Apaflo Loc: Anchorage, Alaska

Do you think any other zoom with a 10X range is better?

If sharp high quality images are the intent, avoid any zoom with more than a 5x range, and don't normally go more than 3X or 4X if possible. That is for 16x20 prints, but for 4x6 prints in grandma's family album you might as well go for the convenience of a 10x or greater superzoom.

oldtigger Loc: Roanoke Virginia-USA

Never thought of it from that standpoint, but it sounds reasonable.

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

Floyd, you are a clever guy, but are just fundamentally wrong in your interpretation of this matter. You are welcome to your opinion, but it is merely opinion without defensible supporting evidence, which should not include 'alternative facts' nor selected points to support your opinion.

I asked you to cite evidence that that specifies exactly what is an accepted formal standard for Exif data that excludes other meta data? You failed to address that. Here is the Exif spec: http://www.exiv2.org/Exif2-2.PDF that explicitly provides for the inclusion of maker note tags. These are clearly meta data items but are also definitively part of the Exif standard.

As for the rest, the complete Exif data for the image in question clearly shows contradictory lens type information as I have demonstrated. I'm not trying to criticize your expertise or the value that much/many of your contributions provide, but some of it does not pass peer review.

In a discussion of this type and in this specific thread the use of Nikon specific terminology is not appropriate as I and others have said. Your selective use of certain Exif data records to support your point while ignoring other conflicting information undermines your entire contribution which is unfortunate because most of what you say is very good.

Exiftool is merely a single source of information, it is not the credible source . http://www.sno.phy.queensu.ca/~phil/exiftool/

Exiftool is excellent, but it is merely one tool among many that can be used to explore and interpret Exif data. There are others that are equally as valid. The credible source of information is the complete Exifdata, not a single record, nor the tool used to investigate the data. It is very clear that the actual Exif data set includes conflicting and unclear information.

And to your final point, I have used multiple tools beginning with Exiftool and then verifying with other tools to confirm my analysis.

So back to you Barrow Boy, sorry Utqiaġvik Boy, your need to wake up yourself and pay more attention to the actual and full detail. If you were willing to moderate your style a little it would benefit your contributions and value to this site, but you are not the font of ALL wisdom. Note that my initial post in this thread explicitly did not cite any individual's response, merely a request to do a little more thorough research prior to opining.

You seem to get a little upset when people criticize your viewpoints rather than working with them to deliver a better set of responses. You have much value to add, but this is not the best way to achieve that.

mwsilvers Loc: Central New Jersey

For the most part, I agree that focus breathing is not necessarily a significant issue, but depending on your expectations and requirements for a lens it could be. Comparing two different 18-200 superzoom lenses, for instance, could result in significant size differences at various focal lengths at distances less than infinity. One should at least be aware of this phenomena. Too often people accuse the lens manufacturer of lying about the focal range of a lens when they shoot some object 8 feet away and realize the image is far smaller than they expected.

steve_stoneblossom Loc: Rhode Island, USA

Agreed.

Apaflo Loc: Anchorage, Alaska

If I am wrong why can't you show where! Look at the dishonesty you engage to deny the facts (not opinions) I post.

"I asked you to cite evidence that that specifies exactly what is an accepted formal standard for Exif data that excludes other meta data? You failed to address that. Here is the Exif spec: http://www.exiv2.org/Exif2-2.PDF that explicitly provides for the inclusion of maker note tags. These are clearly meta data items but are also definitively part of the Exif standard."

You didn't even know about that document until I cited it, gave you the specific document title to search for and told you it could be downloaded! Now you say that I didn't address that issue. You have not even read it! Where does it specify a "Lens Model" record tag?

And then once again you repeat this:

"As for the rest, the complete Exif data for the image in question clearly shows contradictory lens type information as I have demonstrated."

As shown very clearly the actual data is not what you provide, is not contradictory, and instead is logically very clear and very specific.

Then you again start on these hilarious attempts at intimidation by Ad Hominem, and from there continue on with more opinion rather than fact, sprinkled with gratuitous personal discussion that you fabricate. Keep your opinions if you like, but you need to try a few real facts for discussion. Here is an example of the problem:

"Your selective use of certain Exif data records to support your point while ignoring other conflicting information ..."

I have shown you every single meta data record attached to the example image that relates to the lens. There are no others to be ignored. And certainly you have 1) not shown any others and 2) have repeatedly both ignored existing meta data and mischaracterized it.

Then we get this type of bogus claim:

"Exiftool is merely a single source of information, it is not the credible source . http://www.sno.phy.queensu.ca/~phil/exiftool/

Exiftool is excellent, but it is merely one tool among many that can be used to explore and interpret Exif data. There are others that are equally as valid. The credible source of information is the complete Exifdata, not a single record, nor the tool used to investigate the data. It is very clear that the actual Exif data set includes conflicting and unclear information."

Exiftool actually is a credible source, but it wasn't used as a source! It was used to extract the exact data from the image file. The difference is that you are confused by data that comes from other sources and not from the image file.

Yet after you have been provided specific instructions on how to use Exiftool to find and extract data, but still can't do it right, you claim this:

"And to your final point, I have used multiple tools beginning with Exiftool and then verifying with other tools to confirm my analysis."

We know you didn't use Exiftool to begin with. We know you still don't quite understand what it does differently than other Exif tools.

Unless you can skip your bogus opinions, cite verifiable facts from credible sources, be honest and refrain from gratuitous personal discussion, there are no technical issues unresolved beyond any shadow of doubt here. As long as that remains true there is no reason for me to respond further.

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

Floyd, I accept your surrender! You simply do not understand the issue here. Some of the technical details perhaps, but the bigger picture, I think not.

waegwan Loc: Mae Won Li

I don't think it is Tamron lens issue per se but rather a focus breathing lens compared to a non focus breathing lens. I didn't know about focus breathing until I stsrted this thread. More to come :)

waegwan Loc: Mae Won Li

Hello Everyone and thanks to everyone for your input. I believe the focus breathing is what caused the difference in my original post and unless shots are at room distance or less it is not an issue. Again, the lenses used were Canon 100-300 f/5.6L and Tamron 28-300 Di VC PZD. The Tamron focal length marks on the barrel leave a little more to play with than the Canon lens so a few of the Tamron shots are not exactly at 200 and 100 but even at that there is no appreciable different in subject size in the frame between the two lenses. The Camera was fixed on a tripod and all I did was change lenses so there is no forward or back movement on the camera body. So here what I came up with. I did the test at 300mm, 200mm and 100mm on both lenses with targets at 500 yards, 150 yards and 30 yards. I can only upload 10 files here so I selected the 300mm test. The 200mm and 100mm test have the same results.

Canon 300mm at 500 yards

(Download)

Tamron 300mm at 500 yards

(Download)

Canon 300mm at 150 yards

(Download)

Tamron 300mm at 150 yards

(Download)

Canon 300mm at 30 yards

(Download)

Tamron 300mm at 30 yards

(Download)