Mini Display Port to Projector issue

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Level 2

326 points

Mini Display Port to Projector issue

I've just bought a Mac Mini to use as our media server. It is connected to our Panasonic projector via the Mini DisplayPort to VGA adaptor, then to a 30-foot VGA cable that connects to the projector.

The image appears no problem, just as it did when we used to use a MacBookPro for this same purpose. However, same as the MBP, the displayed image is smaller than that of the DVD player which is plugged into the projector via HDMI. Whereas the DVD image is 6 foot wide, the computer image is only about 4 feet wide. I can of course adjust the projector to enlarge the computer image to fill 6 feet. But then when I play a DVD, I'll have to adjust it back. I'd like the Mac to put out the same size image as the DVD.

If I change my projector's aspect ratio to 16:9 when the Mac is plugged in, then it fills the 6' screen. However, the aspect ratio is off. I'd like the Mac image to be 6' wide with a 4:3 aspect ratio.

The Mac Mini display is set at 1024x768, 60hz. Any ideas?

MacMini, Mac OS X (10.6.2)

Posted on Dec 29, 2009 2:16 PM

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Answer 1

kguy

Level 2

420 points

Dec 29, 2009 4:35 PM in response to Paul Seymour1

Hi-

The problem is the fact that you are connecting your mini to the projector via VGA, as opposed to HDMI or DVI. VGA is an analog connection, whereas HDMI/DVI is digital.

When you connect anything to your mini via HDMI/DVI, it is able to autodetect the display it is connected to. With VGA, it isnt, and you are forced to configure using System Preferences, Displays.

Solutions- can you connect your mini to your projector via HDMI? You will need the mini-dvi to DVI cable included in your mac mini box, in addition to a DVI-HDMI cable (cheap- maybe $14). If you do, the Mac mini will be able to autodetect the projector, and you are good to go.

OR (second best)

Connect via VGA, and download a free tool like SwitchResX to configure the Mini to output at the desired resolution.

OR (quick and dirty fix which is actually rather lousy)

Connect via VGA, and under display settings, try a setting like 800x500. This will make adjusting between the DVD player and Mini unnecessary, but it is like viewing the world through blinders.

Message was edited by: kguy

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Answer 2

BSteely

Level 5

7,643 points

Dec 29, 2009 9:25 PM in response to Paul Seymour1

Is there an Overscan option (check box) showing up in Displays preferences under a tab labeled Options? If so, does toggling it have the desire affect?

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Answer 3

kguy

Level 2

420 points

Dec 30, 2009 3:28 AM in response to BSteely

Hi- as for overscan, that is only an option when he connects digitally via DVI or HDMI.

I just verified this on my own TV set- when connected via VGA, the displays setting does not even show overscan as an option, but when switching to HDMI, it pops up.

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Answer 4

Paul Seymour1 Author

Level 2

326 points

Dec 30, 2009 11:10 AM in response to Paul Seymour1

Hi all,

Thanks for the informed replies. To my credit, I tried to avoid this issue before I bought the MacMini, via this thread:
http://discussions.apple.com/thread.jspa?threadID=2264644&tstart=0

From that, I came away with the sense that VGA=DVI. Now that doesn't seem to be the case.

Right now I've got 1 HDMI cable and 1 VGA cable going to the projector. These cables are long and are running through the walls, so I'd like to avoid having to buy and run any more cables if possible. The HDMI cable is currently connected to the DVD player.

I tried downloading SwitchResX and changing the resolution manually. However, no matter what resolution I set, the image remains roughly 4' wide. Within that size, there are more or less pixels depending on what I set the resolution as. However, the overall image never gets any wider.

Is there any solution where I can continue connecting to the projector via the VGA cable, and can get a 6' wide image? Or am I stuck with installing another HDMI?

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Answer 5

BSteely

Level 5

7,643 points

Dec 30, 2009 3:59 PM in response to Paul Seymour1

Paul, I've gone back and reread your first post and I have come away with a different understanding from the first time I read it. Now that I read it, I observe the following:

\- You are sending 16:9 video from a DVD player and it is displaying at approximately a 6 foot width.

\- You are sending 4:3 aspect video from the Mac and expect it to also be 6 feet wide, but it's only 4 feet wide.

I believe those two desired outcomes are at odds with one another. Likely the full width of the imaging engine is in use when displaying at 16:9 through the projector optics. Therefore, it only stands to reason that when you send 4:3 aspect video from that same imaging engine, it necessarily has to be cut down in width. As you note, you can adjust the projector's optical zoom to enlarge the 4:3 image to 6 feet, but that is by virtue of the lense system. The image size coming off the projector's engine is not changing.

Another way of looking at this to to think of a conventional, direct view TV, like an LCD HDTV. If you put 16:9 content on the screen, it fills the screen to full width. If you put 4:3 content on the TV, there would be black pillars to either side of the image and the image cannot be full width. The situation with a projector is really no different than this.

I guess what I am trying to say is there is no way to do what you want without fiddling with the projector's image enlargement function (optical zoom). Is there some reason you don't want to send 16:9 video from the Mac? That should solve the problem.

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Answer 6

Paul Seymour1 Author

Level 2

326 points

Dec 30, 2009 9:21 PM in response to BSteely

You make a great point about running 16:9 video from the Mac Mini. I'd be happy to do that. However, by using SwitchResX and any other resolution settings, I'm never offered any 16:9 aspect ratios to choose from, and I'm never allowed to simply type in any ol aspect ratio. All the aspect ratios are 4:3.

I can switch the projector to 16:9, and then it stretches the image to fit. But I can't seem to get it to scale at the correct proportion.

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Answer 7

kguy

Level 2

420 points

Dec 31, 2009 5:35 AM in response to Paul Seymour1

As a workaround...

Does your Panasonic projector have a DVI input, or component video input?

If it has component video input, how about switching the DVD to component, and using HDMI with your mini?

Alternatively, if you do have a dvi input in the projector, just connect the mini to it, and all of these problems will disappear instantly.

To assist, can you let us know the model of your Panasonic projector? We can verify the best ways to connect your gear.

Message was edited by: kguy

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Answer 8

Paul Seymour1 Author

Level 2

326 points

Dec 31, 2009 9:37 AM in response to kguy

My projector is a Panasonic PT-AX200U. It does indeed have component video connections. However, I'm really trying to avoid running any more cables from the computer to the projector, and am hoping to get HD through the VGA cable.

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Answer 9

BSteely

Level 5

7,643 points

Dec 31, 2009 10:57 AM in response to Paul Seymour1

Well, the good news is your projector is compatible with wide formats coming from a computer (page 45 of the user manual). The bad news is apparently no such formats are part of the projector's EDID backing the VGA port.

You should be able to save the situation using a program like SwitchResX. SRX can be used to build custom timings that the manufacturer failed to include in the plug-and-display driver (EDID). I recommend you build a 1280 x 720 format timing since that is the native size of the projector's engine element. If you need help with SRX, write back.

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Answer 10

carana

Level 1

50 points

Dec 31, 2009 11:18 AM in response to Paul Seymour1

Have you considered removing the DVD player from the equation altogether, and just using the DVD drive in the Mini itself?

You can get digital audio output from the Mini using the correct cable (the little headphone jack has a TOSlink emitter inside it).

If you take the HDMI cable out of the DVD player, and dedicate it to the Mini, it sounds like your troubles would be over.

G. Discenza

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Answer 11

Paul Seymour1 Author

Level 2

326 points

Jan 25, 2010 9:06 PM in response to carana

Hi Carana,

I took your advice. I got a mini-DVI to HDMI adaptor, hooked that up to the HDMI cable that goes to the projector. The result: no image at all. However, if I plug that HDMI cable into our DVD player, everything works fine.

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