IR filter reccomendations

[JustJazzie]

Good morning!

I hope all is well in your world today. I'm dropping in to ask for some direction in choosing a filter to give Infrared photography a go! We are going on a 3 week road trip this summer and I was thinking it would be a fun addition to bring along for when the lighting is harsh.

I am pretty sure I have decided to get a 62 mm so that it fits on my 28-105 (with macro mode). However, it only has an aperture of 3.5-4.5 Would it be better to put it on on my 50mm 1.8 or my 150mm 2.8 instead? I've never used any sort of filter that blocks light, so I am not sure how vital those stops of light will be, vs the versatility of a zoom lens.

That brings me of corse, to looking for brand recommendations. I am hoping that $75 or so would be reasonable since Its definitely a frivolous purchase right now.

Thanks for your thoughts!
Jazzie

 

[petrochemist]

Assuming your camera hasn't been converted to IR, you'll be limited to filters that only transmit 720nm and above. Filters used for colour IR are only suitable if the cameras hot mirror has been removed (boosting the cameras IR sensitivity).
With unmodified cameras the specific camera used will make a huge difference to the sensitivity with infra red.
My old DSLR has a weak hot mirror so is moderately sensitive to IR. With a 50mm /1.7 it's possible to hand hold shots with a 720nm filter. My newer DSLR goes to higher ISO, but has a much stronger hot mirror so that exposures take multiple seconds.

The easy way of judging your cameras IR sensitivity is to take a photograph of a TV remote while it's transmitting a signal (button held down). If the photo shows a strong glow from the remote your camera is seeing the IR. From what I've heard most Canon cameras have strong hot mirrors giving them very little IR sensitivity. Some older models (including Nikon's D70, Pentax's K100d and Inst*D) have fairly good response. Most modern models have poor enough response that a tripod will be essential.

Regarding specific filters the Hoya R72 is reckoned to be very good but it's much more expensive than the Chinese clones readily available on e-bay. I've only used cheap filters so can't tell if there's any significant difference but I've never had complaints on the results I've got.
For initial experiments I'd suggest a cheap filter (typically ~£20) in 720nm or 760nm flavour. You could use longer wavelengths but exposures will get significantly longer. Anything less than a 720 will transmit too much red so the IR will be swamped by visual light.

If the IR bug bites you will probably end up with a converted camera (or even several with different convertions). I have a 'full spectrum converted mirrorless camera which is IMO ideal. Using an EVF means that external filters can be fitted in front of the lens (limiting wavelengths to whatever passes the filter) yet I can still see to frame the image/focus etc. even if all visible light is blocked. DSLRs that are converted are usually dedicated to a specific filter, put directly in front of the sensor so that the user can see through the viewfinder.
With the converted camera 720nm+ shots by sunlight have similar exposures to normal visible shots on a standard camera.

 

[Derrel]

I would buy it for the larger-diameter lens. That way you'll have the ability to compose different types of images by zooming: wide-angle images with the Df, normal, and short tele images as well. For just a few dollars, you could buy the appropriate step ring from Fotodiox or some other vendor, and use the step ring to go from 62 down to 58mm or 52mm, depending on which Nikon 50mm lens you own. The basic idea is to buy a large specialty filter, one big enough for your largest filter size, and then use step rings to economically create a way to fit the filter to lenses of different filter diameters.

 

[astroNikon]

B+W has 4 IR type filters
I haven't researched other brands.
I have a 092 and 093 .. still trying to test them some more.

Love reading this site ... LifePixel Digital Infrared Photography IR Conversion, Modification & Scratched Sensor Repair

petrochemist & Tim are more of an expert of these things ...

092

• Used for Infrared Photography
• Blocks Visible Light Up To 650nm
• Passes 90% of Radiation From 730-2000nm

093

• Blocks Entire Visible Spectrum
• Filter Appears Opaque to the Eye
• Transmission Begins at 1% at 800nm
• Transmission Rises to 88% at 900nm

403
Not to be confused with UV-blocking filters that photographers normally refer to as “UV Filters”, this one passes UV A radiation (320 to 385 nm), but blocks visible light and looks pitch-black to our eyes. It is used with appropriately sensitized films in such applications as ultraviolet reflection photography in forensics or in materials research, but also as filters on UV-emitters for fluorescence photography. Depending on the illumination and on the film’s sensitization, its filter factor is in the range of 8 to 20.

486M
The B+W Filter 486 does not block by means of absorption, but by interference of the unwanted UV and IR radiation that is repeatedly reflected between these layers, affecting the wavelengths on both sides of the visible spectrum with a steep cut-off. It is used mainly on digital and video cameras with CCD sensors without an integrated IR protection filter, because the IR sensitivity of the CCD sensor would otherwise cause color changes and unsharpness. That unsharpness results from the chromatic aberration of the lenses that are only corrected for visible light. In the visible range, the transmission curve is very high and straight. This filter is completely clear and it requires no increase in exposure. Its filter factor is 1.

 

[snowbear]

One more consideration about IR is the focus is different from visible light. If your lens does not have the red dot you may not get sharp photos. I understand some conversions tune the lens and Af system.

 

[JustJazzie]

Assuming your camera hasn't been converted to IR, you'll be limited to filters that only transmit 720nm and above. Filters used for colour IR are only suitable if the cameras hot mirror has been removed (boosting the cameras IR sensitivity).
With unmodified cameras the specific camera used will make a huge difference to the sensitivity with infra red.
My old DSLR has a weak hot mirror so is moderately sensitive to IR. With a 50mm /1.7 it's possible to hand hold shots with a 720nm filter. My newer DSLR goes to higher ISO, but has a much stronger hot mirror so that exposures take multiple seconds.

The easy way of judging your cameras IR sensitivity is to take a photograph of a TV remote while it's transmitting a signal (button held down). If the photo shows a strong glow from the remote your camera is seeing the IR. From what I've heard most Canon cameras have strong hot mirrors giving them very little IR sensitivity. Some older models (including Nikon's D70, Pentax's K100d and Inst*D) have fairly good response. Most modern models have poor enough response that a tripod will be essential.

Regarding specific filters the Hoya R72 is reckoned to be very good but it's much more expensive than the Chinese clones readily available on e-bay. I've only used cheap filters so can't tell if there's any significant difference but I've never had complaints on the results I've got.
For initial experiments I'd suggest a cheap filter (typically ~£20) in 720nm or 760nm flavour. You could use longer wavelengths but exposures will get significantly longer. Anything less than a 720 will transmit too much red so the IR will be swamped by visual light.

If the IR bug bites you will probably end up with a converted camera (or even several with different convertions). I have a 'full spectrum converted mirrorless camera which is IMO ideal. Using an EVF means that external filters can be fitted in front of the lens (limiting wavelengths to whatever passes the filter) yet I can still see to frame the image/focus etc. even if all visible light is blocked. DSLRs that are converted are usually dedicated to a specific filter, put directly in front of the sensor so that the user can see through the viewfinder.
With the converted camera 720nm+ shots by sunlight have similar exposures to normal visible shots on a standard camera.

Thanks so much for the info! I am going to have to read it a few times to make sense of it all. I had no idea choosing a filter was so complicated! :Giggle: I will do this test on both my cameras and see which one might be better suited for the job!

I would buy it for the larger-diameter lens. That way you'll have the ability to compose different types of images by zooming: wide-angle images with the Df, normal, and short tele images as well. For just a few dollars, you could buy the appropriate step ring from Fotodiox or some other vendor, and use the step ring to go from 62 down to 58mm or 52mm, depending on which Nikon 50mm lens you own. The basic idea is to buy a large specialty filter, one big enough for your largest filter size, and then use step rings to economically create a way to fit the filter to lenses of different filter diameters.

THANK YOU THANK YOU THANK YOU! I had no idea step rings existed! I found quite a few good sets on amazon for super cheep. Ive avoided buying filters in general because of picking a size. These are wonderful to discover!

B+W has 4 IR type filters
I haven't researched other brands.
I have a 092 and 093 .. still trying to test them some more.

Love reading this site ... LifePixel Digital Infrared Photography IR Conversion, Modification & Scratched Sensor Repair

petrochemist & Tim are more of an expert of these things ...

092

• Used for Infrared Photography
• Blocks Visible Light Up To 650nm
• Passes 90% of Radiation From 730-2000nm

093

• Blocks Entire Visible Spectrum
• Filter Appears Opaque to the Eye
• Transmission Begins at 1% at 800nm
• Transmission Rises to 88% at 900nm

403
Not to be confused with UV-blocking filters that photographers normally refer to as “UV Filters”, this one passes UV A radiation (320 to 385 nm), but blocks visible light and looks pitch-black to our eyes. It is used with appropriately sensitized films in such applications as ultraviolet reflection photography in forensics or in materials research, but also as filters on UV-emitters for fluorescence photography. Depending on the illumination and on the film’s sensitization, its filter factor is in the range of 8 to 20.

486M
The B+W Filter 486 does not block by means of absorption, but by interference of the unwanted UV and IR radiation that is repeatedly reflected between these layers, affecting the wavelengths on both sides of the visible spectrum with a steep cut-off. It is used mainly on digital and video cameras with CCD sensors without an integrated IR protection filter, because the IR sensitivity of the CCD sensor would otherwise cause color changes and unsharpness. That unsharpness results from the chromatic aberration of the lenses that are only corrected for visible light. In the visible range, the transmission curve is very high and straight. This filter is completely clear and it requires no increase in exposure. Its filter factor is 1.

Again, lots of good information here. I appreciate you taking the time for such a thorough response! It has been super helpful!

One more consideration about IR is the focus is different from visible light. If your lens does not have the red dot you may not get sharp photos. I understand some conversions tune the lens and Af system.

The red dot? I am not sure what that means to be honest....on most of the tutorials I saw, you focus with the filter off and then apply the filter. Would this avoid the need for my red dot?

 

[astroNikon]

FYI, most of my filters are 77mm which fit my 18-35, 80-200 and a few other lenses.
I use StepUp rings on my smaller diameter lenses - 72, 67, 52mm to 77mm
I also have StepDown rings on my larger lenses such as 96mm to 77mm.

 

[JustJazzie]

FYI, most of my filters are 77mm which fit my 18-35, 80-200 and a few other lenses.
I use StepUp rings on my smaller diameter lenses - 72, 67, 52mm to 77mm
I also have StepDown rings on my larger lenses such as 96mm to 77mm.

I get the step down rings, but don't step up rings cause optical issues from the border?

 

[astroNikon]

The Step Down rings, which take a larger diameter such as 96mm and steps it DOWN to, in thus example 77mm does make the image circle smaller.

So if you have an image that normally fills the frame, it will get chopped.
But I only use those when I'm photographing the sun, which is in the middle of the view anyways. It's a lot cheaper than buying filters at 96mm in size. As filters get bigger their price really jumps up.

 

[petrochemist]

I get the step down rings, but don't step up rings cause optical issues from the border?

Step down are for fitting a filters smaller than your lenses threads. This can cause vignetting issues, but doesn't always. I've been lucky when I used 49mm filters on 52mm lenses & 25mm filters on a lens with 37mm lens threads (the lenses front element being quite a bit smaller than the thread in this case), and rarely seen any noticeable effect.

The only issues with step up ring are the cost of the bigger filters & likely difficulty with fitting lens hoods.

 

[snowbear]

The focal point for IR light is apparently shorter than that for visible light (I don't know or understand the physics) so the lens focus has to be compensated a bit. Older lenses have an red dot or a red letter "R" to indicated the IR focus point.

None of the kit lenses I have seen have this indicator, but my AF-D 24 and 50 primes have them (though the dot is now white). I don't know about the mid and top end zooms. Maybe Nikon has not bothered with them on the DX digital lenses.

 

[petrochemist]

The focal point for IR light is apparently shorter than that for visible light (I don't know or understand the physics) so the lens focus has to be compensated a bit. Older lenses have an red dot or a red letter "R" to indicated the IR focus point.

None of the kit lenses I have seen have this indicator, but my AF-D 24 and 50 primes have them (though the dot is now white). I don't know about the mid and top end zooms. Maybe Nikon has not bothered with them on the DX digital lenses.

Most older MF primes have some sort of mark for IR, a few one touch zooms have a line that shows the position for each focal length (it does change). I don't think I've seen it on any modern lens. From the little of the physics I understand it can be shorter or longer than the visible mark, though shorter is certainly more common.
Lens designers general are concerned with the visible wavelengths, in some cases Apochromatic lenses (corrected for 3 colours) can have a much bigger difference for IR than achromatic lenses which are only corrected for two colours. There are a few ultra apochromatic lenses that have been designed to focus UV, visible & IR at the same point. unfortunately they are both rare & expensive.