All Forum Comments
Now on ebay here. Sale closed here.
Comment by edumad posted on Helios 300mm F4.5 at 16/04/2010 - 12:07
Try to press Chris at SRS to see if he can get a rental on a DA*300mm by then.
Comment by edumad posted on Advice Required for 300mm Prime at 16/04/2010 - 10:53
Here is a picture of the crack on the hood.
Comment by edumad posted on FS: Sigma 28-70mm F2.8-4 at 15/04/2010 - 12:38
AAAHhhhh! My eyes... where's the bleach?!?
Comment by edumad posted on I shot to Grey Squiggles today! at 13/04/2010 - 13:37
Final drop before ebay: £45 shipped to UK.
Comment by edumad posted on Helios 300mm F4.5 at 11/04/2010 - 20:59
What property of the lens defines resolution?
What I can see is two lenses that can direct the light so that the same item is described by the same pixels. At least the demarcation between contrasting areas seems to be well done on both.
But for the same pixels one lens can display more information than the other.
Its strange it seems a property of the sensor not lens , but here sensor is the same...
What I can see is two lenses that can direct the light so that the same item is described by the same pixels. At least the demarcation between contrasting areas seems to be well done on both.
But for the same pixels one lens can display more information than the other.
Its strange it seems a property of the sensor not lens , but here sensor is the same...
Comment by edumad posted on Sharpness? resolution? contrast? at 10/04/2010 - 20:49
I have lenses with dust inside and two with scratches (CZJ and Pentax 135mm) and no discernible effect.
Comment by edumad posted on Dust inside the lens at 09/04/2010 - 22:11
As you know, I was having some focus problems, so I did some test shots.
It was then that I realized that the Takumar 135mm F2.5 Bayonet gave better results that the Tamron 24-135mm at 135mm.
Takumar 135mm F2.5 Bayonet, ISO100, F4, 1/160, ~200% crop
[IMG]http://farm3.static.flickr.com/2702/4503747628_d402288e22_o.jpg[/IMG]
Tamron, ISO100, F4, 1/160, ~200%
[IMG]http://farm3.static.flickr.com/2791/4503118161_d108536a4b_o.jpg[/IMG]
My reaction was to say that the Pentax is sharper, but that isn't really the case.
There is no discernible difference in ability to resolve shapes and the lines that distinguish them. That is at least for regions with very different colours.
Because you can see the Pentax can give more detail overall, like in the bottom part of the tower were that is very clear.
But my question is, what property is this? Sharpness? Is it contrast?
The exposure parameters are equal but the image is darker for the Tamron, poor hability to resolve detail in shadows?
It was then that I realized that the Takumar 135mm F2.5 Bayonet gave better results that the Tamron 24-135mm at 135mm.
Takumar 135mm F2.5 Bayonet, ISO100, F4, 1/160, ~200% crop
[IMG]http://farm3.static.flickr.com/2702/4503747628_d402288e22_o.jpg[/IMG]
Tamron, ISO100, F4, 1/160, ~200%
[IMG]http://farm3.static.flickr.com/2791/4503118161_d108536a4b_o.jpg[/IMG]
My reaction was to say that the Pentax is sharper, but that isn't really the case.
There is no discernible difference in ability to resolve shapes and the lines that distinguish them. That is at least for regions with very different colours.
Because you can see the Pentax can give more detail overall, like in the bottom part of the tower were that is very clear.
But my question is, what property is this? Sharpness? Is it contrast?
The exposure parameters are equal but the image is darker for the Tamron, poor hability to resolve detail in shadows?
Comment by edumad posted on Sharpness? resolution? contrast? at 09/04/2010 - 21:49
I'm pretty sure that last time I really did hit infinity, but maybe I was wrong.
I shot this with the SMC tak bayonette focus indicator came on, which was very very close to infinity.
135mm F4 ISO100
And I shot this one, just pushed to infinity.
135mm F4 ISO100
What I observed was that the autofocus detector is actually active within a certain range (while you change the focus). The photo from farther towards infinity (in that range) was better, but still not as good as infinity. Infinity itself was not detected to be in the range of focus.
The Tamron 24-135mm at 135mm gives this while MF
135mm F5.6 ISO100
From the scale it seems to be on infinity
But this lens has more slack to go beyond infinity, this is taken at the limit of the lens past infinity
It isn't supper obvious but the rooftop is slightly sharper here then when infinity is focused.
So the problem seems to relate with the auto focus detection. However super close to infinity should be well past the roof... which makes it very strange that the roof is so in focus. At F4, the roof should not be at or past the hyperfocal point either.
I shot this with the SMC tak bayonette focus indicator came on, which was very very close to infinity.
135mm F4 ISO100
And I shot this one, just pushed to infinity.
135mm F4 ISO100
What I observed was that the autofocus detector is actually active within a certain range (while you change the focus). The photo from farther towards infinity (in that range) was better, but still not as good as infinity. Infinity itself was not detected to be in the range of focus.
The Tamron 24-135mm at 135mm gives this while MF
135mm F5.6 ISO100
From the scale it seems to be on infinity
But this lens has more slack to go beyond infinity, this is taken at the limit of the lens past infinity
It isn't supper obvious but the rooftop is slightly sharper here then when infinity is focused.
So the problem seems to relate with the auto focus detection. However super close to infinity should be well past the roof... which makes it very strange that the roof is so in focus. At F4, the roof should not be at or past the hyperfocal point either.
Comment by edumad posted on Strange focusing at 08/04/2010 - 20:42
DOH!
Never get angry and post... My anger blinded me. It should read, "since buying my 2001 Punto", I actually bought it Fev 2008.
So not so great... Mike-P.
Don't talk about how good your cars have been, I want horror stories, I wanna feel better
Never get angry and post... My anger blinded me. It should read, "since buying my 2001 Punto", I actually bought it Fev 2008.
So not so great... Mike-P.
Don't talk about how good your cars have been, I want horror stories, I wanna feel better
