Are Tamron and Sigma trustworthy as compared to Canon? I am a beginner, so please help me. I have my kit lens Canon 18-55 mm. However I am looking for a telephoto zoom lens. For this reason a Canon EF-55-250 mm IS II lens was my first choice. But I am confused with Tamron and Sigma. Although I prefer Canon, its expensive for me. I want a pretty sharp zoom lens with which I can have better zoom for birds.
The short answer is yes, they are trustworthy but your question seems to be more orientated towards the 'should you go for the cheaper version' kind of area.
In some cases, people would consider the Tamron/Sigma equivalent to be better, but that's subjective and can take into account many things such as build quality, features, price and of course picture quality. The two brands; like Canon also have a professional range and a good line-up of options from the cheap to expensive.
The best advice is to start by looking into the lenses that are suitable for your needs, then find the one in your price range and compare the model from each three companies, which you can by either trying them or reading trusted reviews (there are plenty out there).
Hope that helps.
bro you have asked for the suggestion about sigmas and tamron's status and lens suggestion for your camera .
Honestly bro they both are very good Brand but for being 3rd party we regret their power and goodness :)
i think One's need of lens depend on
if you like wildlife Photography with macro and since you are beginner and using eos550D
then go for a Macro-Tele-Photo lens would be a nice choice ..
happy clicking :)
I personally use only Canon lenses, for this reason I can't compare Canon with other brands, like the already mentioned. However, Canon produces very good to excellent zoom lenses. One example of a cheap lens is 55-250mm (here are different versions of this lens: http://www.amazon.com/s/ref=nb_sb_ss_i_3_6?url=search-alias%3Daps&field-keywords=55-250mm&sprefix=55-250%2Caps%2C413), which would maybe be a good option for your 550D camera. However, all of them are not compatible on full frame cameras. So, if you consider to upgrade on a full frame one day, this lens will not fit! For this reason, you could consider 70-200 lens f4 USM: http://www.amazon.com/Canon-70-200mm-Telephoto-Zoom-Cameras/dp/B000053HH5/ref=sr_1_1?ie=UTF8&qid=1396359023&sr=8-1&keywords=70-200mm+f4. Although it has not IS - image stabilization!
It depends on how much money you can invest at the moment and what you are chasing. For example, the 55-250mm f4.0-5.6 IS can be wider than the 70-200mm, whereas the latter has USM - ultra sonic motor, which makes the autofocus quicker and more silent.
If you eventually chose some lenses and you are still uncertain, you can check their specifications and compare them at www.lenshero.com.
Hope that helps!
I bought my (older) Canon 55-250 IS refurbished, and I think it's done very well for me. Just a few examples here. I do not have experience with the Tamron or Sigma equivalents, but I consider mine good value for money. I'm using it with the 500D/T1i.