24 replies to this topic

[StephanN]

First things first:

UV photos: EOS 6D, b/w maxmax-conversion with 330C and S8612, Soligor 21mm
VIS photos: EOS 5DSR, Canon EF 11-24mm
IR photos: EOS 6D, 700 nm conversion, EF 16-35mm and 11-24mm

Due to these differences, the angle-of-view is different, also I took some of the UV-photos on a different day.

The first sets of photos were taken at a church nearby (https://de.wikipedia...St._Margarethen).

It is amazing, how repair works at the walls can be all but invisible in IR and VIS, but hit you over the head with a mighty big hammer in UV:







Next, the colours used in painting buildings, especially the yellow found on plenty of churches, don't always show up in IR and UV, also the huge golden crucifix is rather boring in IR and UV.







With the next three, I cheated a bit, as they were taken from the church, overlooking the danube, so not quite a photo of ecclesiastical (Yes, I had to look up how to spell this word) architecture, but there's cross in it, so it counts sort-of. I converted all photos to b/w, just to emphasize the differences (the UV-photo was taken from a triped, as there was not enough sun)








The last set was taken at a monastery (https://en.wikipedia...Wilhering_Abbey , I tried some photos in the church of the stunning colours but both IR and UV are just dull, of course). The pink/brown/salmon colour used here does show up in IR and UV, which might also mean that they used different materials here than in the white parts.








Bonus photo: the chapel does not look very nice in IR, but I like the colours and the lines.

Edited by StephanN, 06 February 2021 - 18:30.

[Stefano]

Nice images. The second one (the first infrared image) looked similar to a visible light image to me at first glance, and even reminded me of tri-color IR. Also nice how you can see different paints in UV.

[Andy Perrin]

Very nice! The one at the end with the cross by the river is a little creepy even. I wonder how an IRG image of the inside of the church would look.

[Bernard Foot]

Yes, the first UV image is astounding, the way it shows up the repairs. I didn't know that UV would do this. I'll have to start trying that out. It would be intresting to see how those repairs appear in tri-colour UV.

[Stefano]

Enrico Savazzi had a similar image (comparison). I'll try to find a link.

Here it is: http://www.savazzi.n.../P7110006cs.JPG
http://www.savazzi.n.../SUV04719cs.JPG

Site: http://www.savazzi.n...tography/uv.htm (scroll down to see the images linked above).

Edited by Stefano, 06 February 2021 - 21:54.

[Cadmium]

Stephan, Wonderful architecture and photos! I especially like your first and second sets.

[OlDoinyo]

I think photo 3 highlights the difference between titanium dioxide white paint (which absorbs below 380) and something else (perhaps calcimine?) which does not.

[colinbm]

Great series Stephan, particularly the UV interior of the Church.

[StephanN]

Andy Perrin, on 06 February 2021 - 20:35, said:

Very nice! The one at the end with the cross by the river is a little creepy even. I wonder how an IRG image of the inside of the church would look.

Bernard Foot, on 06 February 2021 - 21:24, said:

Yes, the first UV image is astounding, the way it shows up the repairs. I didn't know that UV would do this. I'll have to start trying that out. It would be intresting to see how those repairs appear in tri-colour UV.

Thanks. You know, I've been reading the threads about tri-colour UV, tri-colour IR, IRG and the other multispectrum variations with interest, and what has held me off so far are the usual three problems: First, how to get all the necessary band-pass filters (in a large enough filter size) and not go bust, second how not to screw up swapping filters and memory cards around, and third how to process the photos in Photoshop and not mess things up completely.

It is obvious that on that day I didn't have any multispectral images in mind, so not sure how the chances are to get an tri-colour UV-VIS-IR photo with cropping and aligning in photoshop. In this rather small church I was almost with my back to the wall, so not being able to move back any further to allow the usage of an EL-Nikkor or the likes, in order to take multispectral photos with small filters, I would probably have to make hundreds of exposures

The IRG might work better, because they've been taken with the same lens; still, not using the tripod for these so definitely not the same angle.

Bernard: I've tried following the link to your seller of UV-bandpass filters on EBay in one of yor threads but it came back "broken link". Can you provide me with a working one?

Also, does anyone have experience with IR-bandpass filters, I've seen that Maxmax is offering a set of them, up to a diameter of 72mm.

[StephanN]

Stefano, on 06 February 2021 - 21:47, said:

Enrico Savazzi had a similar image (comparison). I'll try to find a link.

Here it is: http://www.savazzi.n.../P7110006cs.JPG
http://www.savazzi.n.../SUV04719cs.JPG

Site: http://www.savazzi.n...tography/uv.htm (scroll down to see the images linked above).

Thanks, I've been to his page long time ago, perhaps this image was lurking in the back of my mind.

[StephanN]

Andy Perrin, on 06 February 2021 - 20:35, said:

Very nice! The one at the end with the cross by the river is a little creepy even.

How about this for a creepy, haunted house on the hilltop, taken from the graveyard (vis and ir not nearly as creepy)

Attached Images

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[StephanN]

I got one more, I was not able to get the frontal view with the Soligor, this scene was on a little hill by the church, so I couldn't go back far enough.

Edited by StephanN, 07 February 2021 - 06:28.

[Bernard Foot]

StephanN, on 07 February 2021 - 06:14, said:

Bernard: I've tried following the link to your seller of UV-bandpass filters on EBay in one of yor threads but it came back "broken link". Can you provide me with a working one?

Also, does anyone have experience with IR-bandpass filters, I've seen that Maxmax is offering a set of them, up to a diameter of 72mm.

I assume the link for the UV bandpass related to Omega optical. Unfortunately that supplier is no longer operating, and I don't know where else you can get UV bandpass filters at a reasonable price.

For IR, though, I think there is a better (in terms of price) option than Maxmax - Midwest Optical (midopt). They do a lot of bandpass and longpass filters for IR and visible (but nothing really for UV), and their website provides all the transmission data. Then goto ebay and look for the dealer discount-optics . He has a lot of midopt filters at low price. He often has stock which is not yet listed - so it is worthwhile to contact him and say what you need in terms of filter type and size, giving what options would be acceptable, and he'll tell you what he's got. If you buy multiple filters, he'll put a bundle together for you to save on postage.

[StephanN]

Bernard Foot, on 07 February 2021 - 09:29, said:

For IR, though, I think there is a better (in terms of price) option than Maxmax - Midwest Optical (midopt). They do a lot of bandpass and longpass filters for IR and visible (but nothing really for UV),

Cool. They offer two near-uv filters under the group Bi series here: https://midopt.com/filters/bandpass/ , apparently new items, which look promising. The Bp-group filters are generally too broad, I think.

[Bernard Foot]

StephanN, on 07 February 2021 - 11:02, said:

Cool. They offer two near-uv filters under the group Bi series here: https://midopt.com/filters/bandpass/ , apparently new items, which look promising. The Bp-group filters are generally too broad, I think.

Last time I used discount-optics he didn't have any BI filters. But the BN filters have a narrower bandwidth than the BP range.

It depends on what you want to do, but a broader bandwidth may not be an issue. If you look at the RGB filters on colour film or digital sensors, or in the human eye, the bandwidths are broad and overlap. If they didn't overlap, you might lose colour nuances - for example, something that was a very specific yellow colour would trigger either the red or the green channel but not both, and so would be misrepresented.

[StephanN]

Bernard Foot, on 07 February 2021 - 11:14, said:

If they didn't overlap, you might lose colour nuances

True, I'll have to select the filters carefully. Presumably the following would work ok for tri-colour IR: BP735, BP845, and BP1000/BN940.

However, for UV there's no way around Bi-filters (when sticking to midopt, that is), so BP250, Bi350, and Bi385 might be acceptable; it's a pity they don't offer something like a Bi310. Still, there's the question mark of camera+lens reaching down to around 300, which is about the limit of the BP250, perhaps cheating and using the Bi405 will give better tri-colour results, even if it's no longer true UV, then.

I'll have to think about this a bit more, I guess. Well, I don't expect to get my shots against you-know-what until summer, so plenty of time to play around with taking photos until then.

[Bernard Foot]

StephanN, on 07 February 2021 - 11:50, said:

True, I'll have to select the filters carefully. Presumably the following would work ok for tri-colour IR: BP735, BP845, and BP1000/BN940.

For tri-colour IR I am using BP735+R72 (as the BP735 leaks some red), BN850, and LP1000, but the BP845 and BP1000/BN940 should work.

I haven't used midopt UV filters. I think the BP250 probably won't work - only 2.6% transmission at 320nm, when your sensor+lens combination are already very poor (my Omega 315BP25 gives about 75% transmission at 320nm). The BI filters look OK. Your problem may be finding these filters at a reasonable price - I don't think that discount-optics has them, but it would be worth asking.

[JMC]

Really nice pictures and thanks for sharing Stephan.

Sorry if I missed it, but what was the UV light source in the first interior shot?

[StephanN]

JMC, on 07 February 2021 - 14:18, said:

Really nice pictures and thanks for sharing Stephan.

Sorry if I missed it, but what was the UV light source in the first interior shot?

Thanks. The light source was the sun, filtered through the church-windows, therefore it was quite gloomy. That's why I had to resort to the tripod and multiple exposures, even then I had to use ISO 1600 and 30s (f-stop probably 11, a bit excessive, for a 21mm-lens) for each of the 5 exposures. In comparison, the VIS-shot was at ISO 6400, f/4 and 1/100s - in hindsight, I could easily have gotten away with half the ISO, given that I used the lens at 11 mm, or even a quarter (IR was ISO 3200, f/4 and 1/13s).

[Andy Perrin]

StephanN, on 07 February 2021 - 11:50, said:

True, I'll have to select the filters carefully. Presumably the following would work ok for tri-colour IR: BP735, BP845, and BP1000/BN940.

However, for UV there's no way around Bi-filters (when sticking to midopt, that is), so BP250, Bi350, and Bi385 might be acceptable; it's a pity they don't offer something like a Bi310. Still, there's the question mark of camera+lens reaching down to around 300, which is about the limit of the BP250, perhaps cheating and using the Bi405 will give better tri-colour results, even if it's no longer true UV, then.

I'll have to think about this a bit more, I guess. Well, I don't expect to get my shots against you-know-what until summer, so plenty of time to play around with taking photos until then.

Ah, those filters let through tons of IR. Boatloads. Especially if you wanted to do tricolor, you will have to block it really really well. Which is itself a problem because I think even S8612 will cut into your UV out in UVB. The wonderful thing about omega filters is that they had at least some IR blocking (although sometimes it needed assistance).