To IR or not to IR

[Dick S]

Ok, I have decided "TO IR" and sprung for the Hoya R72 filter and it works excellent. I love it. Have got some really (IMHO) classic IR shots. The one thing I'm waiting for now is the middle of summer when the bikini's come out and try to find out through IR who has silicone and who doesn't!!!!!!

Nuff of that stuff.

My decision now is whether or not to "NOT IR"

Ok, we all know the G1 has good sensitivity in the IR spectrum.

QUESTION: Does a "Hot Mirror" filter that BLOCKS the the IR part of the spectrum help eliminate some CA and/or contribute to the over all "purity" of the captured image without having to go to the digi darkroom?? How many f-stops does it cost??

Anybody tried one??

Any recommendations? Am I wasting my money buying one? Would I be better off forgetting the hot mirror and spend the money to send a case of beautiful Temecula Valley Wine Country wine over the hill to Nahau??

Regards,

Dick S, Temecula (obviously) CA

[James]

I'd love to see some of your IR bikini photos Dick... :D

MOre seriously, is the Hoya filter also available for the Pro90?? Does anyone know??

Thanks for the input.

[Dick S]

Hi James
You bet it is. Try B&H
All my filters are 58mm

Regards,
Dick S

[Rick]

Hi Dick,

Im very interested in whether the Hot Filters will work to reduce the amount of Chromatic Aberation in the Pro90. I looked all over Canons site and could not find a spectral sensitivy chart on the lens chip combination. This would be a great start in matching it to the proper Hot mirror filter I think. Please let us know the outcome of your using one.

Im looking forward to your trial.

Thanks

Rick

[Shabok]

Hi Rick,

Since the CCD used by the G1 is manufactured by Sony I found this url (http://www.sony.co.jp/~semicon/english/90203.html) containing datasheets of Sony's CCD image sensors. Just click on a 1/1.8" 3.24MPixel datasheet and you can find the Spectral Sensitivity Caracteristic in the document. Of course, it excludes the lens and a potential filter Canon would have placed between them... Another factor that could also matter is a possible amplification of some channels during the acquiring process !?!

Nevertheless, the chart indicates that the red channel has a relative response of 60% @700nm, which is quite high, isn't it ?

Shabok

[John - NJ]

OK, I've held out as long as I can. What is IR?

[Rick]

Dick,

Thanks for the link and your right that is very high actually. I think the response to IR (Infrared) is exceptional in these cameras and Im looking forward to using it quite a bit. I should have my 87C filter by Monday, unfortunatley B&H didnt get the shipment out in time to get it for the weekend:-( so I could play.

I also have about 6 rolls of Kodak IR and will shoot it at the same time through an Olympus IS3 against the Pro90 and the filter. Ill see about putting some matching images up when I get it processed. Im very interested in seeing the results and how the sensitivty compares.
BTW one of my class projects back in the early 70's was photographing women walking through the airport with IR film. You wouldnt believe how transparent silk is:-)

Rick

P.S. I have found that the Pro90 is very close in operation and feel to the Olympus IS3 and thats one of the reasosn I bought it. Both are exceptional cameras.

[Shabok]

John, here are some explanations :

http://www.rit.edu/~andpph/text-infrared-basics.html

Shabok

[Dick S]

Hi Gang,

If you are still there--I haven't forgotten about this topic.

I have a bunch of "useless" info on hot mirrors (anti-IR)and believe it or not from Tiffen, Kodak, and Canon who make/made them and B&H who sell them.

I have also done some sensitivity tests with the G1 on passing IR for IR photos.

The full "400 page" report will be posted in a day or so!!!!!

The real answer to the hot mirror issue is going to be to find someone who has actually used one of them.

Regards,
Dick

[sjguenard]

Shabock wrote:"Since the CCD used by the G1 is manufactured by Sony I found this url containing datasheets of Sony's CCD image sensors. Just click on a 1/1.8" 3.24MPixel datasheet and you can find the Spectral Sensitivity Caracteristic in the document"

Has anyone got the actual URL?

What seems to be best filter for IR?

Any focusing issues? as IR focuses behind the plae of visible light

[picnic]

sjguenard wrote:
Shabock wrote"

What seems to be best filter for IR?

Any focusing issues? as IR focuses behind the plae of visible light


I am using the Hoya R72 with good results and don't seem to have any focusing problems. I start at f6.3 to take advantage of the DOF--becuase of the focusing issues.

Here's my IR gallery.

http://www.pbase.com/picnic/infrared_gallery&page=1

Diane

[Balthus]

Hi all,

I would be really interrested in taking IR pictures but it's not so obvious which filter works correctly with the G1 and which doesn't.
Some website says that the G1 is not so sensible in infrared, some says it is.

Does anybody of you who has IR experience tried the following filters :
- Hoya R72 : Seems to work pretty well (I've seen picnic pictures which are really nice)

- Tiffen #87
- B+W 092
- B+W 093
- B+W 099
- Hoya RM-90
- Heliopan RG 715

Has anybody tried all these filters? Would it be possible to find pictures taken with a G1 and these filters to compare the results?

I know I'm quite demanding but since the price for these filters are so high I prefer to ask before buying it.

I've found an interresting url but there are no pictures with the different filters :(
http://tedfelix.com/IR/

Thanks for your answers and comment

[picnic]

balthus wrote:
Hi all,

- Hoya R72 : Seems to work pretty well (I've seen picnic pictures which are really nice)

- Tiffen #87
- B+W 092
- B+W 093
- B+W 099
- Hoya RM-90
- Heliopan RG 715

Has anybody tried all these filters? Would it be possible to find pictures taken with a G1 and these filters to compare the results?




I think most everyone using the G1 is using the Hoya R72 and perhaps the #87. From what I understand, the others are perhaps too dark. You might ask this on the dpreview.com Canon forum also and see if you get any response, but when I locate some IR photographers, they all seem to be using the R72. I got the Hoya for about $36 from B & H, I believe, and it serves my purposes quite well. I, perhaps, am not shooting what others do as much---not lots of 'foliage', which is what shows up so surreally white, but rather I like the effect it has with light and shadow mixed.

Philip Ganderton has just added a Hoya R72 to his accessories and the several shots I've seen of his were very very nice.

Diane B

[matthew]

You asked this question 7 mos ago.
I have seen a page with RG715 pics on it, I can look it up again if you want to see it. R72 seems to be very popular, naturally. I was just viewing a RM90-Hoya on Ebay and thinking of buying it. Want to go in half-and-half with me and see what pics come out like? ;)

Its a 52mm lens. Did you ever find out any more about other possible infrared lenses? I see Tiffen 25 is another IR lens, but i cant find much about it....

[4walls]

I have been toying with the idea of buying an IR filter for my G3.
Instead, for now, I am going to try to cheat... if you are interested in the
IR effect but don't want to spend the $40-50 USD for the filter, try this out.

Photoshop IR techniques (http://graphicssoft.about.com/gi/dynamic/offsite.htm?site=http%3A%2F%2Fwww.nickgallery.com% 2Fweb_pages%2Ftechnical%25207.htm).

[Roumen]

Dick,

Regarding the IR and filters - much more important is your camera IR sensitivity rather than the filter. Hoya R72 is a popular filter for infrared - you could buy one from www.lensmateonline.com.
Regarding G1 /or Pro 90/ - it is one of best suited camera for infrared and it is possible to shoot in IR without tripod in bright sunny day (speed 1/30 to 1/10 and ISO 50, 100 or 200).

Some links for IR photography from my previous post:
http://forums.dpreview.com/forums/read.asp?forum=1010&message=5959526

Greetings,
Roumen
www.pbase.com/mysamples G1 handheld IR samples