400mm f5.6 lens vs 200mm f2.8 lens with 2x teleconverter

Hi folks, I have a question about quality.

I have a Sigma 135-400mm f4.5-5.6 lens (it's 5.6 at over 200mm). I almost
always only use this to shoot motorsports outdoors.

I also have a Nikon 80-200mm f2.8 lens.

I'm considering selling the Sigma lens, and buying a Nikon TC-20E II
teleconverter (the money should be comparible). This would, effectively,
turn the Nikon lens to a 160-400mm f5.6 lens for those times I need a longer
lens. One less heavy lens to schlump around the track, and from a strict
numbers point of view, it should give me the same lens length and speed as
the Sigma.

But I'm wondering about quality or other detrimental effects of using the
teleconverter. I've never used one before. Will the image sharpness,
contrast, colour, etc. be comparible to the Sigma lens, or do I pay a cost
besides the stops?

Thanks in advance!
Greg

In article 3LpYc.251265$M95.155288@pd7tw1no, greg
wrote:

I have a Sigma 135-400mm f4.5-5.6 lens (it's 5.6 at over 200mm). I almost
always only use this to shoot motorsports outdoors.

You have my deepest sympathy.

I'm considering selling the Sigma lens, and buying a Nikon TC-20E II
teleconverter (the money should be comparible). This would, effectively,
turn the Nikon lens to a 160-400mm f5.6 lens for those times I need a longer
lens. One less heavy lens to schlump around the track, and from a strict
numbers point of view, it should give me the same lens length and speed as
the Sigma.

You're best to avoid converters with anybody's lens.

In article 3LpYc.251265$M95.155288@pd7tw1no, greg
wrote:

I have a Sigma 135-400mm f4.5-5.6 lens (it's 5.6 at over 200mm). I almost
always only use this to shoot motorsports outdoors.

You have my deepest sympathy.

I'm considering selling the Sigma lens, and buying a Nikon TC-20E II
teleconverter (the money should be comparible). This would, effectively,
turn the Nikon lens to a 160-400mm f5.6 lens for those times I need a longer
lens. One less heavy lens to schlump around the track, and from a strict
numbers point of view, it should give me the same lens length and speed as
the Sigma.

You're best to avoid converters with anybody's lens.

Will the image sharpness,
contrast, colour, etc. be comparible to the Sigma lens, or do I pay a cost
besides the stops?

Greg-

Of course you pay a cost. The question is whether that cost results in
acceptable images compared to images from the Sigma lens. It could go either
way.

Do you use the Sigma at maximum zoom most of the time? If not, then use of the
Nikon alone may meet most of your needs and probably produce better images.
Use of the teleconverter would then be an option.

Fred

Will the image sharpness,
contrast, colour, etc. be comparible to the Sigma lens, or do I pay a cost
besides the stops?

Greg-

Of course you pay a cost. The question is whether that cost results in
acceptable images compared to images from the Sigma lens. It could go either
way.

Do you use the Sigma at maximum zoom most of the time? If not, then use of the
Nikon alone may meet most of your needs and probably produce better images.
Use of the teleconverter would then be an option.

Fred

On Sun, 29 Aug 2004 15:01:50 -0700, Randall Ainsworth
wrote:

You're best to avoid converters with anybody's lens.

I disagree.

Although, I will admit that less conversion is usually better.

Anyway, a Nikon TC-14EII (1.4 conversion factor) with a Nikkor VR
70-200mm f/2.8G produces satisfactory results.

For example:

http://www.xmission.com/~hound/astro...e/bald_003.htm

http://www.xmission.com/~hound/astro...golden_001.htm

-Astro

On Sun, 29 Aug 2004 15:01:50 -0700, Randall Ainsworth
wrote:

You're best to avoid converters with anybody's lens.

I disagree.

Although, I will admit that less conversion is usually better.

Anyway, a Nikon TC-14EII (1.4 conversion factor) with a Nikkor VR
70-200mm f/2.8G produces satisfactory results.

For example:

http://www.xmission.com/~hound/astro...e/bald_003.htm

http://www.xmission.com/~hound/astro...golden_001.htm

-Astro

In message 3LpYc.251265$M95.155288@pd7tw1no,
"greg" wrote:

But I'm wondering about quality or other detrimental effects of using the
teleconverter. I've never used one before. Will the image sharpness,
contrast, colour, etc. be comparible to the Sigma lens, or do I pay a cost
besides the stops?

Compare the MTF charts. If the nikon is about half as far as the sigma
is from the top of the chart, then the combo should be about equally
sharp. If the MTFs are about the same, then you will go much softer
with the combo.
--


John P Sheehy

In message 3LpYc.251265$M95.155288@pd7tw1no,
"greg" wrote:

But I'm wondering about quality or other detrimental effects of using the
teleconverter. I've never used one before. Will the image sharpness,
contrast, colour, etc. be comparible to the Sigma lens, or do I pay a cost
besides the stops?

Compare the MTF charts. If the nikon is about half as far as the sigma
is from the top of the chart, then the combo should be about equally
sharp. If the MTFs are about the same, then you will go much softer
with the combo.
--


John P Sheehy

In message ,
AstroPax wrote:

On Sun, 29 Aug 2004 15:01:50 -0700, Randall Ainsworth
wrote:

You're best to avoid converters with anybody's lens.

I disagree.

Although, I will admit that less conversion is usually better.

Anyway, a Nikon TC-14EII (1.4 conversion factor) with a Nikkor VR
70-200mm f/2.8G produces satisfactory results.

For example:

http://www.xmission.com/~hound/astro...e/bald_003.htm

http://www.xmission.com/~hound/astro...golden_001.htm

Are those crops of original pixels?

If not, we can't tell anything about your TC from a shrunk-down image.
You've then shrunk away most of its effect!
--


John P Sheehy