a few more IR

used a 680 filter on this which lets a bit more visible light through, it gave an interesting effect with the shade created by the group of trees hence the title
Frosty Day



usual 720 filter, false colour processed
Lock Keepers House



720 filter Black & White
Cerney Wick Lock

Love the Lock Keeper's House, the false colour effect works very well.

Regards
David

thanks David, there are 5 of them altogether over probably a 10-15 mile stretch of the old canal. 2 derelict, 3 lived in, one of which was rewired by yours truly many,many years ago.

No 2 is awesome. AS David said, the false color works extremely well here.

The second two images bring to mind Eastern Europe. Don't know why either. Great framing and angle of view. Are these lens filters your quoting wrt 680 and 720. I understand the filter pass wavelength but ponder what/where they are.

Best regards

Really like 2 and 3. They're gorgeous. #1 does nothing for me I'm afraid. Are these on a converted camera?

We have what was a stretch of the Chesterfield canal in our back garden, it was the first of a flight of 13 locks. The stonework is still there, but the lock gates and machinery have gone and the lock-keepers cottage has been demolished, although we have some old photos from around 1900 of some schoolchildren standing around the lock, in what is now our garden. It's not as picturesque as your image though!

Regards
David

not sure where the design for them came from, maybe from the days of the Raj as they are Victorian. ref the filters, i believe the numbers represent the IR wavelength they let through so in my case 720nm and 680nm , the lower the value the greater the amount of visible light that passes through as well. they are classed as near IR , close to the visible spectrum. some use 850 and even 950 , these are heading towards the heat spectrum, the images from these are usually processed as black & white images as very little visible light penetrates through. if i am wrong no doubt i will be corrected but this is my understanding of the filters used.
not converted just a standard K5 11s,

I totally agree

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...

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.

Very nice... No.2 for me too... The restrained use of false colour really suits it...

Best

+1