Chefneil - you should not be downloading and posting another person's hummingbird (customer Wei @ B&H).

I don't know what else you're looking for? If you're looking for confirmation that it's the lens rather than your technique, you will not get that affirmation from me. Your two images are underexposed, have a soft focus, and have been poorly processed. Posting them as a pseudo apples to apples comparison to a different camera and the work of a far superior photographer; it only reflects poorly on you and has nothing to do with the equipment ...

The only difference that is obvious is the possible excellent results of this lens in the hands of another photographer ...

I have been doing a little bird photog lately. The Audubon Society has a chapter in my area and they go for some walks on the weekends. So I have been joining them, see my posts on my blog https://thewonderinglenzofolc.blogspot.com. Well, I have been feeling a little inadequate with my measly little Canon 75-300. Some of those guys have these big long things that nearly touch the bird. LOL! So I have been trolling the web and my local Camera shop trying to find an implant to reduce my inadequacy.

They had a Sigma 100-400F5-6.3 DG. Well, lets say "HAD." Now I do!

I took it out for a spin and was a little underwhelmed by it. When I looked at the images I had taken with it on my iPad nothing seemed to be sharp and the colors where kind of flat. I took a deep breath, reminding myself that I had 30 days to return this thing and get my money back. I went out this morning to the local Power plant cooling lake, Lake Julian, and shot a few more images. This time I used my tripod to mitgate any hend held blur. You wanna know the 75-300 seemed to be sharper throughout.

This went against everything I thought would be true. My world is shaken. I reread the reviews I looked at. I looked at the images posted from the camera. THEY were sharp. Then I relooked at my images. Consistantly the images at the lower range were sharper. So I scratched my head and tried to figure out if maybe it was user error. The truth is, a couple of images were not so bad at the longer range.

I ticked through the sentient facts:
1. I know my camera and how to take good pictures with it.
2. I had a new lens, but it had no tripod mount. I had to mount my camera body, maybe causing some wobble.
3. I was using a light tripod.
4. Low light and high ISO to compensate

Perhaps....Naw, that could not be the case. It had to be the lens. I could not be the issue.

Well, after a heavy lunch, of lamb shanks and Baklava, thanks to the local Greek Festival, I was not going any where. I needed to sit down and digest! Not being a football fan (the the Pats rule!), setup shop in the backyard to try again. I used my studio tripod for stability and waited.

After a while, some LBJs came by and picked at the bird feeder. Here are the best of what I got over the weekend.

Now, you can comment on my picture composition all you want. But, I really want to know what you think of the IQ, Color Aborrition, Noise, Bokeh, and so forth.

Thanks olc

I have been doing a little bird photog lately. The Audubon Society has a chapter in my area and they go for some walks on the weekends. So I have been joining them, see my posts on my blog https://thewonderinglenzofolc.blogspot.com. Well, I have been feeling a little inadequate with my measly little Canon 75-300. Some of those guys have these big long things that nearly touch the bird. LOL! So I have been trolling the web and my local Camera shop trying to find an implant to reduce my inadequacy.

They had a Sigma 100-400F5-6.3 DG. Well, lets say "HAD." Now I do!

I took it out for a spin and was a little underwhelmed by it. When I looked at the images I had taken with it on my iPad nothing seemed to be sharp and the colors where kind of flat. I took a deep breath, reminding myself that I had 30 days to return this thing and get my money back. I went out this morning to the local Power plant cooling lake, Lake Julian, and shot a few more images. This time I used my tripod to mitgate any hend held blur. You wanna know the 75-300 seemed to be sharper throughout.

This went against everything I thought would be true. My world is shaken. I reread the reviews I looked at. I looked at the images posted from the camera. THEY were sharp. Then I relooked at my images. Consistantly the images at the lower range were sharper. So I scratched my head and tried to figure out if maybe it was user error. The truth is, a couple of images were not so bad at the longer range.

I ticked through the sentient facts:
1. I know my camera and how to take good pictures with it.
2. I had a new lens, but it had no tripod mount. I had to mount my camera body, maybe causing some wobble.
3. I was using a light tripod.
4. Low light and high ISO to compensate

Perhaps....Naw, that could not be the case. It had to be the lens. I could not be the issue.

Well, after a heavy lunch, of lamb shanks and Baklava, thanks to the local Greek Festival, I was not going any where. I needed to sit down and digest! Not being a football fan (the the Pats rule!), setup shop in the backyard to try again. I used my studio tripod for stability and waited.

After a while, some LBJs came by and picked at the bird feeder. Here are the best of what I got over the weekend.

Now, you can comment on my picture composition all you want. But, I really want to know what you think of the IQ, Color Aborrition, Noise, Bokeh, and so forth.

Thanks olc

Chefneil - you should not be downloading and posting another person's hummingbird (customer Wei @ B&H).

I don't know what else you're looking for? If you're looking for confirmation that it's the lens rather than your technique, you will not get that affirmation from me. Your two images are underexposed, have a soft focus, and have been poorly processed. Posting them as a pseudo apples to apples comparison to a different camera and the work of a far superior photographer; it only reflects poorly on you and has nothing to do with the equipment ...

The only difference that is obvious is the possible excellent results of this lens in the hands of another photographer ...

Like most new, expensive toys, this one needed for me to learn a little more than I knew before. I did some shots in the basement "Studio" with a focus sheet and even a fuzzy llama, on a steady tripod. I used my heavier one to get rid of as much lens shake as I could. But I did not jack up the ISO. Most of the time, when I am down there, I shoot at 100 ISO.

And I was not so happy with the results. So, then I reread the replies you guys sent and one important thing kept coming up: I was shooting at too low a shutter speed. But I was in the "studio" with my good tripod, surley that would reduce shutter shake! Not so much. Although the llama is OK, I still did not think I was getting the best out of the lens.

Finally a light bulb went off. Use higher ISO! Yeah, I know that is just plain obvious to get faster shutter actuations.

So, here are some images which I took the other day, and today, at 1600 ISO. They are much better. Now, all I need to do is learn how to find birds which are interesting enough to use this lens with---oh and how to compose a pleasing memory!

Like I said in the OP, you can kibitz on the composition. But what I want to have is honest opinions of IQ and so forth.

Thanks again! olc