I agree with Chris. I also have both. I would add that the 100-400 is much easier to carry all day and handhold. If the rumors are correct a new version of the 100-400 is soon to be announced. The current ones might then go down in price.
Bill

I have the Canon 100-400 and the Tamron 150 - 600mm. I also had the Sigma 150-500. My go to lens is the Canon 100-400 because it is as sharp as the Tamron and better for BIF because.it is handholdable and I can carry it all day. If you are unhappy with your Canon 100-400, you will probably not be happy with the Tamron. You also will not be happy with the Sigma. I found the Canon 100-400 to be sharper and to have better focusing and contrast than the Sigma. I sold my Sigma for that reason. Consider the Canon 400 f5.6 prime. I have that lens too and it is sharper than the 100 - 400, sharoer than the Tamron 150-600 and much sharper thanb the Sigma 150-500 that I had. The 400 f5.6 is great for BIF even handheld and even though it does not have IS, as long as you use a high enough shutter speed. I like the Tamron 159-600 for its reach and find it to be about as sharp as the Canon 100-400. I use it on a gimbal.
Bill

How much do you want for the 100 mm 2.8 macro?
Bill

Excellent photos especially the water lilly.

Disagreement doesn't = disrespect. I agree that the first 2 pictures are blurry.

Maybe the softness is attrbutable to the lens. Which 70-300 mm lens is he using? I had the nonL 70-300 and I found it to be soft at 300mm. I now have the 70-300L lens and it is a major difference.
Bill

That's very helpful. You did it without a flash?

They are beautiful photos. My favorite is no. 1. What method did you use to freeze the action? The wings are crystal clear and tack sharp.
Bill

Incredible. I have been trying to get a good photo of the pleated woodpecker for years. They are so elusive. What camera and lens did you use?
Bill

Steve,
Those are great photos. What are your settings? I am still trying to learn to get good photos from my sx50. I have the same DSLRs as you. I'm happy with them but I still struggle with the sx50. I am inspired to keep trying by people like you and Linda.
Bill

I have the 300 f4 and the 70-300 L. I use the Canon 1.4 extender on the 300 prime and get very good results at 420mm. I like both lenses and get sharp images with both. My only complaint about the TC on the 300 prime is some CA in high contrast situations. But I am able to correct the CA in Lightroom.
Bill

How do we ship them back? Do we need a form?
Bill

Wahawk,
Thank you for that info. I never explored the digital zoom on the sx50.
Bill

Where is the internal teleconverter on the sx50? How do you activate it?
Bill
quote=Wahawk]To get more distance between lens & camera you can also activate the internal tele-converter at either 1.5x or 2x which enlarges the image and keeps the focus a little farther from front of lens.[/quote]

Ronjay
Fantastic photos.
What camera did you use?
Bill