Viewing photos on Projector

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I've been asked to show a few photos at our local birding club. Its quite an informal affair, most of the time we just sit about chatting.

They meet at a pub but only been meeting there about 18months. In the room there's a projector attached to the roof, no one at the club's ever used it but it looks fairly modern, HDMI lead to attach to lappy so seems straight forward

All the images I've sorted are around 3800 x 2500 pixels (roughly), @ 300ppi.

After a Google (Ok, maybe I should have done that first ;)) I've just read that the optimum size for showing on a projector is 1024 x 768 @ 72ppi

So my question is -

Will 3800 x 2500 pixels @300ppi be ok? Is more less when viewing on a projector ? Would I just be better to resize them all to 1024 x 768 @ 72ppi?

Also owt else that might be helpful?

As said, its very informal but I've never used or seen any of me shots through a projector before, thanks
 
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Why not make a visit in advance and try it out.
You could always used IrfanView to batch convert them to any size in a minute or two.
I take little longer to make files in a variety of sizes to try out.
If you do not have Irfanview it only takes a moment to download and is free. I use it all the time to convert for the web.
 
If I wanted to show my images at their best, I would borrow a decent projector and ensure the laptop/projector combination was calibrated. This is what we have to do at camera clubs to ensure high quality for competitions and visiting speakers. I very much doubt that the projector is very recent given that it is 1024 by 768 a very old standard. The club used to have one of those but retired it almost ten years ago. You can also assume that the projector will be sRGB so you must ensure that your images are also. For the club, we would normally save a copy at the relevant projector resolution and sRGB but in practice the competition software we use does this automatically.

What software were you thinking of using for showing your images. Since W10, the Microsoft options are not ideal so we use Irfanview for showing visitors images; it is free. I also agree with the rehearsal. If you turn up and find various problems, you may not have time to resolve but they could be resolved at a rehearsal.

Dave
 
It may not help but I have projected many images (via a Laptop) at various events and the actual size has never been considered?
The projectors I have used have had limited zoom abilities so I have on occasion had to physically change the distance 'projector to screen' to give the ideal full screen image.
I have also used a couple of modern fixed setups....as in your case.... and source image size was irrelevant.

PS. Laptop is Windows 10 Pictures and all Jpeg.
 
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There is no benefit to having images w/ a higher resolution than the projector can reproduce, but there is also no negative to it either... it's very much like viewing your images on different screens w/ different resolutions/display sizes.

You can also assume that the projector will be sRGB so you must ensure that your images are also.
The projector is an RGB device, no idea how wide it's gamut is though (sRGB/NTSC/aRGB/etc). But it's only reproducing the monitor output of the computer which is also an RGB device... it doesn't matter if the image is a raw file; what's important is that the program being used to display the image is displaying it correctly.
It would also be nice if you could set up a display profile for the projector (calibrate), but I imagine that's unlikely. There should be the ability to adjust some projector settings so that it more closely matches the monitor display visually; but since no-one has used it before I imagine you are on your own in figuring out how to access/adjust them.
 
Thanks for the replies, much appreciated

I'm going to use Microsoft Power Point to display the shots , I didn't know but it was already on me laptop, I've added them to a presentation programme that fades one to another

So am I right in saying as far as file size goes, there is no set answer, one projector can be different to another and also distance from projector to screen can make a difference too?

It may not help but I have projected many images (via a Laptop) at various events and the actual size has never been considered?
The projectors I have used have had limited zoom abilities so I have on occasion had to physically change the distance 'projector to screen' to give the ideal full screen image.
I have also used a couple of modern fixed setups....as in your case.... and source image size was irrelevant.

PS. Laptop is Windows 10 Pictures and all Jpeg.

This sounds promising though. (y)

Think I'll take the advice above and go try it first with different sized images, its only a bit of fun but you never know where it might lead............:LOL:

Thanks again, Phil
 
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So am I right in saying as far as file size goes, there is no set answer, one projector can be different to another and also distance from projector to screen can make a difference too?
The resolution of the projector has nothing to do with the image size/ppi... It's more akin to printing your image in draft mode (i.e. 1024), printing at standard quality (1920/HD), or printing at max quality (3840/4k).
Projector distance does affect the spread/size, but all that I have used have had a zoom lens.
 
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I have also used Power Point in a few instances with no problems.
In my case it was always to show images where absolute quality was not the point....can I say that on a Photographic Forum?:rolleyes:;)
Good luck:)
 
All the images I've sorted are around 3800 x 2500 pixels (roughly), @ 300ppi.

I've just read that the optimum size for showing on a projector is 1024 x 768 @ 72ppi
OK, a couple of problems here.

Firstly, your ppi figures are meaningless. If an image is 3800 x 2500 pixels then it is 3800 x 2500 pixels, full stop. You could choose to print it at 300 ppi, in which case it will come out at roughly 13" x 8", or you could choose to print it at 100 ppi, in which case it will come out at 38" x 25", or at any other resolution you like. But the image is still 3800 x 2500 pixels and the ppi figures are not intrinsic to the image.

I hope it's obvious that the ppi you achieve when you project the images, if you care about it, is simply a function of how big the display screen is. Project 1024 pixels onto a screen that's 8 feet (96") wide and you've 1024 / 96 which is got a bit more than 10 ppi, and so on.

A useful rule of thumb is that, if you want to avoid pixellation being visible in your images, you need to arrange it so that ppi x viewing distance in feet = 600 or more. So if you really are projecting a 1024 pixel image onto an 8 foot screen, you will see the pixellation unless you are 60 feet away. So I guess you probably do care about ppi, at least if the screen is big and the room isn't.

Secondly, 1024 x 768 is not necessarily optimal for the projector. You need to check what resolution the projector can output. It might be 1024 x 768; it might be higher; it might be lower. You can get 4k projectors now, at a price. The one we use at our camera club can use 1920 x 1200. The one I got to use at a local scout hall recently was 800 x 600. You need to check the model of the projector, and check its specifications.

Thirdly, you need to think about aspect ratios. If the projector is 1024 x 768, that's not the same aspect ratio as your images. So how do you want to present them? Crop to fill the screen, or letterbox them?

Finally, if you are using Powerpoint to show the images, make sure the "page" size is set appropriately (to match the aspect ratio of the projector), and it's a good idea to re-size the images to fit your output resolution before inserting them into the Powerpoint presentation. That way (a) they will load faster, and (b) you can decide on what sharpening to apply.
 
OK, a couple of problems here.

Firstly, your ppi figures are meaningless. If an image is 3800 x 2500 pixels then it is 3800 x 2500 pixels, full stop. You could choose to print it at 300 ppi, in which case it will come out at roughly 13" x 8", or you could choose to print it at 100 ppi, in which case it will come out at 38" x 25", or at any other resolution you like. But the image is still 3800 x 2500 pixels and the ppi figures are not intrinsic to the image.

I hope it's obvious that the ppi you achieve when you project the images, if you care about it, is simply a function of how big the display screen is. Project 1024 pixels onto a screen that's 8 feet (96") wide and you've 1024 / 96 which is got a bit more than 10 ppi, and so on.

A useful rule of thumb is that, if you want to avoid pixellation being visible in your images, you need to arrange it so that ppi x viewing distance in feet = 600 or more. So if you really are projecting a 1024 pixel image onto an 8 foot screen, you will see the pixellation unless you are 60 feet away. So I guess you probably do care about ppi, at least if the screen is big and the room isn't.

Secondly, 1024 x 768 is not necessarily optimal for the projector. You need to check what resolution the projector can output. It might be 1024 x 768; it might be higher; it might be lower. You can get 4k projectors now, at a price. The one we use at our camera club can use 1920 x 1200. The one I got to use at a local scout hall recently was 800 x 600. You need to check the model of the projector, and check its specifications.

Thirdly, you need to think about aspect ratios. If the projector is 1024 x 768, that's not the same aspect ratio as your images. So how do you want to present them? Crop to fill the screen, or letterbox them?

Finally, if you are using Powerpoint to show the images, make sure the "page" size is set appropriately (to match the aspect ratio of the projector), and it's a good idea to re-size the images to fit your output resolution before inserting them into the Powerpoint presentation. That way (a) they will load faster, and (b) you can decide on what sharpening to apply.

Thanks Stuart.........plenty to think about there!

The room is quite small and the projector is fairly close to the screen, about 10ft maybe.

Tbf, I'd not taken any notice of it until showing a few photos was suggested. I, quite naively, just thought I'd pop along with me lappy, plug it and that'd be it :rolleyes:

One of me mates that goes is a lot more computor literate than me and we're going to go beforehand and do a test run, so to speak, hopefully he'll have more idea than me when it come to set up

The way you've explained above though is starting to make sense

Cheers, Phil
 
I've been asked to show a few photos at our local birding club. Its quite an informal affair, most of the time we just sit about chatting.

They meet at a pub but only been meeting there about 18months. In the room there's a projector attached to the roof, no one at the club's ever used it but it looks fairly modern, HDMI lead to attach to lappy so seems straight forward

All the images I've sorted are around 3800 x 2500 pixels (roughly), @ 300ppi.

After a Google (Ok, maybe I should have done that first ;)) I've just read that the optimum size for showing on a projector is 1024 x 768 @ 72ppi

So my question is -

Will 3800 x 2500 pixels @300ppi be ok? Is more less when viewing on a projector ? Would I just be better to resize them all to 1024 x 768 @ 72ppi?

Also owt else that might be helpful?

As said, its very informal but I've never used or seen any of me shots through a projector before, thanks

I suspect that Google answer is several years out of date.

The optimum size for projecting will depend on the resolution the projector has. (The ppi part of it is TOTALLY irrelevant, for computer displays).
The projector our club uses projects something like 1200x800, (it's certainly above SVGA but less than the maximum resolution of the laptop screen). Our's is too old to have HDMI.

When projecting images higher than the projectors native resolution our viewing software (FastStone) rescales automatically, but we are left with the option of zooming in. Rescaling is fast enough that it can be done on the fly for JPEGs of this sort of size, even on an XP based laptop. RAW files can be a lot slower!
 
As said, its very informal...

I wouldn't over think this. Assuming the audience are there to look at the pictures and not nit-pick your photographic skills put high res, full size jpegs into PowerPoint and have at it.
 
Ideally you need to know the output resolution of your laptop and the native resolution of the projector, match these and you'll get the best picture quality achievable. If the output of the laptop is too high for the projector, the projector will compress the image and you will lose detail.
As you increase the size of the image on the screen the more it will 'pixelate' but keeping the resolution from the laptop as high as possible without causing the projector to compress the image will help enormously. As a guide an 8' wide image should be suitable for upto 100 guests.
 
I wouldn't over think this. Assuming the audience are there to look at the pictures and not nit-pick your photographic skills put high res, full size jpegs into PowerPoint and have at it.

This^

I’ve done nearly 40 talks to camera clubs over the past 5 years and I just bang the pictures into a pictures to exe presentation and let that sort things out. I have no idea what the resolutions and suchlike are.

Sure, you always want to present your pictures in the best possible way, but other than variations between the quality of projectors (which is arguably more of an issue when you’re presenting high contrast black and white like I do), I’ve never had any issues. Before my first talk, my main contents were having enough pictures to fill the time and practising what I was going to say.

Good luck, and enjoy!
 
I would find out what the the projector is capable of outputting. I know at our club we use 1600x1200 to show on a screen.
 
My only experience of a projector was at a camera club talk I gave last month. I was asked to present the illustrations and photos on a USB stick, and the club would handle everything. After that first prelimary trial a week before the talk (I'd sent a couple of images to them) I was asked to severely downsize them as their equipment was talking 4 minutes to render each image.

I have no idea what the laptop, projector or software was that they were using. But based on that, size matters (with some equipment).
 
Thanks again for the advice and thoughts (y)

I wouldn't over think this. Assuming the audience are there to look at the pictures and not nit-pick your photographic skills put high res, full size jpegs into PowerPoint and have at it.

Hopefully Ed, this is what I was originally thinking but its all too easy to wonder if I've got in too deep :runaway::LOL:

Before my first talk, my main contents were having enough pictures to fill the time and practising what I was going to say.

I've got around 3 dozen photos to show, not sure if that's enough or not, I could add more but don't want it to drag on.

And I've already put them straight, it won't be a talk as such, I'll show the photos, try answer any photography related questions and we'll chat about the birds as a group........hopefully! :)
 
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My only experience of a projector was at a camera club talk I gave last month. I was asked to present the illustrations and photos on a USB stick, and the club would handle everything. After that first prelimary trial a week before the talk (I'd sent a couple of images to them) I was asked to severely downsize them as their equipment was talking 4 minutes to render each image.

Stephen for our own club members we normally ask them to resize for the projector 1920 by 1200 JPEG and sRGB. The competition S/W we use can cope with Tiff's as well and can resize and convert aRGB to sRGB. However, I have noticed that there is a pause of almost half a second on the odd occasions someone has not re-sized. We do have fairly high spec Laptops but the largest images we would see would be from a FF DSLR. I suspect that your images may be much larger. Visiting speakers do mainly seem to know they need to re-size etc and a few bring their own equipment. Calibration can be a problem for visitors so we do try to persuade them to use our equipment or it is OK if they bring their own (both Laptop and projector). All in all the quality of our projected images is significantly better than when we started digital projection in 2005. For those who properly calibrate at home, they can expected the image projected at the club to be very close to what they see on their computer screen.

For print competitions, we have to project the image as well though the judge only looks at the print. With a large hall and up to 80 members attending only a handful will be able to see the print when judged. We do try to display prints later as many realise that the quality of the print is still much higher than the projected version.

Dave
 
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