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

Started 3 months ago | Questions thread
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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