problem with maximum aperture ...nikon 80-200 f/2.8D

elrafo · Jan 20, 2008

Hi,

I have a D-200 with a 80-200 f/2.8 D. I did great pictures at f/11 and f/16, I love this lens.
Today, I went for a hike and took some picture, the weather was very cold (-15C) but no humidity... as there was some wind on the top of the mountain, and had difficulties to stay steady at 100 iso, I opened at f/2.8 to get a speeder shutter and be sure that there would be no motion blur...Unfortunately, if there is no motion blur, I have found another problem , the picture seems to be glowy-blurry, even if the focus was ok!
my question is, is it bad to use f/2.8 aperture on digital cameras Outside if there is a lot of light even at 1/8000s ?
all the pictures I have taken at f/2.8 today seems blurry, unsharp but infocus, even at + infinite (manual or auto focus). it is like shooting with a compact camera!
the sharpest results are at f/6.3 and more...do you have experimented this kind of problems ?

here is an example full rez of my problem:

http://raphael.lacoste.free.fr/thephotoforum/BOB_0179.JPG

look on the back, the poles look sharp even the rocks on the foreground, but with a blur like in overlay...

shivaswrath · Jan 20, 2008

wondering if that's condensation from the difference in temperature (warm lens, cold air), or possibly your breath causing condensation. . .long shot, but just an idea. . .

elrafo · Jan 21, 2008

actually there was no condensation on the lens, I took another picture of a lake and a forest, and all the branches seems blurry, the other details are sharp ...

Big Mike · Jan 21, 2008

It might be a DOF issue. When shooting at F2.8, your DOF will be at a minimum...so it may be hard to get everything into focus.

Also, many lenses are not at their best at their maximum aperture. They get much better when you stop down. You can test this by taking the same shot at different apertures (best done with a tripod).

elrafo · Jan 21, 2008

thanks! but don't you think there might be also a GLOW issue while shooting digital with a 35mm lens at full aperture ?

Big Mike · Jan 21, 2008

thanks! but don't you think there might be also a GLOW issue while shooting digital with a 35mm lens at full aperture ?

Some older lenses may have issues because the rear element might be somewhat reflective. The light would bounce off of the sensor (which is more reflective than film), then bounce off of the rear of the lens and back again. This might cause things like ghosting, glow or unsharpness. This is why many new lenses have anti-reflective coatings on the rear element.

I don't know if that is your problem here though.

JerryPH · Jan 21, 2008

Salut mon ami,

Yes it seems more a DOF issue. Did you set your focus manually by chance? It's been very cold in Montreal the last few days... was the lens down to outside temps before you took the pics or was it taken out from under your jacket for a few min and then shots taken?

elrafo · Jan 21, 2008

Hey Mister

bien oui, en fait, the lens was outside during all the trip, the focus was auto and at + infinite... maybe at 200mm it is safer to use 11 or f/16 ...

JerryPH · Jan 21, 2008

elrafo said:
Hey Mister

bien oui, en fait, the lens was outside during all the trip, the focus was auto and at + infinite... maybe at 200mm it is safer to use 11 or f/16 ...

Depends on the lens. On some cases, the sweet spot of the lens is a lot closer to f/8.

Was maybe something fogged up or frozen inside by chance?

elrafo · Jan 21, 2008

the lens is a good one, 80-200 f/2.8 constant D... I think it was not frozen, but I didn't check inside!
with lower light, it looks good but not for Far elements I tried to focus on, wiered ...

Sw1tchFX · Jan 21, 2008

this thread is useless without an image at 100% size. Whether it be the original file or a crop from it.

Garbz · Jan 22, 2008

Note the lens is not all that hot at 200mm at f/2.8 It suffers from quite a bit of CA which can be fixed by stopping down to f/3.5. But my pictures aren't as bad as this.

As it's literally glowing I have only one explanation. Condensation on the lens, if only slight. It doesn't need to fog up the front, but this is basically what a true "soft focus" type effect gives. Detail with glow caused by a film or something on the front element. I have no other suggestions.