Weird

[KLthree]

Hi all,

I have a Tamron 17-50 f2.8 on a Canon body. Yesterday, I bought a Teleplus 2x Teleconverter for my Tele lens and I combined the Tamron and the teleconverter to take some shots.

It was when reviewing the shots then I realised that the f-stop (2.8) remained the same even though I had the teleconverter on. But for the tele lens that I had, the f-stop dropped from f4 (orig. max) to f8 (dropped 2 stops) - which I know is the norm.

Why didn't the Tamron 17-50 f2.8 experience any drop in f-stop like the tele lens? Is it because the teleconverter was not supposed to be used on the Tamro?

Please help!

[Snoweagle]

Originally Posted by KLthree Hi all, I have a Tamron 17-50 f2.8 on a Canon body. Yesterday, I bought a Teleplus 2x Teleconverter for my Tele lens and I combined the Tamron and the teleconverter to take some shots. It was when reviewing the shots then I realised that the f-stop (2.8) remained the same even though I had the teleconverter on. But for the tele lens that I had, the f-stop dropped from f4 (orig. max) to f8 (dropped 2 stops) - which I know is the norm. Why didn't the Tamron 17-50 f2.8 experience any drop in f-stop like the tele lens? Is it because the teleconverter was not supposed to be used on the Tamro? Please help!

If the aperture doesn't reduce even after putting on the teleconverter, isn't it a gd thing?

[night86mare]

Originally Posted by KLthree Hi all, I have a Tamron 17-50 f2.8 on a Canon body. Yesterday, I bought a Teleplus 2x Teleconverter for my Tele lens and I combined the Tamron and the teleconverter to take some shots. It was when reviewing the shots then I realised that the f-stop (2.8) remained the same even though I had the teleconverter on. But for the tele lens that I had, the f-stop dropped from f4 (orig. max) to f8 (dropped 2 stops) - which I know is the norm. Why didn't the Tamron 17-50 f2.8 experience any drop in f-stop like the tele lens? Is it because the teleconverter was not supposed to be used on the Tamro? Please help!

please show pictures along with exif data intact.

there is no point claiming that this is true without any proof or basis, because no one will believe you. i know i don't, because humans tend to make mistakes.

[KLthree]

Originally Posted by night86mare please show pictures along with exif data intact. there is no point claiming that this is true without any proof or basis, because no one will believe you. i know i don't, because humans tend to make mistakes.

Hi,

I am new to photography and have no idea how to post an image with exif data. But I am sure that my f-stop values shown on my dslr screen did not change with the Tamron lens. It stayed at f2.8. I am new but not that idiotic as to not be able to read my f-values on my dslr. I tried again last night and it was the same thing - on my 70-200mm, the f-stop dropped from f4 to f8 max. But on the Tamron, it still showed that I have f2.8 as my max aperture. In fact, it was the same on my Canon 50mm f1.8... The dslr screen still showed that I have a max aperture of f1.8...

I am not claiming anything like you said, just wanted some advice on why this is happening, if you are not willing to help, then don't. It's not like I made up this lie/claim to show everyone that I have a wonderful piece of equipment or something. Just needed some help on why I am not experiencing any drop in f-stops on some lenses.

[KLthree]

Originally Posted by Snoweagle If the aperture doesn't reduce even after putting on the teleconverter, isn't it a gd thing?

Hi Snoweagle,

Thanks, I find that is is indeed a good thing as I still am able to enjoy the benefits of a larger aperture - unless the screen is telling me lies. Maybe I should learn to check the exif data or something to determine if the Tamron lens did indeed retain its max aperture after coupling with a teleconverter

[Snoweagle]

Originally Posted by KLthree Hi Snoweagle, Thanks, I find that is is indeed a good thing as I still am able to enjoy the benefits of a larger aperture - unless the screen is telling me lies. Maybe I should learn to check the exif data or something to determine if the Tamron lens did indeed retain its max aperture after coupling with a teleconverter

Exif data's very impt for lens information. U should check it.

[night86mare]

Originally Posted by KLthree I am not claiming anything like you said, just wanted some advice on why this is happening, if you are not willing to help, then don't. It's not like I made up this lie/claim to show everyone that I have a wonderful piece of equipment or something. Just needed some help on why I am not experiencing any drop in f-stops on some lenses.

you are misunderstanding my post, i am telling you what people will think, that is why you have so little replies to your post.

as to how to post exif data intact, when you resize in photoshop, don't save to web, just save as a new file, and smaller, that will help.

[night86mare]

anyways, when you add the teleconverter, and take photos at the same manual settings, is there any change in exposure?

it could be a compatibility issue, resulting in no change in communication between lens and body, rather than there being no fall-off, but i am just guessing.

how come uncle catchlights never help?

[geeteethree]

teleplus 2x teleconverter is the converter you put on at the front of the lens pretty sure. The same converter that degrades image quality and you probably bought for a ridiculous price of what it is not worth.
I could be wrong

[geeteethree]

sorry, im wrong
thats the kenko 2x aha
it does have compatibility issues with the exif data and communicating with the body.

[T.A.]

It happens when the lens can't communicate with the TC to provide the proper f value.
With the TC on, you'd still notice that your VF had gone darker than when without.

Your cam will meter properly irregardless of the f value, give it a try again with a fixed
ISO setting. Notice the difference in shutter speed with and without the TC.