Bigbeartom44

This is for information. I recently bought a Tamron 16-300mm telephoto lens to replace my Nikon 55-300mm lens. Everything that I read indicated that the Tamron 16-300 II was a real winner. The first thing that I did was to compare photos of one with the other. There were many photos taken from a fixed place to the same objects so that I would know exactly where they were taken. They were taken with my Nikon d5300 body at f/8.0 as this was the best setting of both lenses. Also in full sunshine at 1/200 second. First the good news, this lens is much better that the original Tamron. Also it has a 16mm to 54mm that the Nikon doesn't have. But when I compared the pictures one on one I noticed something weird. I used the 300mm setting on both as that was the maximum on both. Side by side the Tamron photo was smaller, and what I mean by that it looked like a 270mm maximum not 300mm. I will attached two photos from the Nikon and Tamrom taken from the exact same place. The distance was about 65 feet away. For some this may be trivial, but I can't afford a larger telephoto and most of my photos are birds at a distance and every millimeter counts. The top photo is from the Nikon 55-300mm and the bottom one is from the Tamron 16-300mm.

BebuLamar

If you try at closer distance you may see more of a difference.

Soul Dr. Loc: Beautiful Shenandoah Valley

This is called lens breathing. Google it and you can find many explanations of it.

blackest Loc: Ireland

well it may actually be a 290mm lens called a 300mm and it may suffer from focus breathing.
http://www.imaging-resource.com/news/2014/12/17/what-is-focus-breathing-and-how-does-it-affect-your-images

rmalarz Loc: Tempe, Arizona

What Tamron probably did was take a few millimeters off the 300mm end and put them on the lower end to get to the 16mm. It's a technique called lens shaving. They hope that you, the buyer don't have another 300mm to test it against.
--Bob

BebuLamar

May be not but one can measure the size of subject on the photo vs real and calculate the focal length.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

http://www.bobatkins.com/photography/technical/focus_breathing_focal_length_changes.html

I am pretty sure when you get a lens that is not "internal focus" meaning that the lens actually changes it's size as you focus, you will not have focus breathing. Many lenses manufactured today are internal focus, which move around elements within the lens to achieve closer focus - with the undesirable effect of shortening focal length to get closer. At infinity, you are less likely to see a difference between your two lenses, and at the shortest focal distance you are going to see the most effect of breathing.

boberic Loc: Quiet Corner, Connecticut. Ex long Islander

When you look at the railing at the bottom right, you will notice that the "larger image" was cropped a touch differently than the smaller one (second picture). That might very well account for the difference.

Bigbeartom44

Thanks for the info on focus breathing. I measured the difference between the Nikon and Tamron and it is 10%. For 300mm that amounts to 30mm or a telephoto of 270mm instead of 300mm. I watched the video and I didn't see any thing like 10% difference. I decided that the cost of the Tamron and cost of the Nikon it wasn't worth it. Right now I can get the Nikon 55-300 for $200 open box and $500 for the Tamron. That it 2.5 times the cost of the Nikon. I think that I will go for the more for a lot less. I appreciate the learning that I am getting on this website. If I didn't already have a 16-50mm lens, I might have gone for the Tamron, it is an excellent lens even being a little short.

Bigbeartom44

More info: I did not crop either photo. These are the photos just out of the Nikon d5300. Both are 6000-4000 pixels. You see more in the Tamron photo because it is in effect a 270mm lens and not a 300mm lens, it takes in more at the same distance. Wide angle vs telephoto. Also the Tamron has a feature that the Nikon doesn't, that being a close up feature. I believe that Tamron chose to add features in a smaller package and had to make a choice about what was important. Like I said, it is an excellent lens, but I think that Tamron should have marketed it as a 16-270mm telephoto.

MT Shooter Loc: Montana

Just so you know, there is no Tamron 16-300mm "II" version lens, there is only the original, unchanged 16-300mm. Although Tamron is releasing an 18-400mm lens this coming Friday. It will not replace the 16-300 but will be sold alongside it.

Winslowe

It's been pointed out several times why that would be false marketing.

JohanneT Loc: South Africa

Can I just put a correction in here, you talk about a "300mm Telephoto". This lens is not a Telephoto, (telephoto lens have a fix focal length) but rather a zoom. Zoom lenses have "focus breathing /zoom breathing" and that differ from one lens to another.

BebuLamar

prime lenses have focus breathing too. Only lenses that focus by simply move the entire lens doesn't have focus breathing.

jerryc41 Loc: Catskill Mts of NY

Poo Free? How much do the other parks charge?