Difference in monitor vs projector displays

[Guest Yachtsman1]

Hi Dave

The reason for the suggestion that we stick to the maximum suggested slide size of 500kb was to keep within the PTE manual guidelines. If I take a picture in raw, re-size it to 1024x768 then convert to a JPEG, which is the size I construct my shows and use the maximum quality 10 in Elements 5 it ends up way above the 500kb max.

The original suggestion was to create a test piece, to fit within those guidelines. So that anyone contemplating new equipment could use it as benchmark to test the equipment. If the guidelines are exceeded then the test piece is void. Additional test pieces to suit the newer resolutions could be constructed, and itemised as being specific for that resolution.

Regards Eric

PS

This particular picture is from one of my shows built using 5.6 beta??. It was shot in raw and the original was 15.5mb, it was sized at 1024x768, converted to JPEG then saved at "Quality Good" in elements 5 which equates to level eight i think and ended up at 840kb+ 50% above the max recommended, so in my mind if I animated it and found a fault, I have only myself to blame. Hope this explains the way I'm thinking.

[JRR]

Jim,

My suggestion was as a starting point for a set of "instructions" or "rules" which would allow anyone to construct his or her own show to test both laptop and projector.

So taking your comments into consideration you would recommend that (presumably for a 1024x768 projector) one of the tests be a 15 second pan using a 3:1 image at full height?

If you translate that into a formula for a 1920x1080 projector your suggestion becomes 3240x1080 (I said 3000+ x 1080) so I wasn't far out and I accept your suggestion of 15 seconds.

The same figure for a 1400x1050 projector would be 15 seconds pan - 3000+ x 1050.

I don't think that the width of the image would matter but I can see that the speed of the pan might.

Would you agree on that as a starting point?

Would you also agree on the importance of using a quality 12 image in order to provide the maximum "drain on resources" and eliminate another variable?

DaveG

Dave:

While a test file would be great, I think we need to apply the brakes here a little.

It would be nice to hear from Igor on this issue. He has worked many magic "tricks" with PTE to look after all our varying requests. It is been suggested in other posts in this thread, that maybe it is a "simple" matter of slowing the frame/refresh rate on certain animations or another option for outputting an .exe file for projection.

We also don't know yet why some computers seem to be able to handle the projection issue with no problems. Is it that they can reduce the refresh rate (with or without the operator knowing) and/or is it a matter of some internal chip set or internal coding?

It may well be the refresh/frame rate is the only factor, but we don't absolutely know (but it is a good bet) but we need to eliminate other causes/solutions first.

The test file that Ed has made available was prepared after many weeks of trail and error in identifying the problem. We found that the image size (pixel or kb) make very little if any difference in the projection issues. Not sure why that file would not be a good starting place. BUT what about other animations and effects...do they have problems with projection alone ?

Ed and I tested with pans and zooms as that is where we are in our shows, we are not into the many other animations that can be used to create a more "with it" show. (Ed and I (well me anyway) are "old school" photographers and AV producers.

I happened to view JP Dollangère's Mon Maitre show the other day. It is a great show of the practical use of PTE (although some of the aspects might be more of a demo than practical use to my mind - but I still think it is something for me to aspire to). But it strains my computer (at PTE's recommended specs)to say the least. The projector has issues with it, but not the jitteriness that we have with simple pans and zooms so I am inclined to think that had I computer spec'ed to handle that show, the projection might (?) be OK.

So there maybe is a need to re-quantify the specs needed for PTE first. (and should that be on a level based on what aspects of the software you are going to use )

[Ed Overstreet]

Like Jim, I'd prefer to hold off until we hear something from Igor on this issue, before spending any significant additional time on this issue. Jim and I have spent a lot of time on this, other projects (photographic and otherwise) that are at least as important to us are suffering as a result, and at the moment I'm feeling that there are too many variables, in addition to the many that we've already ruled out, for me to cope with on this. We've heard only about the projector aspects and limits on this issue so far; I'd like to hear from the software developers as to what, if anything, could be done in the software.

I'd much rather try to see if there is some way of getting some of our existing hardware to run these things properly, maybe with some upgraded components or different connections if that's really going to fix the problem, before running out to spend more money on newer equipment which, as we all know both from computers and from digital cameras, will become obsolete almost before we get the darn thing home and out of the packaging. Maybe that's my creeping old age talking, or maybe it's wisdom bitterly acquired after having been through this too often with too many photographic and computer toys over the past ten years or so. I should have told my investment broker to invest my money in electronics and photographic equipment instead of those catastrophes he recommended that I buy into.

I agree some test shows, both "basic" and maybe separate ones that "push the envelope a bit," would be good, but first I'd like to hear whether anything can be done in the software.

And yes, like Jim, I'm "old school" AV, having cut my teeth about twenty years ago on two slide projectors, a dissolve unit and a four-track tape deck. What a nightmare compared to the joys of working with PTE, especially when you want to tweak something a little bit. But it taught both of us to build AV shows on image blends and transitions, since Fades were all we had available at the time. Even now, I rarely want or feel the need to do more than one or two pans or zooms in an 8-minute show, I think they are more impressive if done selectively, rarely, and when they make a difference, rather than running them almost every transition for no obvious reason, as we've seen some producers at our club events do over the years. PTE does great basic fades, and if that's all it could do, I could live with it (since that's what we lived with for about 10 years before digital was an option). But it sure would be nice to be able to trust a projector to pan through a panorama stitch without tearing it apart or making it look like the camera is being held by someone who needs to consult a physician ...

[davegee]

I'm not sure that anyone has properly read what I suggested.

I'll leave it to you guys.

DaveG

[fh1805]

This post is in reply to Brian(Conflow)'s post #84 on page 5.

I’ve now followed the steps that Brian (Conflow) asked me to do (to document the refresh rate of my graphics cards). Out of interest, I did it on all my systems and not just those tha I use with the projector. On the Fujitsu laptop I did it with the projector attached and not attached; and when the projector was attached, I did it with the laptop monitor active and not active. And the results?...

- The HP Desktop computer operates at 75Hz (I don't connect the projector to this PC)

- The Acer laptop operates at 60Hz

- The Fujitsu laptop operates at 60 Hz

- The Dell projector reports the incoming signal as Analogue VGA 1024x768 60HZ in color mode sRGB in all situations.

The Fujitsu gave the same value (60Hz) no matter what the state of the connection to the projector. The projector gave the same (detection) result no matter which laptop I used and no matter what the state of the monitor on the laptop.

So, it would seem that the Dell projector thinks that all the incoming signals have the same attributes. It would seem that both laptops think they are delivering the same frame rate; and the Fujitsu thinks it is delivering the same signal irrespective of whether the projector is attached and irrespective of whether the monitor is active or not.

And yet the projected image is different when the Fujitsu's monitor is not active. So something is happening that is different. WHAT IS IT? I feel that the answer to that question is the key to unlocking this puzzle.

regards,

Peter

[coopernatural]

Hi Peter,

I think there are several weak links in the chain, and that's the problem.

Only as strong as the weakest one.

I don't have the answers to the problem, but some things to consider.

The refresh rate for your laptop is the norm usually about 60hz.I do not think that this is the same for projectors especially at larger resolutions.

You may not have the option to change this frequency within your laptop.

The laptop may well be struggling before it gets to hand on the 'Video Baton' to the projector.

To take the strain of the laptop,you can reduce the colour output from 32 to 16 in Display properties.

Also you may need to adjust the slider on the video acceleration.

shutdown unnecessary background processes,and tweak the system for performance. You can be lazy and get one of the bits of tweaking software,but you can do a better job if you can read up and do it for yourself.

It's always a good idea to improve your security settings while you are at it.It's a good tweak in itself.

Make sure to download the latest drivers.Is there enough ram in machine?

This is not intended as a cure for anything other than helping a laptop that is under pressure,but it may help overall.

Some of the better graphics cards in desktop PCs will allow you to enable vsync lock.

Video gamers don't like this enabled as it reduces the frame rates of their games,but it does reduce tearing.

If the tweaking software is not installed for the graphics card it is usually available as a download.

How this impacts in the projector performance,I don't know,but in the absence of some input from a tech guy,it might be worth looking at.There are other settings within the software,refresh lock,triple buffering etc,but I don't know enough about that or how it will effect things.

It might pay to pose a question on the Video Help forum as there are some knowledgeable peeps there.

The owners of other projectors here could also pose a question to there suppliers,or the manufacturers for help.

The choice of projector is going to make a difference.We just got a new LCD projector as it is supposed to be better with regards to projecting static images as opposed to the DLP type more suited to home cinema.

Where's Igor when you need him?

Regards,

Davy

[Ken Cox]

Davy

see

http://www.picturestoexe.com/forums/index....ost&p=61671

practice "RAT'S"

read all threads

ken

[JRR]

While it is somewhat embarrassing, we seem to have solved the jittery projection associated with my projector, the Panasonic PT-LB10U. This was one of the two projectors Ed and I have been using in our tests.

There is a function called FRAME RATE that we were unaware of (as we hadn't read/understood the manual clearly enough)

With FRAME RATE turned "on" the jitteriness smooths right out on our test files of pans and zooms.

Obviously we haven't tested every animation that has been run in PTE.

Nor have we resolved the issue with the Canon Sx50 projector nor Peter's Dell projector along with other people's projectors that we have heard from during this post.

If interested, the reference to the FRAME RATE is on page 42 of the PT-LB10U manual which can be found here

The hint to try the Frame Rate came from a member of our Camera Club who has been lurking around this forum as well our updates to the situation on our Club website

[JRR]

Just a quick correction

the feature is called FRAME LOCK, not FRAME RATE

[cjdnzl]

Just a quick correction

the feature is called FRAME LOCK, not FRAME RATE

Ha!! That will be the answer. Here is a quote from a Canon projector specification for their Xeed 6 model [http://www.letsgodigital.org/en/news/articles/story_6504.html]

"Frame Lock ensures correct synchronisation between computer and projector when presenting animated slide shows, eliminating interference and horizontal banding".

Perusal of Google searching on 'projector "frame lock" ' shows that quite a number of projectors have Frame Lock in their specification - but some do not mention it, including the SX-50 and SX-60 The SX-50 write-up says that machine is designed for high quality graphic and photographic images, and not home theatre, which I take to mean moving images. Perhaps that is why there appears to be no Frame Lock mentioned in the specs - but of course it may be available on the projector menu. We need Ed to verify that.

Colin

[JRR]

Perusal of Google searching on 'projector "frame lock" ' shows that quite a number of projectors have Frame Lock in their specification - but some do not mention it, including the SX-50 and SX-60 The SX-50 write-up says that machine is designed for high quality graphic and photographic images, and not home theatre, which I take to mean moving images. Perhaps that is why there appears to be no Frame Lock mentioned in the specs - but of course it may be available on the projector menu. We need Ed to verify that.

Colin

We have a few leads on similar terminology with the Canon Projector.

It would have been more helpful to have more support from Canon (and Panasonic) on this.

Unfortunately access to the Canon projector (our camera club projector) is not as simple as accessing my Panasonic which is in my "AV room" semi-permanently set up, plus Ed and I are "tested out" at this point but we will be following up soon.

In the meantime we are hoping this might be a lead that others with the same problem can follow up on and report any success.

[Ken Cox]

JIM/ED

I hope you tell the canon panasonic people that you are highly dissatified with their support - and fwd the things you have found on your own !

ken

[Guest Yachtsman1]

I have found Canon support to be adequate, but Panasonic abysmal. I reported a problem with my TV just before Christmas, no response. I then sent it back to Amazon an bought the newer model Pansonic which has an anomoly with the remote control, (the TV is connected to the DVD recorder with a Veira link) and you are supposed to be able to use one remote, however when the TV is switched on from cold, the range of the remote is reduce to about 1 metre & takes around 15 minutes to acheive 5 metres. I asked Panasonic if this was normal, after 3 weeks no reply. It could be they are in trouble as they announced 2000 jobs to be shed.

Yachtsman1

[JEB]

Yachtsman1,

I have had a look at my SX50 User Manual and came across a number of user settable options that may have a bearing on your issue.

I couldn't see anything about Frame Lock but on pgs 56/7 they talk about Input Signal Type. Apart from NTSC, PAL, SECAM, NTSC4.43, PAL-M & PAL-N you can also select 1080i, 1035i, 720p, 575p, 480p, 575i & 480i. I have no idea what the last group are but perhaps they have some relevance as they suggest that "when images from AV equipment is not projected correctly (irregular colour or no image), you can select an input signal manually".

Pg 53 offers - Adjusting the Tracking when the projected image flickers due to a tracking error.

Hope this is of use.

Regards

John

[Conflow]

John

You wrote.." you can also select 1080i, 1035i, 720p, 575p, 480p, 575i & 480i. I have no idea what the last group are"...

These are the ATSC Video Standards....(Advanved Television Standards Committee) It means that your Projector

has the ability of selecting and switching between these Standards ~but~ your PC may not have the VGA-Drivers

to compliment those selections should you run a Slide-Show with PZR effects.

The 'suffix letter p or i' indicates as follows p=4:3 Screen Ratio and i=16:9 Screen Ratio (Including HDTV)

You need only be concerned yourself with these Stanfdards:- 720p ~ 1080i Standards unless you have a monster

Plasma Screen then 108i and 4801i would apply.

The 'Link' below will describe all:-

http://en.wikipedia.org/wiki/ATSC_Standards

Brian.Conflow.

[Picsel]

John

You wrote.." you can also select 1080i, 1035i, 720p, 575p, 480p, 575i & 480i. I have no idea what the last group are"...

The 'suffix letter p or i' indicates as follows p=4:3 Screen Ratio and i=16:9 Screen Ratio (Including HDTV)

Brian.Conflow.

Hello Brian I might have missed something as this thread is now very long. I hope I have followed up the discussion but nothing is clear for me and It would be great If someone could make a summary for a better and common understanding.

However, I just want to come back on your previous post

In my knowledge the suffix letter "i" stands for interleave (compatibility with old CRT TV screen using 1/2 frames)

and "p" stands for progressive (compatibility with new LCD screen and digital TV programs)

and so whatever the format 4/3 or 16/9 as both exist with CRT or LCD

Am I right or wrong?

Best regards

Daniel.

PS : I have also read on this thread several posts concerning frame rate at 60Hz that is true for american standards but european ones are based on 50Hz (as far as I know), that is due to power electricity distribution frequency.

[Ken Cox]

"PS : I have also read on this thread several posts concerning frame rate at 60Hz that is true for american standards but european ones are based on 50Hz (as far as I know), that is due to power electricity distribution frequency. "

I believe they are talking about monitor refresh rate -- i run my monitor refresh rate at 75hz

ken

[Ed Overstreet]

JIM/ED

I hope you tell the canon panasonic people that you are highly dissatified with their support - and fwd the things you have found on your own !

ken

Hi Ken.

I don't trust myself to send Canon an email yet, in my present mood the language I'd use wouldn't be very "civil." Maybe in a week or so, when we've cooled off a bit, one of us will figure out a way of communicating our dissatisfaction in words that someone might actually read through and think about -- if they're capable of thinking about customer feedback. "Sorry it's a characteristic of the projector, we think, can't help you" really isn't impressive performance by Canon in my book. I'll leave it to Jim to deal with Panasonic (I dealt with Canon, Jim with Panasonic since it's his projector). The switch that fixed the problem is, after all, in the user manual (albeit well-buried and somewhat cryptically referenced), one would have thought they might have suggested it to us ...

From other comments above I suspect that with these two companies, as with others I've dealt with, a lot depends on which particular tech support person you happen to get. Some of them are very helpful and cut right to the chase, others are hopeless. It shouldn't be that way, but it seems to be. It happens so often that, rightly or wrongly, I've given up sendng feedback or asking to speak to a supervisor (after being on hold for 20 minutes) because I have more interesting things I'd like to do with my life. However in this case I think I'll make an exception

But yes dealing with tech support in these two cases has been REALLY frustrating. I've already told our colleague at the club that Canon and Panasonic should fire their tech support and hire him, he's better at it. But I suspect his day job pays better ...

As Jim mentioned, our colleague has suggested a couple of other things to try on the Canon, but Jim and I can't get back to the Canon again until mid-March so it will have to wait 'til them. As a backup Jim has agreed that if necessary for our club showcase in April we can use his Panasonic for projection, now we know how to get IT to work, though that isn't ideal because in the large hall and large audience we have, the Canon's higher resolution and brightness are preferable (when it works, which it actually does for most other things in PTE).

We will of course keep everyone posted on what we find out with the Canon, but it won't be for a month and a bit, sorry. Bookmark this thread and stay tuned. And we'll keep monitoring this thread in case others here come up with a fix before we do (if there is a fix for that projector; I find it hard to believe there isn't, but it won't be the first time that expensive hardware has disappointed me if that's how it ends).

Or maybe there's a software work-around that may occur to Igor and his team, but I appreciate he and they have a lot of other things on their plate and there are no doubt limits to what they can do with this problem. But we live in hope.

As a final aside, like Ken I run my monitor at 75 Hz, at 60 Hz I find the flickering (especially in the white parts of the screen, in all software) is too annoying and tiring for my eyes.

[Conflow]

"PS : I have also read on this thread several posts concerning frame rate at 60Hz that is true for american standards but european ones are based on 50Hz (as far as I know), that is due to power electricity distribution frequency. "

I believe they are talking about monitor refresh rate -- i run my monitor refresh rate at 75hz

ken

Ken & Picsel,

We have to be careful what we are talking about here, as follows:-

1)

Computers: All modern PCs and Laptops have a Frame-Refresh rate of 60.Fps (mistakenly) called 60.Hz Refresh-rate.

The National 50/60.Hz Grids are no longer used for synchro-purposes as modern PC.Clocks are ultra accurate and are

auto-refreshed every 5/7 days over the Internet (XP and Vista).

2)

Televisions:- In the USA you have CRT.TV Sets and LCD.TV and Plasma.TV. The TV.Signal is sent out at (nearly) at 60.Fps

and is intergrated into 30.primary frames which are 'interlaced' with 30.secondary frames giving a composite Picture of nearly

30.Fps. (Interlacing is only needed with CRT.Screens whereas. Progressive Scan is used for Digital.Screens).

3)

In Europe we have the same senario only that we Transmit at 50.Fps and a similar 'intergration' takes place ~ only this time

we have 25.fps/25.fps interlaced for CRT.TV Sets and Progressive Scan for Digital Screens.

4)

Interlacing is part of the internal mechanism of a CRT.TV and nothing to do with the TV.Signal nor the National Grid.

5)

In the "old-old days" of 405 Line.TV and old 525 Line.TV we used the National Grids 50/60.Hz as a synchronising signal for TV's.

Thats well gone ~ nearly 35 years ago.

Brian.Conflow.

[Conflow]

Peter and Ed,Jim,Ken,Colin and Others,

Peter,

Your Post #105 above you wrote..."And yet the projected image is different when the Fujitsu's monitor is not active. So something

is happening that is different. WHAT IS IT? I feel that the answer to that question is the key to unlocking this puzzle"..............

I had replied that I know nothing about your Fijitsu Computer except that its 'data-buss' would be slower than modern PCs and I

also suspect that its VGA Output-System is driven by special Fijitsu-Drivers incorporating a set of 'Sync-Pulses' for CRT.Monitors

and LCD Displays. In reality most modern Desktops dont have any "bespoke-drivers" for external Monitors nor Projectors excepting

those generic-drivers supplied by Microsoft to cater for a broad range of 'Plug & Play Devices' such as external Monitors/Projectors.

Stand back for a second and consider the Fijitsu Computer ~ of course you are correct about its own Monitor -V- External Device.

It uses one set of drivers to run its own LCD Monitor and MUST switch over to another set to run an external Monitor/Projector.

Thats how they all work ~ just that in your case Fijitsu ~ being the 4th largest Chip-Manufacturers know how to make things work.

Having said that, some of the more expensive Graphic-Cards have switchable 'Sync-Lock' you Guys call it 'Frame-Lock' ~ thats simply

a market ploy because most people would'nt know a 'sync-pulse' if it bit them ~ then why should they ?

Ed,Jim,Ken,Colin and others

In previous Posts I had wrote..." there is more to Video-Projection and Monitors than meets the eye" ~ you asked for it and here it is !!

and particularily note about Frame-Rates and Synchronising-Pulses not to mention 'corrupted' JPeg-markers when using PZR effect.

Link:- A short Course on Video-Signal Formats (Mitt Institute Technology)

http://web.mit.edu/6.111/www/s2004/NEWKIT/vga.shtml

Link:- From one of our suppliers Maxim Semiconductor Corp ~ Video Basics.

http://www.maxim-ic.com/appnotes.cfm/an_pk/734

These will explain in detail what's going on with that Video-Signal going to your Projector and it is clearly shown that if your Show

does not fall within the Specified-Standards requirements of YOUR PARTICULAR PROJECTOR....then need I say more !

Enjoy,

Brian.Conflow.

[FlightDeck]

Hello all,

I'm just joining into the discussion, however I've already been involved "behind the scenes"---I've been helping JRR and Ed Overstreet, and helped uncover the Frame Lock feature on JRR's Panasonic projector which helped a lot in his case.

We did another round of testing this week with Panasonic and Canon projectors, with no real improvement. (I believe Ed may be posting on the detailed results separately.) Following that I kept working some theories between myself and another engineer, and came up with three vectors on which to act. Cutting straight to the conclusion, they are:

1) (long-term) Hound projector manufacturers for "frame protection" capabilities and/or higher refresh rates.

2) (immediate) Test shows on computers with DVI output from the video card and DVI input to the projector.

3) (short/medium term) Get WnSoft to test a software mod that limits frame rate to a user-specified maximum.

I'll leave it to the user world at large to press for #1. I'll be contacting WnSoft with specific recommendations related to #3, which hopefully they'll entertain.

For #2, I request that users could post results of the following test. If you have a PC video card with digital output (DVI) and a projector with digital input (also DVI), please indicate whether using this connection reduces or solves the problems with panning. When posting your results, please specify the refresh rate setting on your PC's video card. If possible, perform the test at 2 different refresh rates: one at the lowest possible setting (probably 60 Hz on most systems), and one at the highest useable setting, if there is one.

~~

For those with the time/inclination to read long theories, posted below is the background logic that leads to the above 3 actions. In the absence of detailed information on the inner working of the projectors, I make can make no guarantees it is 100% correct, however I believe all the concepts are on the right track. Pieces of this are not new and have been discussed here and there throughout this thread and in other places---I am only trying to tie it all together into a theory and courses of action which make sense to me within my engineering knowledge.

(The explanation below is at a high level with limited detail, for a broader audience. Underneath, however, I have a considerable amount of very technical details in the realms of analog and digital signal processing, digital sampling theory, video processing, etc.)

Here's the theory... As I had proposed some time ago, I believe the issues are a frame-rate "incapability" between the video card in the computer and the projector. All of the symptoms I've heard of and witnessed point in this direction. All the projector specs I've reviewed indicate many have a frame rate of about 60 per second (60 Hz). Our TV signals (in North America) are 30 fps (interlaced), and movies (film) are 24 fps. This means the projector operates plenty fast enough to properly project these sources.

Computer video cards, however, usually run no slower than 60 Hz, and often well higher. This means a video card can send new frames to the projector faster than it can project them. If the projector has no "frame protection" capability to ensure it completely projects one frame before starting the next one, then it will interrupt itself in mid-frame and start projecting the next one. If the input in question contains motion, such as a slideshow pan, then you will see a rip/waterfall/wipe going down the screen. While only noticeable during such motion, the reality is that it's always present, even on still images---you just can't see it because both the old and new frames are the same.

My suspicion is that the Frame Lock feature on JRR's Panasonic is just such a "frame protection" capability. Problem is, it seems not all projectors have it. This is actually understandable given the main markets for projectors would be corporate presentations and tv/film. The former are generally static images and basic animations, where the users probably don't encounter the issue (or don't often enough to care). And the latter, as already mentioned, are at low enough frame rates to be within the projector's 60 Hz capabilities.

So what's the fix, in the global sense? In theory the options are:

1) change projector design/capabilities

2) change PC video output design/capabilities

3) change slideshow software design/capabilities

1) If projectors are produced with a suitable "frame protection" feature, then all the problems should go away. This will obviously not come as a quick fix to those of us at the coal face. All we can do here is try-before-buy on new projectors, and hope they have the capability.

And obviously, digital projectors that could get their butts well above 60 Hz would be a huge improvement for us all!

2) If we could force the PC video output down to, say 30 Hz, it should be within the projector's capabilities and *may* reduce the problems. But depending on whether 1) has been implemented, it may not *eliminate* the problems. This option is not likely to happen, as the general utility of a computer screens running at only 30 Hz is very poor.

Alternatively, there is a possibility that some projectors will work perfectly fine if they are given digital input instead of analog. RGB, S-video, Component, Composite cables are all analog. The LCD projector is a digital device, and therefore must perform the analog-to-digital conversion itself. If the input were at a low frame rate, there would probably be time for the projector to receive each frame of input, perform A/D conversion, and then project it in time for it's 60 Hz refresh cycle. However if we send it 60 Hz analog from the computer, I suspect it's not getting enough time to process the input frame entirely before needing to project it. This might partly explain the jittery stuff at the top of the screen (frames draw top down).

A *digital* input, however, might have better results. When the PC has a video card with a DVI output connected to a projector with a DVI input, then a digital signal is sent to the projector. No A/D conversion is needed by the projector. Since digital data arriving off the cable is processed very differently than analog, with a more precise/condensed clock cycle, it's possible the projector will have fewer/no problems dealing with it, even when the input is near 60 Hz. This can be tested by anyone with the appropriate PC and projector with DVI output/input. Obviously it can't help projectors lacking a DVI input.

3) The software change idea works on the premise that just because the video card can spin out frames at 60 Hz and higher, we don't necessarily *need* to. If 24 and 30 fps are perfectly acceptable for film/TV, why not for us? Well, there are differences between video and slidehows. Our eyes can accept the drawbacks of low video framerates as there is so much continual motion that we can't detect artifacts as readily---assuming the videographer did a good job. It is very easy to poorly compose a video scene and have it look very juddery, so they use time-honoured techniques to minimize such artifacts, by forcing them into obscure backgrounds while keeping the area of focus relatively artifact-free. Recent hi-def home-theatre systems with 60-Hz progressive scanning have unravelled all this, as they try to display films at higher resolutions and frame rates (60 fps) than they were intended for, and things start looking very juddery. They are dealing with it by either dumbing the system back down to 30 fps, or by artificially generating new frames in between the existing ones (interpolating) to help smooth things out (with a resultant smudging of detail that can make the HD look like regular TV again).

An idea I have is to force PTE to output frames at a lower rate, say 24 or 30 fps. So even if the video card is pushing too fast for the projector, any collisions between frames shouldn't be (as) noticeable as mose of the frames are the same.

I tried to test this concept by creating a show that simulates pans, without actually panning. I put the same slide in over and over again, each time shifted slightly. When you play it, it looks like it's panning, a la old-style animation, but it's nothing more than a rapid series of still images. I set the slide timing to 24 fps (initially), or 40 ms.

The problem? Well, just as explained above for video, it can look juddery, and certainly very much did on my CRT. So I slowed the pan speed down, which helped some, but not enough. So I increased the frame rates back up, to 50 fps or so. Better, but still noticeable judder between frames. And by the way all these adjustments are very tedious to make---at 25 fps a 14-second pan requires 171 slides, each with it's own position setting! So in the end I couldn't make anything nearly as smooth as the built-in pan function in PTE. That doesn't surprise me, but I couldn't even get anything I would consider *acceptable*. Welcome to the world of trying to do smooth animation at low video frame rates.

Anyhow, it's possible, and my hope, that my simulation isn't a good indicator. Because PTE has a lot of things to do, maybe trying to flash through slides at 40 ms intervals is just not realistic. However if WnSoft actually modifies the software to permit limiting the output frame rate to a specific value, it might look more acceptable than my simulation showed. The only way we will know is if WnSoft tries it. They would have to make an alpha-test build with the option to manually set the maximum frame rate the software sends to the video driver. Users could then experiment with the setting to set the lowest fps that minimizes jitters/wipes, while remaining high enough to minimize video judder between frames. (Douglas Adams says the answer will be "42". )

Conclusion:

1) (long-term) Hound projector manufacturers for "frame protection" capabilities and/or higher refresh rates.

2) (immediate) Test shows on computers with DVI output from the video card and DVI input to the projector.

3) (short/medium term) Get WnSoft to test a software mod that limits frame rate to a user-specified maximum.

Thanks and regards,

KDJ

[Ed Overstreet]

Further to Kyle’s post, and to add some context to it: Kyle, Jim and I returned to our club’s projection equipment a couple of days ago, to test the suggestions from Canon Canada tech support and from Kyle. One suggestion was to try the Frame Lock setting on the Panasonic projector; the Canon SX-50 lacks a Frame Lock setting (though some other Canon projectors have one), but there were several suggestions of other projector menu settings to try, that might make a difference.

In a nutshell, none of the Canon SX50 switch settings suggested by Kyle or by Canon solve the "tearing" problem we've identified and have been working on since late December. We are unable to find any configuration of computer or projector settings that can fix the problem on the SX50 to our satisfaction. For the record, the switch settings we varied on the SX50 (which had no visible effect on the problem) were Auto PC, Tracking, and Cinema Mode. It had also been suggested that we try the Progressive Processing setting, but on careful investigation (it wasn’t easy, the SX50 manual isn’t very clear on this point) we found that setting only works when the projector is connected via an S-Video cable. Jim and I had already established that S-Video mode cleared the "tearing" problem but at a cost to image quality that we consider unacceptable.

We verified that the Frame Lock switch on Jim's Panasonic projector fixes the problem when running our test show on his projector through his laptop. That switch ameliorates but does not completely solve the problem when running the Panasonic projector on the club computer, however. The only completely satisfactory projection we have seen of our test show has been on the Panasonic projector, with the Frame Lock set to On, using Jim’s laptop.

Speaking personally, I am very discouraged and frustrated by the unreliability of P&Z performance across combinations of what I think are reasonably-configured and reasonably-specified computers and projectors. I don’t think it’s realistic to wait for the projector manufacturers to pay attention to this problem, as users like us are too small and unimportant (to them) a share of their market. The p&z feature is not very attractive to me if it means I or my club have to go to ridiculous lengths experimenting with different combinations of computer and projector specs to come up with a combination that might actually allow us to pan smoothly on projection through a panorama image at a reasonable pace.

I would really like to hear from the PTE developers regarding Kyle’s analysis and about whether it is feasible to do something in the PTE software to get around this problem.

[FlightDeck]

For #2, I request that users could post results of the following test. If you have a PC video card with digital output (DVI) and a projector with digital input (also DVI), please indicate whether using this connection reduces or solves the problems with panning. When posting your results, please specify the refresh rate setting on your PC's video card. If possible, perform the test at 2 different refresh rates: one at the lowest possible setting (probably 60 Hz on most systems), and one at the highest useable setting, if there is one.

Just a follow-up for the DVI testing, JRR has mentioned that a show is already available for everyone to test, so that we have some consistency. It is available here:

http://www.mediafire.com/?ymwmyurgvik

Within the Zip file, please test with one of the following shows:

• projection test problems 1400x1050 version
  
• projection test problems 1024x768 version
  

The first large pan of the mountain scene should readily indicate if there are any problems.

Thanks,

KDJ

[FlightDeck]

Just a follow-up for the DVI testing, JRR has mentioned that a show is already available for everyone to test, so that we have some consistency. It is available here:

http://www.mediafire.com/?ymwmyurgvik

Within the Zip file, please test with one of the following shows:

• projection test problems 1400x1050 version
  
• projection test problems 1024x768 version
  

The first large pan of the mountain scene should readily indicate if there are any problems.

Thanks,

KDJ

Anyone got results yet for the DVI connection tests?

KDJ

[Conflow]

Hi Guys,

On this subject, I have contributed many Posts some time ago. I am rather surprised why nobody has

given some cognizance to the simple technical content of those Posts for the reason that the contents

will answer many 'puzzle's' as to what's going on with the Projectors you are 'Testing' and comparing.

The 'Screenshot'' below will show why such variations are experienced:-

And if further proof of this is needed please read the 'Article' in Projector Review,viz.

Link:-

http://www.projectorreviews.com/advice/Hom...terpolation.php

I hope this is of some help to you Guys,

Brian.Conflow.