Blurred images using a *2 convertor

Phil Bennett

Phil Bennett

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Philip
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Guys

Ive been thinking about purchasing a Sigma 120-300 f2.8 or a Sigma 300 f2.8 lens and putting a *2 convertor, which I have already got, on it to give me 600mm at the long end, albeit @ 5.6.

Now heres the question, Ive been playing around with the convertor on my Sigma 70-200 f2.8 to see what the images are like, and they are rubbish, totally blurred on any setting, using a tripod or hand held.

Can a convertor go out of spec, and can you re-calibrate it?, or are these things pretty much foolproof.

Your help will be appreciated

Phil
 
I only have 1 Sigma lens and none of the lens which the convertor works with in the Canon range.

Phil
 
Sorry can't help any further, it should af ok, is there anyone near you that could try it or pop along to your local camera shop and ask to try the 120 out on it to see if that works ok.
Just a thought do you have a cpl filter on the lens.
 
Totally rubbish sounds like there is something wrong, like misfocusing, which can be adjusted by Sigma. But not very good I can well understand. Please post pics with exif data.

I would say that the only combo like that which would work to an acceptable standard would be a very high quality prime with the best TC you can get. Somewthing like a Canon 300L 2.8 with Canon 2x Extender. 2x extenders are very demanding on the quality of the mother lens.

What exactly are you using?
 
have you tried manual focusing to see if it makes any difference?

is the converter solid? by that I mean, there is no movement that shouldnt be there as it something is working loose [the 1.4 TC has built in loose factor, they work loose inside and have to be tightened up from time to time]

how soft is soft? the x2 is reputed to be less good than the smaller tc's and for that reason, I bought the 1.4 to go with siggie 120-300 and its lovely, but depends how soft and blurry you mean?
 
SussexBlue said:
Sorry can't help any further, it should af ok, is there anyone near you that could try it or pop along to your local camera shop and ask to try the 120 out on it to see if that works ok.
Just a thought do you have a cpl filter on the lens.
Click to expand...

I have a UV filter on

Phil
 
HoppyUK said:
Totally rubbish sounds like there is something wrong, like misfocusing, which can be adjusted by Sigma. But not very good I can well understand. Please post pics with exif data.

I would say that the only combo like that which would work to an acceptable standard would be a very high quality prime with the best TC you can get. Somewthing like a Canon 300L 2.8 with Canon 2x Extender. 2x extenders are very demanding on the quality of the mother lens.

What exactly are you using?
Click to expand...

Sigma 70-200mm f2.8 and Sigma APO * 2 convertor

IMG_4977ammended.jpg


Phil
 
Yv said:
have you tried manual focusing to see if it makes any difference?

is the converter solid? by that I mean, there is no movement that shouldnt be there as it something is working loose [the 1.4 TC has built in loose factor, they work loose inside and have to be tightened up from time to time]

how soft is soft? the x2 is reputed to be less good than the smaller tc's and for that reason, I bought the 1.4 to go with siggie 120-300 and its lovely, but depends how soft and blurry you mean?
Click to expand...

Yep, Ive tried MF but still the same

Everything seems tight

The pic Ive posted is about the best one over 2 days Ive been trying

Phil
 
Phil, shutter speed, aperture, camera, filter. What exactly are you using?

Is the filter a cheapy? Take it off and offer it up against one side of a binocular. The filter should be completely invisible. Take some test pictures with and without. Just shots across the room now - a light bulb is quite good, bright enough for a good shutter speed if you raise the ISO, and focusing on the writing on it. I'm suspicious... :thinking:
 
from the posted picture it looks a little like it could still be camera shake.
I have a canon 300mm f4 and bought a 1.4x converter to go with it. Also have a Manfrotto carbon fibre tripod and head. Having upgraded recently to a 50D I've been using the live view mode and zooming in on the subject on the screen and then either using the 2sec timer or a remote release to take the picture after manually focusing.
Its really only when I'm not touching the camera that I get the really sharp results. Even mounted on the tripod I still get a slightly unsharp picture and thats with the image stabilisation on.
Worth remembering that with the extra magnification any hint of movement gets really exagerated through the lens.
 
It's not camera shake.

Canon
Canon EOS 5D Mark II
Adobe Photoshop CS4 Windows
497x600
2009:07:19 13:21:09
2009:07:20 21:30:48
2009:07:19 13:21:09
1/1600"
F7.1
F5.7
0.005 mm
4775.56 m
Manual
0
Multi-segment
Off
640
Auto
400.0 mm
 
admirable said:
It's not camera shake.

Canon
Canon EOS 5D Mark II
Adobe Photoshop CS4 Windows
497x600
2009:07:19 13:21:09
2009:07:20 21:30:48
2009:07:19 13:21:09
1/1600"
F7.1
F5.7
0.005 mm
4775.56 m
Manual
0
Multi-segment
Off
640
Auto
400.0 mm
Click to expand...

And care to explain (y)

Heres a fuller Exif still dont get your point

# Exposure Time (1 / Shutter Speed) = 1/1600 second = 0.00063 second
# Lens F-Number/F-Stop = 71/10 = F7.1
# Exposure Program = manual control (1)
# ISO Speed Ratings = 640
# Exif Version = 0221
# Original Date/Time = 2009:07:19 13:21:09
# Digitization Date/Time = 2009:07:19 13:21:09
# Shutter Speed Value (APEX) = 10643856/1000000
Shutter Speed (Exposure Time) = 1/1600 second
# Aperture Value (APEX) = 5655638/1000000
Aperture = F7.1
# Exposure Bias (EV) = 0/1 = 0
# Max Aperture Value (APEX) = 5/1 = 5
Max Aperture = F5.66
# Metering Mode = pattern / multi-segment (5)
# Flash = Flash did not fire, compulsory flash mode
# Focal Length = 400/1 mm = 400 mm
# Last Modified Subsecond Time = 57
# Original Subsecond Time = 57
# Digitized Subsecond Time = 57
# Colour Space = 65535
# Image Width = 663 pixels
# Image Height = 800 pixels
# Focal Plane X-Resolution = 5616000/1459 = 3849.21
# Focal Plane Y-Resolution = 3744000/958 = 3908.14
# Focal Plane X/Y-Resolution Unit = inch (2)
# Custom Rendered = normal process (0)
# Exposure Mode = manual exposure (1)
# White Balance = auto (0)
# Scene Capture Type = standard (0)
 
Well it's 1/1600 so if it was still shaky the kingfisher would have buggered off with the camera movement! :LOL:
 
Just Dave said:
And care to explain (y)

Heres a fuller Exif still dont get your point

# Exposure Time (1 / Shutter Speed) = 1/1600 second = 0.00063 second
Click to expand...

It's unlikely to be camera shake with a shutter speed of 1/1600sec and TBH it doesn't look like it. Neither does it look like a faulty lens, or poor image quality, at first glance.

It just looks out of focus, and I suspect either the lens is misfocusing, or it could be a faulty filter - a similar post here recently turned out to be a faulty polariser. If a filter is not perfectly flat, they upset long lenses especially.
 
I agree, it looks like oof blurring not camera shake. As suggested I think you need to do some test shots without the filter, though I would have thought at that level of image IQ loss caused by a filter, I would expect you to have noticed some from the lens without the TC fitted, albeit less magnified than it is with....if you see what I mean.
 
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