Full-Spectrum for everyone

MJKoski · 09-18-2020, 04:13 AM - **3 Likes**

Sigma Foveon cameras have long been available with user removable IR hot-mirror component. It is very easy to operate and also works as dust spot eliminator when installed (dust located on a filter away from sensor stack does not pop up easily in the photos).

This would enable easy IR and even UV photography for everyone provided lenses are good for such task.

Pentax could do better than Sigma easily - just provide various IR cutoff filters which can be installed in place of the standard hot-mirror filter. These guarantee a lot better flare resistance compared to screw-on filters.

Full-spectrum or at least two-spectrum (VIS-IR) for everyone!

**BigMackCam** · 09-18-2020, 02:16 PM

That's actually a pretty awesome idea, and - compared to other areas of camera development - arguably not that difficult to achieve. It's mostly design of the mirror box internals and the swappable filters, with perhaps a little software to leverage them to best advantage.

MJKoski · 09-19-2020, 03:38 AM - **1 Like**

Ya! And it would give Pentax yet another unique feature to make K-1 MK3 better than any unmodified FF MILC out there. Same goes for APS-C.

**travelswsage** · 09-19-2020, 05:17 AM

I agree -- fantastic idea. I'd be a buyer. If we could also get support for focus stacking I'd be in seventh heaven ....

**Serkevan** · 09-25-2020, 01:02 AM

Just noticed the thread... this idea is certainly cool! Would it be -in principle, at least- possible to swap the standard filter with something astro-minded as well (Ha was it?). As far as I know those are inserted under the mirror but that of course is slightly more cumbersome, and on an unmodified camera the end result is still affected...

I probably wouldn't use it too often, but anything that makes Pentax the option for outdoorspeople is a good feature to have IMO

.

Wasp · 09-25-2020, 02:07 AM

I like the idea but can consumers be trusted not to make a mess of it? Changing a focusing screen is kinda tricky. Changing a filter on the sensor would be even trickier. If you get it wrong you can scratch and/or ruin your sensor.

**BigMackCam** · 09-25-2020, 02:14 AM

Originally posted by Wasp

I like the idea but can consumers be trusted not to make a mess of it? Changing a focusing screen is kinda tricky. Changing a filter on the sensor would be even trickier. If you get it wrong you can scratch and/or ruin your sensor.

On the Sigma cameras, if I remember correctly the filter isn't attached to the sensor module but sits just in front of it, held in place by the surrounding mirror box...

MJKoski · 09-25-2020, 09:52 AM

Yes, I have Quattro SD and the filter is right before the lens mount. It can be clipped off and lifted out easily with two fingers or a pair of pliers.

There is already clip-on filter available which can be installed between the mirror and the lens. Actually at least two products exist - Pro Planet and XTC. Former is more for astro and latter for general IR shooting.

**Photos-by-Chas** · 12-09-2020, 06:31 PM

Originally posted by Wasp

I like the idea but can consumers be trusted not to make a mess of it? Changing a focusing screen is kinda tricky. Changing a filter on the sensor would be even trickier. If you get it wrong you can scratch and/or ruin your sensor.

That would be a definite problem unless one knew exactly what they were doing. A new sensor could be a bit expensive.

MJKoski · 12-11-2020, 07:13 AM - **1 Like**

Well, if done the same way as Sigma has done, there is no risk of ruining the sensor. And, as the Sigma bodies come with IR-cut filter installed as default, there is no need for the user to ever touch the clip-filter system if they don't want to shoot IR.

zapp · 06-12-2021, 03:32 AM

Did anyone notice the difference between the Sigma lens mount an a mirrorless camera compared to a Pentax DSLR? Sorry, won’t work well and the sensor still needs a cover glass.

Philoslothical · 07-11-2021, 06:51 PM - **1 Like**

Originally posted by BigMackCam

It's mostly design of the mirror box internals and the swappable filters, with perhaps a little software to leverage them to best advantage.

If somebody wanted to really engineer something like this, a set of swappable filters could be integrated and stored in the camera, just a setting away from being slid into place. You could choose among the popular wavelength filters in the field this way. A setting for no filter would be reasonable, too, for times when you want to use a filter on the lens or elsewhere in your optical stack, such as with filters for microscopes. Actually, the way some microscopes integrate filters is close to what I'm imagining, but with microscopes they're implemented on a much larger scale and generally moved by hand. The filters for a sensor would be tiny things by comparison, but they'd work much the same way, sliding in and out of the optical path. I think such a camera would be very nice and worth the additional expense to some people.

09-18-2020, 04:13 AM - 3 Likes	#1
MJKoski Veteran Member Join Date: Aug 2016 Posts: 1,784	Full-Spectrum for everyone Sigma Foveon cameras have long been available with user removable IR hot-mirror component. It is very easy to operate and also works as dust spot eliminator when installed (dust located on a filter away from sensor stack does not pop up easily in the photos). This would enable easy IR and even UV photography for everyone provided lenses are good for such task. Pentax could do better than Sigma easily - just provide various IR cutoff filters which can be installed in place of the standard hot-mirror filter. These guarantee a lot better flare resistance compared to screw-on filters. Full-spectrum or at least two-spectrum (VIS-IR) for everyone!

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09-18-2020, 02:16 PM	#2
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,706	That's actually a pretty awesome idea, and - compared to other areas of camera development - arguably not that difficult to achieve. It's mostly design of the mirror box internals and the swappable filters, with perhaps a little software to leverage them to best advantage.

09-19-2020, 03:38 AM - 1 Like	#3
MJKoski Veteran Member Join Date: Aug 2016 Posts: 1,784 Original Poster	Ya! And it would give Pentax yet another unique feature to make K-1 MK3 better than any unmodified FF MILC out there. Same goes for APS-C.

09-19-2020, 05:17 AM	#4
travelswsage Site Supporter Join Date: Jun 2016 Posts: 385	I agree -- fantastic idea. I'd be a buyer. If we could also get support for focus stacking I'd be in seventh heaven ....

09-25-2020, 01:02 AM	#5
Serkevan Site Supporter Join Date: May 2019 Photos: Albums Posts: 5,976	Just noticed the thread... this idea is certainly cool! Would it be -in principle, at least- possible to swap the standard filter with something astro-minded as well (Ha was it?). As far as I know those are inserted under the mirror but that of course is slightly more cumbersome, and on an unmodified camera the end result is still affected... I probably wouldn't use it too often, but anything that makes Pentax the option for outdoorspeople is a good feature to have IMO .

09-25-2020, 02:07 AM	#6
Wasp Pentaxian Join Date: Mar 2017 Location: Pretoria Photos: Gallery Posts: 4,663	I like the idea but can consumers be trusted not to make a mess of it? Changing a focusing screen is kinda tricky. Changing a filter on the sensor would be even trickier. If you get it wrong you can scratch and/or ruin your sensor.

09-25-2020, 02:14 AM	#7
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,706	Originally posted by Wasp I like the idea but can consumers be trusted not to make a mess of it? Changing a focusing screen is kinda tricky. Changing a filter on the sensor would be even trickier. If you get it wrong you can scratch and/or ruin your sensor. On the Sigma cameras, if I remember correctly the filter isn't attached to the sensor module but sits just in front of it, held in place by the surrounding mirror box...

09-25-2020, 09:52 AM	#8
MJKoski Veteran Member Join Date: Aug 2016 Posts: 1,784 Original Poster	Yes, I have Quattro SD and the filter is right before the lens mount. It can be clipped off and lifted out easily with two fingers or a pair of pliers. There is already clip-on filter available which can be installed between the mirror and the lens. Actually at least two products exist - Pro Planet and XTC. Former is more for astro and latter for general IR shooting.

12-09-2020, 06:31 PM	#9
Photos-by-Chas Site Supporter Join Date: Jul 2012 Location: Northwest Pennsylvania, USA Photos: Gallery \| Albums Posts: 1,318	Originally posted by Wasp I like the idea but can consumers be trusted not to make a mess of it? Changing a focusing screen is kinda tricky. Changing a filter on the sensor would be even trickier. If you get it wrong you can scratch and/or ruin your sensor. That would be a definite problem unless one knew exactly what they were doing. A new sensor could be a bit expensive.

12-11-2020, 07:13 AM - 1 Like	#10
MJKoski Veteran Member Join Date: Aug 2016 Posts: 1,784 Original Poster	Well, if done the same way as Sigma has done, there is no risk of ruining the sensor. And, as the Sigma bodies come with IR-cut filter installed as default, there is no need for the user to ever touch the clip-filter system if they don't want to shoot IR.

06-12-2021, 03:32 AM	#11
zapp Pentaxian Join Date: Jul 2011 Posts: 2,389	Did anyone notice the difference between the Sigma lens mount an a mirrorless camera compared to a Pentax DSLR? Sorry, won’t work well and the sensor still needs a cover glass.

07-11-2021, 06:51 PM - 1 Like	#12
Philoslothical Veteran Member Join Date: May 2011 Posts: 1,889	Originally posted by BigMackCam It's mostly design of the mirror box internals and the swappable filters, with perhaps a little software to leverage them to best advantage. If somebody wanted to really engineer something like this, a set of swappable filters could be integrated and stored in the camera, just a setting away from being slid into place. You could choose among the popular wavelength filters in the field this way. A setting for no filter would be reasonable, too, for times when you want to use a filter on the lens or elsewhere in your optical stack, such as with filters for microscopes. Actually, the way some microscopes integrate filters is close to what I'm imagining, but with microscopes they're implemented on a much larger scale and generally moved by hand. The filters for a sensor would be tiny things by comparison, but they'd work much the same way, sliding in and out of the optical path. I think such a camera would be very nice and worth the additional expense to some people.