Images more clear with TC than lens alone?

[Nykon]

Im stumped! I am shooting with a D90 and a 80-200 AF-D with a Kenko 1.4 Pro 300 TC. It seems as though shooting the same object, from a tripod, and remote shutter clicker at 200mm, the images are more clear with the TC on than the straight lens.

I shot through the range of 2.8 - 14 with the lens, then 4 - 16 with the TC attached. Cropped it by 100%, and took a look. Is this normal? I thought I was suppose to lose image quality with the TC?

I can post up all the pics if necessary.

Thanks in advance!

 

[Big Mike]

Are you maybe cropping 'deeper' with the non-TC shots, to make up for the extra magnification that you get with the TC?

Can you show us some examples?

 

[Nykon]

Nope, I zoomed in on Camera Raw to 100% and cropped.

I wont load them all to save on loading time.

With lens only @ 2.8

With lens only @ 5.6

With lens only @ 8

Lens only @ 11

With TC @ 4

With TC @ 6.3

With TC @ 8

With TC @ 11

With TC @ 14

 

[Big Mike]

This is just a guess...but maybe the TC is increasing the DOF, which is bringing those shots closer to actually being in focus. Because none of the shots actually look like they are in focus.

 

[Nykon]

I dont know. Im still new to all this for the most part. At least when it comes to the technical side of this. I know if I were to focus manually it would most likely be worse, just because Im not too good at that. I wonder if I should light the subject up more so the camera can focus easier and try reshooting? Basically, I am trying to figure out where the sweet spot is when shooting with just the lens, then with the TC installed. I've seen that typically with most lenses its around f/8? Could be way off though too, I dont know.

 

[Overread]

Try shooting a flat subject at an angle - when I've done sharpness tests in the past I find it a nightmare to shoot something flat dead on - so I shoot at an angle (say around 45degrees) That way even if your focus is a little bit off you still get a band of the shot that will be in focus.

 

[Garbz]

I tell you right now, none of those images even remotely show the quality that the 80-200 should be capable of. Your images should be tac sharp at 100% on everything except f/2.8 when focused near. Even at f/2.8 the far focus should be tac sharp.

 

[Nykon]

Well I shot a Bluejay from inside my house out the open window with the TC attached, and I was not impressed with the quality. Thats what made me do this little test. I'll have to mess with it some more, I don't use the lens much and it's still rather new. Although I shot a Redsox game, and those pics were TACK! Couldnt have been happier, and I did a lot of cropping too!

 

[Robin Usagani]

the object you are shoooting at has reflectie surface. If you are shooting a mirror, does the lens focus on the object in the mirror or the mirror it self? Just making a point. I would manually fix your focus.

 

[Nykon]

True about the mirror, but this wasn't that reflective. The item I was shooting was a candle holder. I dont know, Im going to play around with the lens a little more and see what happens. Worse case scenario is I will have to send it back to B&H and get the 70-200 with VR. That would be horrible! :razz:

 

[Robin Usagani]

add more light would be nice too

 

[Nykon]

Yeah, the lighting is one of the things I was thinking about. Figured it was giving it focus problems. Although, it wasnt too dark, but it wasnt too bright either.

 

[Big Mike]

Also, make sure that you are not within the lenses minimum focus distance. For example, if you are trying to shoot something that is two feet away, the lens probably can't focus that close. And with the TC attached, the minimum focus distance is probably bigger.

 

[Overread]

As far as I know teleconverters won't change the min or max focusing distances of a lens - they just magnify the image you get through the lens itself.