Hi Lente,
I haven't seen any member's replies from this area, so I hope this helps. I live south of Portland, OR and within 1 hour's drive of Mt. Hood and have for most of my life. I am into hiking and non-technical climbing in the Cascades and their foothills, logging over 400 miles/year and 100,000' + elevation gain. I take photos ALL the time, but am not up to the skill levels of a LOT of the UH people, I'm sure. I do it for enjoyment and get a lot of compliments on my pics. That's what it's about for me.
Back to the point, one suggestion I have is - - - if you are able to route your trip from Eugene area to Sun River - I would definitely recommend taking Hwy. 126 out of Springfield, then staying on Hwy 242 to Sisters. This is known as McKenzie Pass. You will go through awesomely beautiful wilderness areas, and volcanic lava fields that are like a moonscape with Cascade peak views. Hwy. 242 puts you right into Sisters, which is a convenient connection to head to Sun River.
Also, just south of Cannon beach, Arcadia beach or Hug point are really cool, especially when you catch them non-weekend. A little bit farther south at Oswald West SP, a hike out Cape Falcon has great possibilities. Don't hesitate to follow deer trails to remote, beautiful areas that most tourists will never see!
Contrary to non-resident belief, the month of September has VERY good odds of being nice. The local long-range forecasts are really good right now. I know it's all a roll of the dice around here, but it looks good for the next month, from what I see.
Most likely Crater lake will be passable, too. It's at 6,000' so that definitely makes if iffy, but things look good for the near future.
Don't waste your time on bear bells, either.
I hope you have a fantastic trip! This is an incredible part of our country.