As usual a great set George!
Some look rather highly saturated to my eye (especially the F3 car in no 7).
Though I have to admit many people seem to like their TVs on maximum saturation - which would drive me mad!

For fixed cameras the maximum with out trails is highly dependent on the focal length (the '500 rule' gives a rough idea of this - a 300mm lens on APSC it works out about 1 second).
The brilliant shot of Andromeda with a long lens must have been taken with a tracking mount as this is well outside the limit for trails at 450mm EFL. I suspect the movement needed is beyond the range of astrotracker (O-GPS). If not it's even more impressive than I thought!
Taken as single shots they must also have needed some real good dark skies!

With a little ingenuity you can arrange a setup to project the suns image onto card & then photograph that.
Welding glass of shade 13 or above held in front of the lens will reduce the light (including UV & IR) to safe levels. It might soften the image somewhat more than solar safety sheet, but it's also VERY much cheaper (My Gold welding glass filters where ~£20, standard green ones are ~£2).

I used projection via a telephoto lens to watch a transit of Venus years ago (but didn't photograph the image) More recently I've taken sun spots via welding glass.

No not incorrect, though near infra red includes all the wavelengths a silicon sensor is capable of detecting. IIRC it's normally considered to go as far as 2000nm. For reasons I've never really understood min IR wavelengths are quoted as 'wavenumbers' in cm-1 (in spectroscopy at least, where I deal with them at work)

Using filters with a cut below 720nm on a non-converted camera is highly unusual. I'm surprised the results are any use at all, let alone fantastic like these !

I've got a 680 somewhere, perhaps I'll give stick it in my DSLR bag as on the modified camera it's not proved a particularly interesting choice.

I love the shots of the lock keepers house, the somewhat overgrown look & unusual architecture works really well in IR.

That's right, 720 is basically a 'standard' 720nm R72 filter. The 680 (680nm) is one of the 'colour' options where a little more of the red wavelengths are transmitted, allowing more leeway to process false colour images.
The numbers quoted are the 'cut off' generally the wavelength with 50% transmission, though a fair margin of error seems common here.

Other common wavelengths for IR filters include 560nm, 590nm, 860nm...

You say these are just firmware issues but perhaps the processing power is simply not available to carry them out with video...
In stills processing can take 1/10s per shot without being detrimental to camera use. For video you can't take more than 1/30s because the next frame is underway...

Thanks for that, not much I can attend - only 1 within ~100 miles at a time I'm around, but bookmarked for future reference anyway.

I see planning for Sept 15th 2026 is already underway, what's so special about that???

As expected a great set George!
No.s 3, 7, 8 & 13 are my favorites as I have practically nothing like your portraits.

Despite having little time for shooting I've only been through shots on one of the cameras I used - sorting the IR shots always takes longer. (None of mine where Pentax as I was working and need to keep my kit more discrete/compact)
I was quite pleased with some of the panning shots I managed whilst with you & Peter on Saturday morning, chatting with 2 Pentax users must have helped inspire me
My better shots from here have now made it to Flickr (link in my sig. if interested)

I didn't manage any on the Grid - I was called back to meet the MD just as the cars started coming through, and there was never really time to grab the camera the rest of the weekend after that

Recuva didn't work for a Barn owl shot that windows decided to enlarge my selection to include (needless to say my favorite of the many efforts I was keeping).
I noticed it had gone immediately after deleting it direct from the SD card. Said card was then isolated until I had Recuva installed so this should have been the easiest recovery ever. None of the other packages I've tried have got it back either - loads of fragments found, but nothing I can open in any viewer

Hope you have better luck Reso!

Unfortunately calling it a lens gives the potential for confusion with a dedicated macro lens such as the DA100 Macro... IMO 'filter' whilst inaccurate is easily understood.

I try to refer to them as 'close-up diopters' myself - but that probably confuses loads of people too. (The number of the filter/lens '+1', '+2' etc is technically its strength in diopters).