Canon 70-200mm 2.8 with 1.4 tele converter

[prodigy2k7]

So... If you have the 1.4x tele-converter, or any converter, they say you lose one stop for example. Does that mean you can't use f/2.8 anymore and must use f/4? Or does it mean you can use f/2.8 but you lose one stop of light, so your shutter speed will be lower at f/2.8...

Can someone clarify please?

 

[matt hougaboom]

Yes to your first statement kiss 2.8 goodbye

 

[dhilberg]

Right. That means your maximum aperture is one stop less with the teleconverter, which turns your f/2.8 into an f/4. It's a drawback of using a teleconverter.

 

[Garbz]

Hard to say based on the comment. 'you can't used f/2.8 anymore' Yes you can. the teleconverter though makes this appear as f/4 to the camera. Depending on the converter itself it may even show up as f/4 on the camera, or it may still show up as f/2.8 but the point is the same. One stop of light is lost.

That said that doesn't stop me using my Nikkor 80-200 with the Kenko 1.4x teleconverter. They make a wonderful combination.

 

[icassell]

If you have a 2X converter, you lose 2 stops. I still frequently use my Sigma EX converters (I have both the 1.4x and the 2x) and love them. There is no other way I could afford a 600 mm lens (I use the 2X with my 100-300mm f4) and I have a good tripod.

 

[JerryPH]

If most people use ISO 100 at F/2.8, most people can safely go to ISO 200 at F/4 and get the exact same exposure. Where it starts to get iffy is if you have a 2X teleconverter and need to set things to ISO 400 at F/5.6 to get the picture you can get at ISO 100 and F/2.8. DOF in most cases will always be very close to the same... meaning quite shallow, but there is a lot of magnification happening here, so that's an unavoidable side effect.

 

[Overread]

yep you might lose a stop of light but f4 is still a very usable aperture. I freaquently use my 70-200mm f2.8 with a 1.4 teleconverter to get some more range out of it and the loss of one stop of light is not too much to worry about.
A 2* teleconverter is a little bit different, whilst 2 stops of light loss mean its best used in brighter conditions the softness added can be a limiting factor - however mid and top level camera bodies deal with this better (produce sharper results) than lowerend (rebel) series bodies. (its to do with the pixies inside --- er pixels)
Some 3rd party teleconverters are not good reporters which means that the camera never knows they are there - so it would still let you shoot with f2.8 - but the teleconverter has already taken the light away so you don't get it back.

 

[icassell]

Pixies in the camera? So that explains it! no wonder my images don't look like I want them too!

 

[Ptyler22]

I thought with a 2x tele-converter you loose one full stop, but with a 1.4x I thought it was only a half stop? am I wrong?

 

[Overread]

sorry
1 full stop lost with a 1.4*
2 full stops lost with a 2*
wish it was only half a stop - maybe oneday.....

 

[icassell]

... and an obscene amount lost when I stack my 1.4x and my 2x

 

[Ptyler22]

sorry
1 full stop lost with a 1.4*
2 full stops lost with a 2*
wish it was only half a stop - maybe oneday.....

Oh, I see, ya I'll bet in a few years, cameras will be insane. Probably like zero noise at ISO 12800, who knows how high the ISO will go, 2.8's will be obsolete because of how high the ISO will go. It's going to be awesome .

 

[Big Mike]

I believe that with the Canon TCs, the camera display will not go down to F2.8, so it's giving you the effective aperture. With an off-brand TC (I've got a Tamron 2X) the camera will still display F2.8 but the shutter speed drops because of the the two stop loss of light.