Unable to control brightness in target display mode

Ah, I now did try a keyboard connected to the iMac when the MacBookPro is connected, I can indeed adjust the brightness. Still, I see the following issues:

1) I need to keep an extra keyboard around (I use the keyboard with the MacBook when connected).

2) It doesn't remember my brightness (it goes to full brightness every time)

3) I can't controll it from my MacBookPro as I used to be able to

So, while it works, it is far from perfect. Any suggestions on fixing the issues from above's list?

Hello everyone!!

I used to have the same problem, Ive tried to connect a macbook pro with an imac 27, the both on snow leopard. Impossible to adjust the brigthness on the imac as monitor!!

After calling the assistance service, we conclude that apple hasnt yet fix this problem...

BUT.....HOPEFULLY

There is a solution !!! You can download the software named : " SHADES " , and It works well, you'll will able to change the brightness of your macbook and your imac .

Cheers

Hello There !

Thanks for fabien14's great suggestion.

SHADE does a nice clean job. After a simple download and installation, now I can easily control brigntness on BOTH my macbook pro mid 2011 and imac 27 late 2009 INDEPENDENTY !

No need to turn my beloved Snow Leopard imac 27 into the unthinkable Lion !

Thanks fablen14 ! Thanks for the discussion ! Cheers !

I just hooked up my macAir (2011 model) using mini displayport to my 2010 iMac. Screen in target display using CMD +F2, when I want to leave I use the wireless keyboard attached to my iMac hitting CMD-FNC+F2 to return to my imac.

I can control the birghtness on the iMac (which by standard) is brighter than the sun, by lowering the birghtness on the wireless keyboard. So the brightness on both the iMac as my macAir can be setup indenpendently of each other.

I work with Mac OSX 10.7.3

Hope this helps

@patrick thanks for the input. You may be able to help me. I think you i have your same configuration (macAir 2011 and imac2010, wireless keyboard attached to imac). My question to you is on the keyboards, are you using more than the one wireless keyboard you mention?

Thanks in advance for any input

@patrick Also, you are saying "i use the wireless keyboard attached to my imac hitting CMD-FCN+F2 to return to my imac"

Please clarify:

1) If the wireless keyboard is attached to the imac, what keyboard you use for the macbook air when in Target Display mode

2) Apple official instruction is "command+f2" to enter and exit, per this http://support.apple.com/kb/HT3924

Are you using "CMD-FNC+F2" or "CMD+F2" ?

Thanks again for any help

@macmacjose:

Answers

1) I use the keyboard that is on the macAir, so no external keyboard here. Only for the iMac I use a wireless external keyboard from apple.

2) see step plan:

Step plan:

1) boot both iMac and macAir

2) login to both imac and macair

3) connect the Mini Displayport cable between the two

4) Now hit CMD-F2 on the wireless keyboard of the iMac

< now the iMac should show be in target display mode and you can control the arrangement etc.

5) use the CMD-F1 or CMD-F2 keys on the wireless keyboard to control the brightness of the iMac

to exist Target Display mode on the iMac, the CMD-F2 on the wireless keyboard did not work. I had to use CMD-FN-F2 in order to exit the Target Display Mode on the iMac.

After this action the mac Air and iMac are two separate computers again.

Hope this helps.

Regards

Patrick

@patrick thank you so much for the answer and prompt reply, right in time for me.

Regards

Jose

I'll try that, but for now, I'm wearing sunglasses! Works pretty well if they're not polarized...

I know this discussion is ancient, but for posterity, and anyone still running Snow Leopard, I have found a temporary SOLUTION to make it work again!

This applies to Mac OS 10.6.8 so anyone still running that version (like moi) and having this problem can clear the problem for a little while.

1. Open the Disk Utility
2. Select your Startup disk (i.e. "Macintosh HD")
3. Make sure you are on the First Aid tab
4. Click the "Repair Disk Permissions" button
5. Wait for the operation to complete
6. Restart your iMac with the other device connected to it (MBP, PC, whatever)
7. Login as normal.
8. Hit Cmd + F2 to activate Target Display Mode and then test the brightness control with F1 and F2 once the image stabilizes.

You should be able to control the brightness. At least, in my testing it seems fairly consistent. You can switch back and forth with Cmd+F2 as many times as you like and you should still have control of the brightness.

There is but one caveat: restarting your iMac will reset whatever is causing the problem and you will have to Repair Disk Permissions again and reboot. So, just don't restart your iMac. One other minor annoyance is you have to readjust the brightness every time you use Target Display Mode, but that seems a small price to pay for getting control back!

Hope that helps somebody out there.

🙂