake Veteran Member Join Date: Mar 2011 Location: Eastern Kentucky Posts: 416 Original Poster	Guess I must get in touch with the fellow who is showing the images and find out what size he needs. Thanks all, Jake

03-08-2012, 08:30 PM	#8
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	Historical notes: I read a pro's account from 1/2 century ago, when he was asked if 35mm frames could be enlarged to 20x30. He replied "Sure -- 20x30 FEET, not inches." Recall that in pre-digital days, commercial cine was shot on frames about 24x18mm, what we'd call 35mm half-frame, very close to the size of our APS-C sensors. And those frames were regularly projected onto screens 30x45 feet or larger. The trick here is that images will look good in very great enlargement, so long as they aren't inspected too closely. Those cine frames were normally viewed from some distance away -- folks in the front row at a theater probably weren't pixel-peeping the action, eh? I can take a 912x1216 shot from my 1.1mpx Sony DSC-P20 P&S (circa 2001) and enlarge it to 9x12 feet -- and as long as it's viewed from 15+ feet away, it looks fine. So, keep the audience at a distance, and all will be well. No necking in the front rows, now...