How do I decide between the Canon 55-250mm or 70-300mm + 50mm?
I just bought a Canon Rebel T2i (EOS550D/Kissx4) with 18-55mm kit-lens and I have an additional $300 USD to spend on a lens. I had decided to buy a Canon EF-S 75-300mm f/4-5.6 (without IS) and a Canon EF 50mm f/1.8 and these are just $150 and $110 respectively. However, my friend just got a new camera with an 18-135mm lens so he's selling his current Canon EFs 55-250mm IS for $250.
If I choose Canon EF-S 70-300mm f4-5.6 & 50mm I can get 2 lenses for the same price. If I choose the Canon EF-S 55-250mm IS, I will just get only one.
Advice on which one to choose, please?
You mention it as 75-300 and 70-300. From the price I am assuming you really mean the older 75-300 (of which there are a few models). The newer 70-300 is a good mid range lens for about $500. Just for confusion there is also a 70-300 DO and a really new 70-300L for way more money.
If your purpose is for the outdoors then go with your first option of 2 lenses. Personally I have used both lenses and I feel the quality is more or less the same. Again it depends on your style of shooting, but the 50mm f1.8 is a low light lens which you could use in case of bad light.
The IS in the 55-250mm is nothing great and since you have the ISO advantage its worth taking the risk of the 70-300mm and you would have more range too. Don't worry about the lost 55-75 range. Trust me, it does not matter as you always have your feet to compensate for that. Just walk into your subject or away and you have more or less the same result.
My suggestion would be pick up the first option since you'll have the 50mm. Once you use that lens there is no turning back, especially for its bokeh and sharpness at that price.
In my experience, the lack of IS on the 75-300 makes it unsuitable for many situations that the 55-250mm works well within. It's also a lens that rotates when focused which makes use of a polarizer filter annoying. It can be a very effective lens if used properly but let's not downplay the high value of IS on a long telephoto lens. I acquired my 75-300 quite cheaply from a person who bought it instead of the 55-250 due to the lower price point and then found that they couldn't take any decent photos with it. I own and frequently use both lenses; they both have their strengths.