bdk Loc: Sanibel Fl.

Try this , shoot something 500 feet away and see what difference there is.

Rab-Eye Loc: Indiana

This was a fascinating and educational thread.

cactuspic Loc: Dallas, TX

I understand you don' t like Tony Northrup and want to gratuitously trash Ken Rockwell, who I did not mention. One of the interesting parts the Northrup comparison is that he tested two version of the Nikon 70-200 mm zoom. The results showed that version version I had significantly less focus breathing (similar to the Canon) than version II. Thomas Hogan contrasted the two Nikon version of the 70-200 mm lenses and showed the difference in image size of headshots taken at close focus, 2 meters and 3 meters. His comparison headshots show a significant difference in the amount of focus breathing between the two Nikon versions of the lens when set at 200. This is not to say that version I is better than version 2. The main point of my post is that the amount of focus breathing is a function of lens design and that there may be a significant difference in the amount of focus breathing between zoom lenses with the same nominal focal range. Similarly, I read a review in PetaPixel of the newest Nikon version (3rd version) of the 70-200 which shows significantly less focus breathing than its predecessor at close focus distances using a bunch of bananas. Again my point is not that one lens is a better lens than the other; but that it is a factor you should look at if the amount of focus breathing is important to your photography.

https://petapixel.com/2016/11/22/nikon-70-200mm-f2-8e-review-worth-money-youre-pro/
http://www.bythom.com/nikkor-70-200-VR-II-lens.htm

cfbudd Loc: Atlanta, Georgia

This is the simple and correct answer.

Reinaldokool Loc: San Rafael, CA

Actually no. 300mm is 300mm. Period. You are being confused by all this nonsense about crop and full frame. The theory, as the OP showed is that the lenses should have the same angle of view where they intersect the film plane (sensor). So both SHOULD be the same on the same camera.

speters Loc: Grangeville/Idaho

That was exactly my point!! The focal length still give the customer an estimate of the actual focal length (for what it's close to)!!

steve_stoneblossom Loc: Rhode Island, USA

On an unrelated topic, who made that door for you? Looks quite drafty!

jackpi Loc: Southwest Ohio

The only way that could happen is if one of the lenses is for a crop sensor camera and the full frame camera you mounted it on automatically detected that and switched to crop mode.

oldtigger Loc: Roanoke Virginia-USA

That is not correct, its best to read a thread before posting a comment

jeep_daddy Loc: Prescott AZ

Over and over again I've read very technical explanations of why this occurs. As far as I'm concerned, it's all bullshit. This is not the first time I've seen this exact comparison between a 3rd party lens and an OEM lens. The 3rd party lenses are not everything that some people claim them to be. This is why I stick with quality OEM lenses. You should see the comparison between a Canon 100-400 lens at 400mm and a Tamron 150-600 at 600mm. They are almost exactly the same. You'd think that the extra 200mm on the Tamron would be significant. It's not. And the new 100-400 Mark II is tack sharp.

steve_stoneblossom Loc: Rhode Island, USA

Much evidence to the contrary. There are even differences- reported here and elsewhere- between different versions of the exact same OEM lenses, e.g. Nikon 70-200 f2.8 versions.

Robert Bailey Loc: Canada

I have to disagree with you Jeep Daddy. Many "3rd party" lenses are better quality than "name brand" lenses.
Usually, they are also less expensive.
Dxomark gives the Sigma 85 mm f 1.4 lens the highest rating they've ever given any lens.

Apaflo Loc: Anchorage, Alaska

Except the Tamron actually is 600mm and the Canon actually is 400mm. If the shot requires 600mm minimum there is only one choice.

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

A few observations, not directed at any specific individual, but it sometimes helps to do some fact checking before responding, and also to keep comments on the actual topic.

The OP has provided accurate information all on page one, including the original post and a couple of follow up clarifications. Some of the rest of the people in this thread need to learn to read or to do a little bit of easy research.

1) This is the Canon lens specified: http://global.canon/en/c-museum/product/ef262.html

2) This is the Tamron lens: http://www.amazon.com/Tamron-AFA010C700-28-300mm-3-5-6-3-Cameras/dp/B00LC6LMD0

3) It is very clear from the descriptions that these are both full frame lenses, not lenses designed for APS-C cameras which would vignette on a full frame DSLR. All it takes is a simple web search, no need to even ask whether one is a 'crop' sensor lens. Don't guess, do a little research before posting.

4) Don't make comments about Canon cameras, technology, third party lenses designed for Canon using Nikon terminology (FX/DX). It is misleading because it does not apply to the relevant context and just demonstrates a degree of ignorance, or at least implies that likelihood.

5) Check the EXIF data carefully when somebody posts an image with the download option. Most of the EXIF data in these two images seems accurate and consistent, identifying the camera, but the second image includes some conflicting information, it correctly identifies the Tamron lens in one field, and misidentifies it as a Canon EF 90-300mm f/4.5-5.6 in another, which is a very different lens.

So please, ladies and gentlemen, do a little easy fact checking prior to opining and base your opinions on relevant and substantiated information. This is an interesting thread, with much value from several contributors, but is typical of many UHH threads where some of the responses are of significant value, some are merely noise, and some lie somewhere in the ranges of the zone system. Others merely have fifty shades of grey or darker.

Apaflo Loc: Anchorage, Alaska

It communicates correctly, or at least FX/DX does. Keep in mind that this is not just about Canon equipment, but rather a wide topic where Canon was used as the example.


Actually there is nothing in the Exif data that identifies the lens in use. The proprietary MakeNotes meta data does, in two different records. In this case it actually records, in the "Lens Type" tagged record a single integer number from the lens, 213, and from that number the Exif reader program can only know that two different lenses are branded with that number. One is a Canon lens and the other is the Tamron lens. However the MakeNotes data also has a record tagged as "Lens Model", which is not at all ambiguous. It says this is a "TAMRON 28-300mm F/3.5-6.3 Di VC PZD A010" lens, which is indeed unambiguous and not at all confusing.