Installing PS3 games

[DealsR4theDevil]

Would it matter at all if during the game installation i turn off my TV (which is connected via HDMI, so i guess the PS3 knows the TV is off) and turn it back on after it finishes installing?

The reason I ask is because up until now all my PS3 games looked amazing (and the old ones still do). Uncharted, Resistance, Ratchet and Clank, The Godfather, Heavenly Sword and Ninja Gaiden all look phenomenal. Some may be less detailed then others but the image is always smooth and sharp.

Recently I have purchased Gran Turismo 5 and GTA 4. Both games had to be installed onto my system and both games look waaaaay to soft. The Gran Turismo HD Concept Demo looked better to me then the actual game. Everywhere I go online people are raving about the graphics of these 2 games. Which leads me to believe that I may be doing something wrong.

I know that keeping my TV on during install is a long shot but I would appreciate any suggestions.

PS: Yes my TV is calibrated and yes all my blu-rays and old PS3 games still look phenomenal.