Bad lens for IR photography?

sumball · 4th October 2006

Hi all,

Learnt from this post http://forums.clubsnap.org/showpost....57&postcount=1 by Pablo that Tamron SP AF 24-135mm f/3.5-5.6 AD aspherical macro is considered as a bad lens (or not a good lens) for IR photography.

Please may I check with the members here who have any opinions the reason this lens is considered as a "bad lens" for IR? Is it due to the hotspot or so?

Yesterdat, I tried my first IR http://forums.clubsnap.org/showthread.php?t=226912 using this lens but the photos cannot show the good or bad of this lens (perhaps I do not know how to differentiate). Therefore, would like to ask for the comments of this lens.

Thanks in advance.

Cheers!

Regards,
CM

ngebor · 4th October 2006

Hi sumball,

You are right, imho, bad lens in IR is mostly refering to hotspot... In some situation, we can't see them, specially when u use high speed (and/or small f-numbers)... Looking at your pics, you may have a little hotspot, but i'm note sure... what was f-number, speed and ISO u use?
You may try bigger f-number, and speed longer than 2 second... if you still cant see the hotspot, then we need to update the list

TrailsofLife · 4th October 2006

Its hard to tell when the weather is bad actually. Most so called bad lenses, can be salvaged with wider aperture. The only one that I encounter that gets hot spot even opened wide is EFS 18-55mm.

From your pix, I think your lens is fine.

4th October 2006	#1
sumball Senior Member Join Date: Jul 2003 Posts: 4,224	Bad lens for IR photography? Hi all, Learnt from this post http://forums.clubsnap.org/showpost....57&postcount=1 by Pablo that Tamron SP AF 24-135mm f/3.5-5.6 AD aspherical macro is considered as a bad lens (or not a good lens) for IR photography. Please may I check with the members here who have any opinions the reason this lens is considered as a "bad lens" for IR? Is it due to the hotspot or so? Yesterdat, I tried my first IR http://forums.clubsnap.org/showthread.php?t=226912 using this lens but the photos cannot show the good or bad of this lens (perhaps I do not know how to differentiate). Therefore, would like to ask for the comments of this lens. Thanks in advance. Cheers! Regards, CM

4th October 2006	#2
ngebor Member Join Date: Jun 2006 Location: Singapore Posts: 314	Re: Bad lens for IR photography? Hi sumball, You are right, imho, bad lens in IR is mostly refering to hotspot... In some situation, we can't see them, specially when u use high speed (and/or small f-numbers)... Looking at your pics, you may have a little hotspot, but i'm note sure... what was f-number, speed and ISO u use? You may try bigger f-number, and speed longer than 2 second... if you still cant see the hotspot, then we need to update the list

4th October 2006	#3
TrailsofLife Senior Member Join Date: Jul 2004 Location: Singapore Posts: 8,492	Re: Bad lens for IR photography? Its hard to tell when the weather is bad actually. Most so called bad lenses, can be salvaged with wider aperture. The only one that I encounter that gets hot spot even opened wide is EFS 18-55mm. From your pix, I think your lens is fine. __________________ *trailsoflife photographyblog**