Re: iMac i5 HD display

You have read something incorrect. The mini-DisplayPort to HDMI adapter gives full 1080p.

Sure - http://www.griffintechnology.com/products/video-display-converter
As you see, it supports up to 1920x1200, which is higher than the 1080p resolution of 1920x1080.

/Edit - http://www.amazon.com/DisplayPort-Female-Adapter-Macbook-Laptop/dp/B002HU629E

And also, if you have sound problems:
http://discussions.apple.com/thread.jspa?threadID=2475332&tstart=0

Wait - so are you wanting to input display to the i5, not output from it to an HDMI source? That wasn't clear at all, but it explains the difference in price.

Output is easy - conversion from DisplayPort to HDMI is simple and cheap, because the graphics card switches to using DVI/HDMI signalling as required.

But inbound - the i5/i7 27" iMacs only take input inwards from DisplayPort devices.

Anything that isn't DisplayPort (like a PS3) needs to be converted to full DisplayPort capability first. That's why an inbound converter like the Kanex is so expensive.

And to add to that - it's possible for a true DisplayPort device to drive the 27" iMac display at 2560x1600 pixels. The capabilities of a converter depends entirely on the makers of the converter. If the Kanex says it'll only do 720p, then that's that.

No problem - it's often difficult to talk tech when you don't know the right phrases.

The outbound usage is simple - to add second screen. Another monitor, a projector, or (with that $4 adapter!) a 72" TV.

Sorry I couldn't suggest a better-than-720p input adapter, I've not looked for that sort of kit at all. And if a 720p is going to be $150... ouch!

http://store.apple.com/us/product/H0360LL/A?mco=MTY3ODQ5OTY might work.

It seems Bartbrn looked into the issue and found the following explanation for the limitation: http://discussions.apple.com/thread.jspa?messageID=11858407#11858407

Apparently (according to Kanex) the iMac accepts only two input resolutions, 1280x720 and 2560x1440.

This Belkin device I mentioned in my previous post: http://store.apple.com/us/product/H0360LL/A?mco=MTY3ODQ5OTY
makes no mention of a 720p limitation; and says:
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+Scales resolution to fit the entire iMac or Cinema Display (supports 480i, 1080i, 480p, 720p, 1080p resolutions)+
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Maybe this means it works around the limitation by upscaling the HDMI input to 2560x1440? It's just a guess though, you'd have to check reviews or other sources to make sure.

billbir wrote:
This is probably what confused me as the Kanex only allows 720p and I thought that this limitation was imposed by Apple.

According to the site Kanex ( http://kanexlive.com/products/item-id-3662.html), you are able to get output 1080p from the Kanex XD -- it's the iMac which is limiting it.

"Full screen HD playback of Blu-Ray DVD, Playstation 3, Xbox Elite, Direct TV, Dish Network or other components with HDMI output set at 720p. This is due to limitation of the iMac 27" as a display which accepts only 1280x720(720p) or 2560x960 resolution base on the display EDID. If when the iMac 27" accepts a 1920x1080(1080p) resolution the Kanex XD will be able to output at 1080p."

So, I had a quick look at the Belkin website: AV360™ Mini DisplayPort Converter for 27"iMac
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+Accepts full 1080p signal, provides 720p to iMac+
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So it's slightly more convenient than the Kanex in that you don't have to set your device's output to 720p, but the signal reaching the iMac will still be 720p.

If there's going to be scaling, it might as well be upscaling to 1440p rather than downscaling to 720p, IMO; especially in a product that does cost a fair amount. It makes you wonder whether 1080p-limited hardware entered production before the limitation was discovered, and downscaling was added as an afterthought.