vignetting on 150-600 sigma and tamron

[paulbrogden10]

Hello

I am writing to you to ask what are the differences in vignetting in these two lenses.?

has any one chosen the tamron over the sigma s or c because of this issue.

Also would any one go for the c over the s?

[Waddizzle]

"...  it was the Sigma 150-500mm."

Oh, yes the Sigma 150-500mm.  I have a love/hate relationship with that lens.  I have had three of them.  The one I have now is very good.  Good mind you not great but for that lens, good is great!

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Me, too.  I loved to hate it, too.  It seemed the AF and OS were always in a tug-of-war of some kind.  It was good when it wasn't moving, though, 

But,  really disliked the bokeh.  It looked more like motion blur of overlapping images than anything else to me.

[ebiggs1]

"It seemed the AF and OS were always in a tug-of-war of some kind."

My first one was so bad it would jump a hummingbird clear our of the frame.   The one you have seems a little soft.  Maybe why you dislike the BG OOF so much.  All three of the ones I had, still have one, went back to Sigma for service.  They never did correct the first one.  I sold it for $150 bucks with the warning about the OS.  The second one was replaced by Sigma because of a long complicated warranty, no warranty dispute.  It was quite to my surprise.  But it is a pretty darn good lens. It now lives on my 1D Mk II N.

Sigma has gone through a complete transformation in the CS department.  It was from none existent to pretty good now.  Not in the same class as Canon but it is better.

As a side note, I see Canon is coming out with a EF 200-600mm f5.6 to compete and stop the bleeding from Tamron and SIgma in this lens category.  You know brand-N already has one.

[Waddizzle]

"As a side note, I see Canon is coming out with a EF 200-600mm f5.6 to compete and stop the bleeding from Tamron and SIgma in this lens category.  You know brand-N already has one."

At that speed, unless the lens is as sharp as an electron microscope, Canon would be wise to include Image Stabilzation.

[EDIT]  BTW, the AF vs. OS tug-of-war was in full tilt when I took those shots.  I could hear something churning away.  I eventually figured out that I could get sharper hand-held photos, no panning, if I turned OS off.

[ebiggs1]

"I eventually figured out that I could get sharper hand-held photos, ... if I turned OS off."

From your examples, it does look like your lens was soft.  Mine is sharper but I went through three of them to get it.  I am not sure OS or IS or VC effects IQ in itself.  Whether it is on or off the light path goes through the same amount of glass.  My problem caused a subject to jump clear out of the frame. Obviously not a good thing but the shots were decently sharp for a cheap lens.

I bet a Canon EF 200-600mm f5.6 will have IS.  It has to compete with the Nikkor 200-500mm, the Sigma and Tamron.

It may not be an "L", however.

[ebiggs1]

"... it seemed to vignette on underexposed shots"

Vignetting will appear worse when the shot is underexposed.  It isn't the lens getting worse.  It is the exposure error getting worse.

"Some don't need to be wide open, either.  But, most anything short of catastropic failure seems to be correctable."

Absolutely.

"... regardless of focal length or aperture."

Generally super tele zooms don't exhibit the problem as the aperture is stopped down.  On some it is not a concern with just one stop from wide open.  Even prime teles can and do show this issue, too.

[Waddizzle]

"... it seemed to vignette on underexposed shots"

Vignetting will appear worse when the shot is underexposed.  It isn't the lens getting worse.  It is the exposure error getting worse.

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It is not a matter of underexposure error at all.  I have occasionally mentioned that I find need to "shoot to the left", instead of shooting to the right.  Shooting at a white bird in flight against a blue sky background is a perfect example of it.

The camera's metering perfectly exposes the blue of the sky, while washing out much of the white details of the gull.  You have to back off exposure somewhere between 1/3 and a full stop, to not washout the whtie details. 

In this case and the previous example, I underexposed by a full stop.  The above shot used the same exposure and zoom settings as the previous example.  The original shot showed similar vignetting, and this image has been cropped.  In hindsight, maybe a 2/3 of stop would have been ideal.  I have not re-adusted the exposure in post.  It appears a little dark to me.

[ebiggs1]

"It is not a matter of underexposure error at all."

Yes it is.  You really need to learn how to read and use the  histogram.  To actually say I always, or I always need to, shoot to  the right or left is totally missing the point.

The histogram is basically a graph showing the distribution of light in your images, from the shadows to the highlights. The left side of the graph represents the darkest shadows in the image whilst the right side represents the brightest highlights.  A good exposure is one that keeps all that information within the confines of the graph. If the graph is sliding off the scale to the left, you are losing shadow detail, conversely if it is sliding off to the right you are “blowing” the highlights.

I hesitate to advise you since you don't accept constructive criticism well I think it best to refrain.  However, it would be easy to correct that shot and that type shot.  Even the one you have can be fixed in post.

[Waddizzle]

"I hesitate to advise you since you don't accept constructive criticism well I think it best to refrain." 

Actually, you do don't offer constructive criticism.  Not even close.  Condescension is more accurate.  Believe it or not, I know exactly what historgrams are, and how to use them to correct exposures. 

BTW, that's the histogram fo the shot you have been so critical off.  It shows exactly what you say it should show.   It is dead in the middle, and it was shot a full stop below what the camera was metering.

Like i said, the metering in the camera is mostly setting exposure on the dark blue sky, which overexposes the details of white bird.  One must recognize these scenarios ahead of time.  In fact, I used the histogram in the camera to cheack the exposure, and then determine how much to underexpose subsequent shots aimed at the sky  Any questions..

[ebiggs1]

I abstain. Have it your way.  

[Waddizzle]

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@ebiggs1 wrote:

I abstain. Have it your way.  

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""It is not a matter of underexposure error at all."

Yes it is.  You really need to learn how to read and use the  histogram.  To actually say I always, or I always need to, shoot to  the right or left is totally missing the point."

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Thank-you.  BTW, I never said that, either.  But, it is exactly what you "heard" me say.  Peace.