Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?

Started 3 months ago | Questions
nkistrup
nkistrup Senior Member • Posts: 2,497
Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?

Scoured the Internet, and cannot find anything about infrared photography with regards to sensor size.

Does infrared photography benefit more than visible light photography, by using a camera with a larger sensor?  (e.g. Full Frame vs. 4/3 micro)

My guess is that larger sensors let in more light, therefore they are better for infrared, but that advantage is no more than would be seen when shooting in visible light.  (IOW, big sensor better regardless of what part of the E.M.S. your are shooting in.)

Niels

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ANSWER:
saltydogstudios
saltydogstudios Senior Member • Posts: 2,218
Re: Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?
1

nkistrup wrote:

Scoured the Internet, and cannot find anything about infrared photography with regards to sensor size.

Does infrared photography benefit more than visible light photography, by using a camera with a larger sensor? (e.g. Full Frame vs. 4/3 micro)

My guess is that larger sensors let in more light, therefore they are better for infrared, but that advantage is no more than would be seen when shooting in visible light. (IOW, big sensor better regardless of what part of the E.M.S. your are shooting in.)

Niels

You may get a better response in the "science & tech" forum but my guess would be no benefit.

Longer wavelengths would benefit from a deeper sensor (perhaps) but the area does not affect the depth.

I own a micro four thirds full spectrum converted camera & enjoy it - I add a low-pass filter if I want to use it for Infrared.

You should also look into Foveon cameras, which have a removable hot mirror (blocks IR/UV light) and a dedicated long wavelength portion of the sensor.

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Mark Scott Abeln
Mark Scott Abeln Forum Pro • Posts: 16,201
Re: Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?
1

nkistrup wrote:

Does infrared photography benefit more than visible light photography, by using a camera with a larger sensor? (e.g. Full Frame vs. 4/3 micro)

I would think so.

But I think it would be more important to get a camera that is known to be easy to work with infrared, for example, allows you to directly see focus adjustment.

Were I to do more infrared photography, I'd likely get a well-recommended, pre-converted model.

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JimH123 Senior Member • Posts: 2,723
Re: Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?

saltydogstudios wrote:

nkistrup wrote:

Scoured the Internet, and cannot find anything about infrared photography with regards to sensor size.

Does infrared photography benefit more than visible light photography, by using a camera with a larger sensor? (e.g. Full Frame vs. 4/3 micro)

My guess is that larger sensors let in more light, therefore they are better for infrared, but that advantage is no more than would be seen when shooting in visible light. (IOW, big sensor better regardless of what part of the E.M.S. your are shooting in.)

Niels

You may get a better response in the "science & tech" forum but my guess would be no benefit.

Longer wavelengths would benefit from a deeper sensor (perhaps) but the area does not affect the depth.

I own a micro four thirds full spectrum converted camera & enjoy it - I add a low-pass filter if I want to use it for Infrared.

You should also look into Foveon cameras, which have a removable hot mirror (blocks IR/UV light) and a dedicated long wavelength portion of the sensor.

Not sure that this question can be directly answered with yes or no. A lot depends upon the camera itself. Some cameras are far better at using high ISO values and generate less noise than other cameras, this has to be taken into account. Larger sensors as a rule, then to generate less noise at comparable ISOs than smaller sensors. But some cameras, even with smaller sensors can out perform some older generation larger sensor cameras.

I have two cameras converted to full spectrum IR. First is an older Sony A55. Second is an Olympus EM5ii. Some comparisons. The Sony A55 seems to generate less noise, but it doesn't do so well with autofocus and I am better off using manual focus.

The EM5ii is mirrorless, and focus with all my lenses is no issue at all. But with longer exposures, it generates a lot of hot pixels that I don't see on the A55.

For instance, here is a 30 sec shot of the star Muscida at ISO 3200 with a 630nm filter using a 500mm FL lens. Yes, there was tracking. And then the conversion to B&W and also treatment with Topaz Denoise AI, Clear Mode.

Keep in mind that when doing IR, you are going to be using only 25% of the pixels - only the Red filtered pixels.

If I were to try this same shot with the EM5ii, there would be more noise and there would be hot pixels.

Sony A55, 500mm lens, 30 sec exposure, ISO 3200

Above image converted to B&W and treated with Topaz Denoise AI Clear

Now, I have another camera converted to full spectrum IR, but it has one more thing going for it, and that is that it has had the CFA scraped off so that it is a mono sensor now. So now with an IR filter, all pixels participate. This is a Sony A6300. And what a difference this makes. Noise is lower, plus no demosaicing is needed. The results are superior.

Here is one taken with the A6300 with a 360mm FL telescope and a UV-IR cut filter so that it was using visible light. It is the galaxy m101. This was a stack of 12 images of 15 sec each and ISO 1260.  With no colored filters over the pixels, the sensor is more sensitive.

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a_c_skinner Forum Pro • Posts: 10,410
Re: Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?
2

Practically I'd find out which of the lenses you've got work well in IR and if they do you've chosen your system.

Few people settle to IR as their main output so I'd also look at affordability, body cost and re-use of existing lens outfit.

I suspect sensor size comes down to the same questions as visible light.

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Richard B99 Senior Member • Posts: 2,989
Re: Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?
2

nkistrup wrote:

Scoured the Internet, and cannot find anything about infrared photography with regards to sensor size.

Does infrared photography benefit more than visible light photography, by using a camera with a larger sensor? (e.g. Full Frame vs. 4/3 micro)

My guess is that larger sensors let in more light, therefore they are better for infrared, but that advantage is no more than would be seen when shooting in visible light. (IOW, big sensor better regardless of what part of the E.M.S. your are shooting in.)

Niels

In broad terms, it’s going to be the same as for visible light with regard to sensor size.  Larger is better.  But whether that proportionately more or less is very hard to say or measure.  I chose the middle path with a Nikon DX sensor full spectrum conversion.

Richard B99 Senior Member • Posts: 2,989
Re: Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?
1

JimH123 wrote

Keep in mind that when doing IR, you are going to be using only 25% of the pixels - only the Red filtered pixels..

There are a couple of bits of weirdness that creep in here.  First, it’s absolutely the case that the red pixels will do the ‘ heavy lifting’ for IR.  However, we simply don’t know far the green and blue filtration extends into the IR wavelengths.  So there may be a contribution from those pixels too.  Additionally, the demosaicing process will still interpolate across these other pixels (with their filtered signals).  So, it’s really tough to be certain precisely what’s going on.  Nevertheless, It’s very fair to say, IR is going to be working with much less data and the images end up being ‘rougher’ in the end compared with visible/full spectrum.

nkistrup
OP nkistrup Senior Member • Posts: 2,497
Daytime IR shooting

JimH123 wrote:

saltydogstudios wrote:

nkistrup wrote:

Scoured the Internet, and cannot find anything about infrared photography with regards to sensor size.

Does infrared photography benefit more than visible light photography, by using a camera with a larger sensor? (e.g. Full Frame vs. 4/3 micro)

My guess is that larger sensors let in more light, therefore they are better for infrared, but that advantage is no more than would be seen when shooting in visible light. (IOW, big sensor better regardless of what part of the E.M.S. your are shooting in.)

Niels

You may get a better response in the "science & tech" forum but my guess would be no benefit.

Longer wavelengths would benefit from a deeper sensor (perhaps) but the area does not affect the depth.

I own a micro four thirds full spectrum converted camera & enjoy it - I add a low-pass filter if I want to use it for Infrared.

You should also look into Foveon cameras, which have a removable hot mirror (blocks IR/UV light) and a dedicated long wavelength portion of the sensor.

Not sure that this question can be directly answered with yes or no. A lot depends upon the camera itself. Some cameras are far better at using high ISO values and generate less noise than other cameras, this has to be taken into account. Larger sensors as a rule, then to generate less noise at comparable ISOs than smaller sensors. But some cameras, even with smaller sensors can out perform some older generation larger sensor cameras.

I have two cameras converted to full spectrum IR. First is an older Sony A55. Second is an Olympus EM5ii. Some comparisons. The Sony A55 seems to generate less noise, but it doesn't do so well with autofocus and I am better off using manual focus.

The EM5ii is mirrorless, and focus with all my lenses is no issue at all. But with longer exposures, it generates a lot of hot pixels that I don't see on the A55.

For instance, here is a 30 sec shot of the star Muscida at ISO 3200 with a 630nm filter using a 500mm FL lens. Yes, there was tracking. And then the conversion to B&W and also treatment with Topaz Denoise AI, Clear Mode.

Keep in mind that when doing IR, you are going to be using only 25% of the pixels - only the Red filtered pixels.

If I were to try this same shot with the EM5ii, there would be more noise and there would be hot pixels.

Sony A55, 500mm lens, 30 sec exposure, ISO 3200

Above image converted to B&W and treated with Topaz Denoise AI Clear

Now, I have another camera converted to full spectrum IR, but it has one more thing going for it, and that is that it has had the CFA scraped off so that it is a mono sensor now. So now with an IR filter, all pixels participate. This is a Sony A6300. And what a difference this makes. Noise is lower, plus no demosaicing is needed. The results are superior.

Here is one taken with the A6300 with a 360mm FL telescope and a UV-IR cut filter so that it was using visible light. It is the galaxy m101. This was a stack of 12 images of 15 sec each and ISO 1260. With no colored filters over the pixels, the sensor is more sensitive.

Hi Jim,

Wasn't even thinking astrophotography.  Made 2 forays into infrared in the past, and this is more my style: https://graphitepaddle.smugmug.com/Infrared-photography/Morris-Arboretum/

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nkistrup
OP nkistrup Senior Member • Posts: 2,497
Re: Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?

Mark Scott Abeln wrote:

nkistrup wrote:

Does infrared photography benefit more than visible light photography, by using a camera with a larger sensor? (e.g. Full Frame vs. 4/3 micro)

I would think so.

But I think it would be more important to get a camera that is known to be easy to work with infrared, for example, allows you to directly see focus adjustment.

Were I to do more infrared photography, I'd likely get a well-recommended, pre-converted model.

Hi Mark,

That's why I'm dead set on mirrorless.  (Renting an 850nm converted Nikon D810, and there no comparison to my now deceased full spectrum Sony a6300; you have to have a good EVF, since the sun will be at your back of the most of the time.)

That aside, more expensive cameras have more features, and those tend to be the larger sensor variety.  Sounds like my gut instinct to avoid 4/3 & go FF, was the right one.

Niels

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nkistrup
OP nkistrup Senior Member • Posts: 2,497
Re: Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?

a_c_skinner wrote:

Practically I'd find out which of the lenses you've got work well in IR and if they do you've chosen your system.

Few people settle to IR as their main output so I'd also look at affordability, body cost and re-use of existing lens outfit.

I suspect sensor size comes down to the same questions as visible light.

Preaching to the choir Andrew about lenses,

Been down this road with a full spectrum Sony a6300 that died in August.  Most lenses that I tried have IR hot spots, so realize how important this is.  And while you can rent lenses, there are few options for converted camera bodies.

Sony E mount: Know that the Tamron 70-180 & 28-200 play very nice w. IR.  And the 17-28 & 28-75 probably do.

Still need to test my Nikon 17-55 f2.8, to see if Nikon APS-C mirrorless is an option.  But to your point, if good IR lenses are not available, who cares about the camera body.  Trying to narrow the search parameters.

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nkistrup
OP nkistrup Senior Member • Posts: 2,497
Re: Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?

Richard B99 wrote:

nkistrup wrote:

Scoured the Internet, and cannot find anything about infrared photography with regards to sensor size.

Does infrared photography benefit more than visible light photography, by using a camera with a larger sensor? (e.g. Full Frame vs. 4/3 micro)

My guess is that larger sensors let in more light, therefore they are better for infrared, but that advantage is no more than would be seen when shooting in visible light. (IOW, big sensor better regardless of what part of the E.M.S. your are shooting in.)

Niels

In broad terms, it’s going to be the same as for visible light with regard to sensor size. Larger is better. But whether that proportionately more or less is very hard to say or measure. I chose the middle path with a Nikon DX sensor full spectrum conversion.

Before posting the question, past experience using both APS-C & FF suggests going w. the later for IR.  Larger sensors are just better.

If my Nikon 17-55 f2.8 turns out to be an IR dud, will go Sony FF since I now certain Tamron lenses are IR friendly.

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JimH123 Senior Member • Posts: 2,723
Re: Daytime IR shooting

nkistrup wrote:

JimH123 wrote:

saltydogstudios wrote:

nkistrup wrote:

Scoured the Internet, and cannot find anything about infrared photography with regards to sensor size.

Does infrared photography benefit more than visible light photography, by using a camera with a larger sensor? (e.g. Full Frame vs. 4/3 micro)

My guess is that larger sensors let in more light, therefore they are better for infrared, but that advantage is no more than would be seen when shooting in visible light. (IOW, big sensor better regardless of what part of the E.M.S. your are shooting in.)

Niels

You may get a better response in the "science & tech" forum but my guess would be no benefit.

Longer wavelengths would benefit from a deeper sensor (perhaps) but the area does not affect the depth.

I own a micro four thirds full spectrum converted camera & enjoy it - I add a low-pass filter if I want to use it for Infrared.

You should also look into Foveon cameras, which have a removable hot mirror (blocks IR/UV light) and a dedicated long wavelength portion of the sensor.

Not sure that this question can be directly answered with yes or no. A lot depends upon the camera itself. Some cameras are far better at using high ISO values and generate less noise than other cameras, this has to be taken into account. Larger sensors as a rule, then to generate less noise at comparable ISOs than smaller sensors. But some cameras, even with smaller sensors can out perform some older generation larger sensor cameras.

I have two cameras converted to full spectrum IR. First is an older Sony A55. Second is an Olympus EM5ii. Some comparisons. The Sony A55 seems to generate less noise, but it doesn't do so well with autofocus and I am better off using manual focus.

The EM5ii is mirrorless, and focus with all my lenses is no issue at all. But with longer exposures, it generates a lot of hot pixels that I don't see on the A55.

For instance, here is a 30 sec shot of the star Muscida at ISO 3200 with a 630nm filter using a 500mm FL lens. Yes, there was tracking. And then the conversion to B&W and also treatment with Topaz Denoise AI, Clear Mode.

Keep in mind that when doing IR, you are going to be using only 25% of the pixels - only the Red filtered pixels.

If I were to try this same shot with the EM5ii, there would be more noise and there would be hot pixels.

Sony A55, 500mm lens, 30 sec exposure, ISO 3200

Above image converted to B&W and treated with Topaz Denoise AI Clear

Now, I have another camera converted to full spectrum IR, but it has one more thing going for it, and that is that it has had the CFA scraped off so that it is a mono sensor now. So now with an IR filter, all pixels participate. This is a Sony A6300. And what a difference this makes. Noise is lower, plus no demosaicing is needed. The results are superior.

Here is one taken with the A6300 with a 360mm FL telescope and a UV-IR cut filter so that it was using visible light. It is the galaxy m101. This was a stack of 12 images of 15 sec each and ISO 1260. With no colored filters over the pixels, the sensor is more sensitive.

Hi Jim,

Wasn't even thinking astrophotography. Made 2 forays into infrared in the past, and this is more my style: https://graphitepaddle.smugmug.com/Infrared-photography/Morris-Arboretum/

I enjoy that style too. I like B&W IR images and not so much the pseudo coloring images. The astrophotography images are useful in that it shows the results in a difficult situation. Stars, as point sources of light, bring out the weakness of the lens, the sensor, the demosaicing, etc. If it can do good with these, it can do good with everything else.  Stars easily show off things like CA, Astigmatism, Coma Distortion and all sorts of other distortion plus the amount of noise that has been generated.

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ken_in_nh Senior Member • Posts: 1,098
Re: Daytime IR shooting

WRT IR shooting, much depends on what you shoot and under what conditions.  Unless you're doing technical or scientific shooting, you'll be shooting landscapes no doubt.  why?  Because that's where the dramatic IR effects are.  Not with portraits.  Not with sports.  If you just want color shift effects, you hardly need an IR converted camera!

This means you won't be pushing ISO speeds and you won't need particularly fast shutter speeds.  Any advantage of FF fades away at this point, unless you want FF in order to spend more money and impress your friends with big lenses and big cameras.

Keep in mind too that part of the classic IR film look was the grain.  (Yes, I've been shooting IR since the late 1960s!).  I suspect that any image noise you might get will not detract from an image.

As others have suggested, lens choice is more critical than camera choice.  Fortunately, there's enough information online to guide you through this problem.

nkistrup
OP nkistrup Senior Member • Posts: 2,497
Re: Daytime IR shooting

ken_in_nh wrote:

If you just want color shift effects, you hardly need an IR converted camera!

Can you explain this?

This means you won't be pushing ISO speeds and you won't need particularly fast shutter speeds. Any advantage of FF fades away at this point, unless you want FF in order to spend more money and impress your friends with big lenses and big cameras.

Only time I'll be increasing ISO, is to freeze action of water, vegetation, etc.   So point taken about one of the advantages of FF (i.e. better handling of high ISO values).  But you don't think it has any other advantages for IR?  (e.g. better image quality from letting in more light)

Keep in mind too that part of the classic IR film look was the grain. (Yes, I've been shooting IR since the late 1960s!). I suspect that any image noise you might get will not detract from an image.

Not so sure about that.  But it might be something to experiment with.

As others have suggested, lens choice is more critical than camera choice. Fortunately, there's enough information online to guide you through this problem.

Actually, the online sources are suspect.  The 4 Nikon F mount lenses that I considered important toward converting a Nikon Z camera to IR, were rated highly ... but I found otherwise.

With that said, I know of at least 2 well-behaved Tamron lenses, for the Sony FE mount.  And there are 2 other Tamron lenses that probably play nice with infrared.  So I'm thinking Sony, but FF.

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dmanthree
dmanthree Veteran Member • Posts: 8,790
Re: Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?

a_c_skinner wrote:

Practically I'd find out which of the lenses you've got work well in IR and if they do you've chosen your system.

Few people settle to IR as their main output so I'd also look at affordability, body cost and re-use of existing lens outfit.

I suspect sensor size comes down to the same questions as visible light.

Ditto on the lenses. But I'm wondering if my Sony RX10 IV will be a good candidate for IR conversion. Is that lens suitable?

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JimH123 Senior Member • Posts: 2,723
Re: Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?
1

dmanthree wrote:

a_c_skinner wrote:

Practically I'd find out which of the lenses you've got work well in IR and if they do you've chosen your system.

Few people settle to IR as their main output so I'd also look at affordability, body cost and re-use of existing lens outfit.

I suspect sensor size comes down to the same questions as visible light.

Ditto on the lenses. But I'm wondering if my Sony RX10 IV will be a good candidate for IR conversion. Is that lens suitable?

Kolarivision advertises conversion of this camera.  Contact them and see what they have to say about it.

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robgendreau Veteran Member • Posts: 7,812
Re: Infrared Conversion: 4/3 micro vs. Crop vs. FF sensor?

I'm getting a Canon RP converted as we speak. We'll see how full spectrum is on it; I've used Olys before and they work great, as do most of the lenses at most apertures.

Had a K-01 too and it was fine, although the lack of a VF was a hassle in bright noon light.

I'd guess that in full spectrum you'd get some of the same advantages with FF. So more light hence less noise all other things being equal. But 99% of my images are landscapes and bright midday light is often the best for that anyway; it's not like I'm shooting in dark evening street scenes much with an 850nm on it.

Other factors might be more important, like the lenses as already discussed. I figured out that the Pentax to RF adapter I got can be hacked to include a glued-in 46mm filter ring, so I can drop in filters for my wide angles that don't accept lenses filters. Kinda nice. Sometimes it's  little details like that which will tip the balance since so many cameras are good candidates these days for conversion.

nkistrup
OP nkistrup Senior Member • Posts: 2,497
Hot spots: Function of DoF? Or fstop value?

Only occurred to me this morning.  For a given lens on a 1.5x crop, it has same DoF as a full frame camera, a full stop higher.  Example: f5.6 on a 1.5x crop is the same DoF as f8 on full frame.  So if a hot spot shows at f16 on full frame testing, it will show up at f11 on a 1.5 crop?

Or are hot spots a function of the aperture blades of the lens, which are constant for a given fstop value?  Curious.

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robgendreau Veteran Member • Posts: 7,812
Re: Hot spots: Function of DoF? Or fstop value?
3

nkistrup wrote:

Only occurred to me this morning. For a given lens on a 1.5x crop, it has same DoF as a full frame camera, a full stop higher. Example: f5.6 on a 1.5x crop is the same DoF as f8 on full frame. So if a hot spot shows at f16 on full frame testing, it will show up at f11 on a 1.5 crop?

Or are hot spots a function of the aperture blades of the lens, which are constant for a given fstop value? Curious.

Tough question. See https://kolarivision.com/the-science-of-infrared-hotspots/ eg.

nkistrup
OP nkistrup Senior Member • Posts: 2,497
Re: Hot spots: Function of DoF? Or fstop value?

robgendreau wrote:

nkistrup wrote:

Only occurred to me this morning. For a given lens on a 1.5x crop, it has same DoF as a full frame camera, a full stop higher. Example: f5.6 on a 1.5x crop is the same DoF as f8 on full frame. So if a hot spot shows at f16 on full frame testing, it will show up at f11 on a 1.5 crop?

Or are hot spots a function of the aperture blades of the lens, which are constant for a given fstop value? Curious.

Tough question. See https://kolarivision.com/the-science-of-infrared-hotspots/ eg.

Thanks robgendreau!  Didn't answer my question, but learned three things:

  1. Sensor DO MAKE a difference.  Really big take away, since I always ASSUMED that hot spots were strictly a lens issue.
  2. Testing is dependent on the focus point.
  3. Gave my Zeiss 50mm f2 a failing grade, when I tested it for hot spots.  Wondering if my test procedures were suspect?
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