Lenses usable for infrared photography?

JoepLX3 · 10-09-2010, 11:21 AM

Originally posted by Digitalis

avoid ultrawide lenses with infrared, because not only hot spots you will also likely encounter some serious smearing due to the fact that IR wavelengths aren't as easily bent as visible light wavelengths are.

That's a pity, but understandably true...

So filter needs to fit on my 18-55 mm II kit lens and some fast A prime.

Are there hudge differences between IR filters and IR filters?
- Which type / brand should I get (best bang for the buck)?

I found a Dutch company that sell them (720 nm) NEW up 67 mm diameter from stock for less than 30 Euro's, including transport costs (they can also "make" bigger, but that takes time and at higher cost).

creampuff · 10-09-2010, 05:08 PM

Originally posted by Digitalis

avoid ultrawide lenses with infrared, because not only hot spots you will also likely encounter some serious smearing due to the fact that IR wavelengths aren't as easily bent as visible light wavelengths are.

Do you have specific examples of what this "smearing" is all about? Can you elaborate what the "smearing" should look like?
I myself have used an ultrawide like the DA 14mm with no issues and I know of other IR shooters using other brands with ultrawides who have not mentioned this issue.

IR modded *ist DL2 with DA 14mm f/2.8

creampuff · 10-09-2010, 05:14 PM

Originally posted by JoepLX3

That's a pity, but understandably true...

So filter needs to fit on my 18-55 mm II kit lens and some fast A prime.

Are there hudge differences between IR filters and IR filters?
- Which type / brand should I get (best bang for the buck)?

I found a Dutch company that sell them (720 nm) NEW up 67 mm diameter from stock for less than 30 Euro's, including transport costs (they can also "make" bigger, but that takes time and at higher cost).

I have used external IR filters from Hoya, Cokin, B+W and generic made in China ones and even though they may all list a somewhat similar cutoff wavelength, they ALL show a different color/spectral rendition. Exposure times vary too.

JoepLX3 · 10-09-2010, 05:34 PM

Originally posted by creampuff

I have used external IR filters from Hoya, Cokin, B+W and generic made in China ones and even though they may all list a somewhat similar cutoff wavelength, they ALL show a different color/spectral rendition. Exposure times vary too.

The spectral bandwidth of those filters is typically pretty narrow and I don't see how one centered around 715 nm is better or worse than one centered around 730 nm. The effective width will determine the exposure time, but I (as you might expect) doubt impact on IQ...

**Digitalis** · 10-09-2010, 05:42 PM

Originally posted by creampuff

Do you have specific examples of what this "smearing" is all about? Can you elaborate what the "smearing" should look like?
I myself have used an ultrawide like the DA 14mm with no issues and I know of other IR shooters using other brands with ultrawides who have not mentioned this issue. IR modded *ist DL2 with DA 14mm f/2.8

nice shot, I have seen this smearing with the sigma 12-24 f/4.5-5.6 EX DG on full frame cameras at the 12mm to 16mm range and it basically looks like really bad astigmatism. The DA 14mm f/2.8 you used for that image is quite acceptable. However, that may very well be due to the digital specific design of the DA series lens and the fact that it would be more inclined to project an image onto the sensor without the high incidence angle that legacy film lens designs tend to do.

JoepLX3 · 10-09-2010, 05:52 PM

Some where I also read reasonable stories on the Tamron 10 - 24 mm (but not at 10 mm...), probably better to put my "money" on a filter for the 18-55.

http://www.forumlogr.com/thread/yVWwwwSCEafn/Tamron-10-24-and-350D,-Infrared-revisited.html

siamthai · 01-13-2012, 08:46 AM

I'd like to try to do some IR photography but I don't know which of my lenses would be best suited for this. Anyone who have any advice on what lens I'd choose? I have the following lensens to choose from

Pentax Asahi Auto-Takumar 85mm f/1.8
Pentax SMC DA 18-55 f 3.5-5.6 WR
Pentax SMC-DA 50-200 f/4,0-5,6 ED WR
Pentax Super-Takumar 50mm f/1,4
Pentax SMC-DA 40/2.8 Limited
SMC Pentax DA 12-24mmF4ED AL (IF)
Sigma 50-500mm 1:4-6.3 APO EX DG

creampuff · 01-13-2012, 08:55 AM

Originally posted by siamthai

I'd like to try to do some IR photography but I don't know which of my lenses would be best suited for this. Anyone who have any advice on what lens I'd choose? I have the following lensens to choose from

Pentax Asahi Auto-Takumar 85mm f/1.8
Pentax SMC DA 18-55 f 3.5-5.6 WR
Pentax SMC-DA 50-200 f/4,0-5,6 ED WR
Pentax Super-Takumar 50mm f/1,4
Pentax SMC-DA 40/2.8 Limited
SMC Pentax DA 12-24mmF4ED AL (IF)
Sigma 50-500mm 1:4-6.3 APO EX DG

see this list
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/66895-ir-infra...tml#post671922

eddie1960 · 01-13-2012, 09:08 AM

the Pentax 12-24 looks pretty reasonable as well. last FEbruary Tim (Blackcloudbrew) shot a single in with his ir modded K100d

blackcloudbrew's Album: Single in February - PentaxForums.com

stanislav · 01-13-2012, 10:16 AM

I have just tested the IR photography and although I didn't give up on it completely it is not so high on my wishlist that I am ready to modify a DSLR to get a permanent IR camera. However I am trying to find some of the used Sony night-shot cameras (with switch to remove IR blocking filter) to by my entry point to IR photography.

Here are some of my observations with simple theoretical background:

1. Using IR filter with unmodified camera results in a very long exposure times, since the IR filter is used to block the visible light and the filter in front of the sensor is used to block IR light, resulting in very little light reaching the sensor.

2. Lenses are optimized for visible light so that the projection is sharpest in the visible part of spectrum. Since different wavelengths (read colours) have slightly different refraction index the colours (if not compensated) have slightly different focus points. The longer wavelengths bend less then the shorter in the same lens. In ordinary photografy the effect results in cromatic abberation (famous CA) whereas for IR the focus point should be slightly longer than for the visible light. CA can be addressed by the so called APO design where two or more lenses (or groups) are matched so that at least two wavelengths have same total refraction resulting in better resolution and smaller CA. This however does not have to be the case for IR since the wavelength differs more than those the lens was optimized for.

3. Softness and the border sharpness (or lack of it) should be more exagregated in IR compared to the visible light.

4. Hot spots tend to appear in cases when coating and the glas material reflect IR light from some surface thus leading to multiple reflections (similar to ghosting when taking photo of a bright light source).

5. Lenses with harder glass (LD - low dispersion lenses) have bigger refractive index so that the relative dispersion between different wavelengths should be smaller than with lenses with some plastic elements, which should result in sharper images.

6. It should be interresting to see some IR photos made with mirror lenses, since mirrors are purely reflective surfaces and should exhibit any CA, thus bending (or reflecting) all wavelengths at the same path. Actually more info about reflective vs. refractive lenses in generals can be found on many astronomy forums.

Well, I hope I didn't get too theoretical with my post. Cheers!

Nachodog · 01-13-2012, 11:54 AM

FWIW I found that the Sigma 10-20 is decent with IR.

siamthai · 01-13-2012, 01:16 PM

I think every input is welcome so keep writing about how you all find how good or bad different lenses are for IR photos (^_^)

**Digitalis** · 01-14-2012, 03:13 AM

The FA31mm f/1.8 and FA77mm f/1.8 Limited lenses are excellent for IR, the Pentax SMCP-K 50mm f/1.2 is also superb - because of the lens ultrawide f/1.2 aperture it is actually possible to focus the image in the viewfinder, though it does take your eyes a while to adjust to the darkness.

Originally posted by stanislav

5. Lenses with harder glass (LD - low dispersion lenses) have bigger refractive index so that the relative dispersion between different wavelengths should be smaller than with lenses with some plastic elements, which should result in sharper images.

I don't think so, the DA15mm f/4 Limited ASPH uses a hybird aspheric which is a glass lens bonded to a plastic aspherical lens - and the corner sharpness from the DA15mm f/4 limited isn't anything to write home about in the IR spectrum.

DA15mm f/4 flare with hoya R72 filter lens aperture @ f/4 - but the flare is still bad even at f/16.

RonHendriks1966 · 01-14-2012, 09:09 AM

I have a 49mm 720nm filter, but only used it a few times.

On DA21mm there is a hotspot.

creampuff · 01-14-2012, 05:38 PM

One thing I've noticed is there is definitely a difference if the lens tests were done with a standard camera with an an IR filter mounted in front of the lens or if the lenses were used on an IR-modded camera.

When used on an IR-modded camera, some lenses don't show obvious hotspotting when compared to lenses with an IR filter mounted in front. I can only surmise that either the shorter exposure times or the possible internal reflections from a front mounted IR filter are responsible for exacerbating the hotspots and internal reflections. One thing I do know is that results from an IR-modded camera that I'm using are a lot sharper and show better detail compared to when I used a normal IR filter on a conventional un-modded camera.

10-09-2010, 05:52 PM	#21
JoepLX3 Veteran Member Join Date: Aug 2010 Posts: 518	Some where I also read reasonable stories on the Tamron 10 - 24 mm (but not at 10 mm...), probably better to put my "money" on a filter for the 18-55. http://www.forumlogr.com/thread/yVWwwwSCEafn/Tamron-10-24-and-350D,-Infrared-revisited.html Last edited by JoepLX3; 10-09-2010 at 06:15 PM.

01-14-2012, 03:13 AM	#28
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	The FA31mm f/1.8 and FA77mm f/1.8 Limited lenses are excellent for IR, the Pentax SMCP-K 50mm f/1.2 is also superb - because of the lens ultrawide f/1.2 aperture it is actually possible to focus the image in the viewfinder, though it does take your eyes a while to adjust to the darkness. Originally posted by stanislav 5. Lenses with harder glass (LD - low dispersion lenses) have bigger refractive index so that the relative dispersion between different wavelengths should be smaller than with lenses with some plastic elements, which should result in sharper images. I don't think so, the DA15mm f/4 Limited ASPH uses a hybird aspheric which is a glass lens bonded to a plastic aspherical lens - and the corner sharpness from the DA15mm f/4 limited isn't anything to write home about in the IR spectrum. DA15mm f/4 flare with hoya R72 filter lens aperture @ f/4 - but the flare is still bad even at f/16. Last edited by Digitalis; 01-14-2012 at 03:21 AM.

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10-09-2010, 11:21 AM	#16
JoepLX3 Veteran Member Join Date: Aug 2010 Posts: 518	Originally posted by Digitalis avoid ultrawide lenses with infrared, because not only hot spots you will also likely encounter some serious smearing due to the fact that IR wavelengths aren't as easily bent as visible light wavelengths are. That's a pity, but understandably true... So filter needs to fit on my 18-55 mm II kit lens and some fast A prime. Are there hudge differences between IR filters and IR filters? - Which type / brand should I get (best bang for the buck)? I found a Dutch company that sell them (720 nm) NEW up 67 mm diameter from stock for less than 30 Euro's, including transport costs (they can also "make" bigger, but that takes time and at higher cost).

10-09-2010, 05:08 PM	#17
creampuff Veteran Member Join Date: May 2007 Location: Singapore Photos: Gallery Posts: 3,953	Originally posted by Digitalis avoid ultrawide lenses with infrared, because not only hot spots you will also likely encounter some serious smearing due to the fact that IR wavelengths aren't as easily bent as visible light wavelengths are. Do you have specific examples of what this "smearing" is all about? Can you elaborate what the "smearing" should look like? I myself have used an ultrawide like the DA 14mm with no issues and I know of other IR shooters using other brands with ultrawides who have not mentioned this issue. IR modded ist DL2 with DA 14mm f/2.8*

10-09-2010, 05:14 PM	#18
creampuff Veteran Member Join Date: May 2007 Location: Singapore Photos: Gallery Posts: 3,953	Originally posted by JoepLX3 That's a pity, but understandably true... So filter needs to fit on my 18-55 mm II kit lens and some fast A prime. Are there hudge differences between IR filters and IR filters? - Which type / brand should I get (best bang for the buck)? I found a Dutch company that sell them (720 nm) NEW up 67 mm diameter from stock for less than 30 Euro's, including transport costs (they can also "make" bigger, but that takes time and at higher cost). I have used external IR filters from Hoya, Cokin, B+W and generic made in China ones and even though they may all list a somewhat similar cutoff wavelength, they ALL show a different color/spectral rendition. Exposure times vary too.

10-09-2010, 05:34 PM	#19
JoepLX3 Veteran Member Join Date: Aug 2010 Posts: 518	Originally posted by creampuff I have used external IR filters from Hoya, Cokin, B+W and generic made in China ones and even though they may all list a somewhat similar cutoff wavelength, they ALL show a different color/spectral rendition. Exposure times vary too. The spectral bandwidth of those filters is typically pretty narrow and I don't see how one centered around 715 nm is better or worse than one centered around 730 nm. The effective width will determine the exposure time, but I (as you might expect) doubt impact on IQ...

10-09-2010, 05:42 PM	#20
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	Originally posted by creampuff Do you have specific examples of what this "smearing" is all about? Can you elaborate what the "smearing" should look like? I myself have used an ultrawide like the DA 14mm with no issues and I know of other IR shooters using other brands with ultrawides who have not mentioned this issue. IR modded ist DL2 with DA 14mm f/2.8* nice shot, I have seen this smearing with the sigma 12-24 f/4.5-5.6 EX DG on full frame cameras at the 12mm to 16mm range and it basically looks like really bad astigmatism. The DA 14mm f/2.8 you used for that image is quite acceptable. However, that may very well be due to the digital specific design of the DA series lens and the fact that it would be more inclined to project an image onto the sensor without the high incidence angle that legacy film lens designs tend to do.

01-13-2012, 08:46 AM	#22
siamthai Senior Member Join Date: Mar 2010 Location: Svealand Photos: Gallery \| Albums Posts: 172	I'd like to try to do some IR photography but I don't know which of my lenses would be best suited for this. Anyone who have any advice on what lens I'd choose? I have the following lensens to choose from Pentax Asahi Auto-Takumar 85mm f/1.8 Pentax SMC DA 18-55 f 3.5-5.6 WR Pentax SMC-DA 50-200 f/4,0-5,6 ED WR Pentax Super-Takumar 50mm f/1,4 Pentax SMC-DA 40/2.8 Limited SMC Pentax DA 12-24mmF4ED AL (IF) Sigma 50-500mm 1:4-6.3 APO EX DG

01-13-2012, 08:55 AM	#23
creampuff Veteran Member Join Date: May 2007 Location: Singapore Photos: Gallery Posts: 3,953	Originally posted by siamthai I'd like to try to do some IR photography but I don't know which of my lenses would be best suited for this. Anyone who have any advice on what lens I'd choose? I have the following lensens to choose from Pentax Asahi Auto-Takumar 85mm f/1.8 Pentax SMC DA 18-55 f 3.5-5.6 WR Pentax SMC-DA 50-200 f/4,0-5,6 ED WR Pentax Super-Takumar 50mm f/1,4 Pentax SMC-DA 40/2.8 Limited SMC Pentax DA 12-24mmF4ED AL (IF) Sigma 50-500mm 1:4-6.3 APO EX DG see this list https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/66895-ir-infra...tml#post671922

01-13-2012, 09:08 AM	#24
eddie1960 Veteran Member Join Date: Aug 2010 Location: Toronto Photos: Gallery \| Albums Posts: 13,666	the Pentax 12-24 looks pretty reasonable as well. last FEbruary Tim (Blackcloudbrew) shot a single in with his ir modded K100d blackcloudbrew's Album: Single in February - PentaxForums.com

01-13-2012, 10:16 AM	#25
stanislav Senior Member Join Date: Jan 2010 Location: Stockholm Photos: Albums Posts: 125	I have just tested the IR photography and although I didn't give up on it completely it is not so high on my wishlist that I am ready to modify a DSLR to get a permanent IR camera. However I am trying to find some of the used Sony night-shot cameras (with switch to remove IR blocking filter) to by my entry point to IR photography. Here are some of my observations with simple theoretical background: 1. Using IR filter with unmodified camera results in a very long exposure times, since the IR filter is used to block the visible light and the filter in front of the sensor is used to block IR light, resulting in very little light reaching the sensor. 2. Lenses are optimized for visible light so that the projection is sharpest in the visible part of spectrum. Since different wavelengths (read colours) have slightly different refraction index the colours (if not compensated) have slightly different focus points. The longer wavelengths bend less then the shorter in the same lens. In ordinary photografy the effect results in cromatic abberation (famous CA) whereas for IR the focus point should be slightly longer than for the visible light. CA can be addressed by the so called APO design where two or more lenses (or groups) are matched so that at least two wavelengths have same total refraction resulting in better resolution and smaller CA. This however does not have to be the case for IR since the wavelength differs more than those the lens was optimized for. 3. Softness and the border sharpness (or lack of it) should be more exagregated in IR compared to the visible light. 4. Hot spots tend to appear in cases when coating and the glas material reflect IR light from some surface thus leading to multiple reflections (similar to ghosting when taking photo of a bright light source). 5. Lenses with harder glass (LD - low dispersion lenses) have bigger refractive index so that the relative dispersion between different wavelengths should be smaller than with lenses with some plastic elements, which should result in sharper images. 6. It should be interresting to see some IR photos made with mirror lenses, since mirrors are purely reflective surfaces and should exhibit any CA, thus bending (or reflecting) all wavelengths at the same path. Actually more info about reflective vs. refractive lenses in generals can be found on many astronomy forums. Well, I hope I didn't get too theoretical with my post. Cheers!

01-13-2012, 11:54 AM	#26
Nachodog Veteran Member Join Date: Dec 2007 Location: Montreal, Qc Posts: 472	FWIW I found that the Sigma 10-20 is decent with IR.

01-13-2012, 01:16 PM	#27
siamthai Senior Member Join Date: Mar 2010 Location: Svealand Photos: Gallery \| Albums Posts: 172	I think every input is welcome so keep writing about how you all find how good or bad different lenses are for IR photos (^_^)

01-14-2012, 09:09 AM	#29
RonHendriks1966 Banned Join Date: Jan 2009 Photos: Gallery Posts: 9,675	I have a 49mm 720nm filter, but only used it a few times. On DA21mm there is a hotspot.

01-14-2012, 05:38 PM	#30
creampuff Veteran Member Join Date: May 2007 Location: Singapore Photos: Gallery Posts: 3,953	One thing I've noticed is there is definitely a difference if the lens tests were done with a standard camera with an an IR filter mounted in front of the lens or if the lenses were used on an IR-modded camera. When used on an IR-modded camera, some lenses don't show obvious hotspotting when compared to lenses with an IR filter mounted in front. I can only surmise that either the shorter exposure times or the possible internal reflections from a front mounted IR filter are responsible for exacerbating the hotspots and internal reflections. One thing I do know is that results from an IR-modded camera that I'm using are a lot sharper and show better detail compared to when I used a normal IR filter on a conventional un-modded camera.