Opaque filters for IR shooting

Hello

 

I've been using Kodak HIE with a deep red #29 filter with very good results.

However, since they are discontinuing it, I will be trying out the Rollie B/W

IR film. In an effort to simulate the Kodak look, I think I may have to go with

an opaque IR filter. What is the approximate filter factor for the opaque

filters?

 

Thanks

Russ<div></div>

A lot depends on your setup, but I'll pass on my experience with B+W 092 (89B equivalent)

versus 093 (87C equivalent). The latter is opaque and needs about 2-3 more stops than

the former with HIE. If you deal in filter factors, that's about a 4-8 multiple. I'm not sure

how it would work out with the Rollei film, but it's probably a good starting point for

bracketing. Good luck, and please let us know how it works, if you try it.

I just started shooting Rollie, I use a Hoya 72R opaque filter. My advice is, d/l the fact sheet on the film and read it well. It will give a lot of info, I am finding filter factors of about 6 to 8 depending on conditions. I was shooting SFX 200, same filter and found that with the filter on, and using my meter inside TTL, if I set it to the perfect exposure, I got exactly a perfect exposure, but SFX is in the low range of IR, and I think my meter is a little more IR sensitive, but this is only with SFX, you won't find same results with Rollie. 6 to 8 stops is what I am finding, but I am bracketing also, still practicing, so as I learn more I will contact you. The Hoya 72R is a great filter by the way, I got EXTREMELY good wood effect and results with SFX, which is only sensitve up to 740nm, Whrereas HIE was up at 900nm. Don't discount SFX, its a pretty good film and with the Hoya, it will give you some good results. Only thing I am working on is trying to reduce grain in final shots so I can enlarge to 11x14, but I am going to have to experiment with developers and such.

 

Good luck and give the Hoya 72R a try, you can pick one up on ebay for about 45 bucks, and try some SFX 200, you might be impressed!

 

Luke

RG715 (715nm) and Hoya 72R (720nm) is the best option. 4-6 stops depending on the IR atmospheric circumstances.

 

http://gallery.fotohuisrovo.nl/thumbnails.php?album=2

 

and

 

http://gallery.fotohuisrovo.nl/thumbnails.php?album=10

 

You can load and unload in subdue light.

 

Best regards,

 

Robert

HEy RObert,

 

Just to clarify, you are saying 4-6 stops meaning take the reading TTL without the filter, put the filter on and Increase time by 4-6 stops, or decrease time by 4-6 stops?

 

I am not meaning this as you are wrong, I just wanted to clarfy what you meant in Stop direction cause im gonna try what you said, I was told 6-8, but I haven't seen my results yet.

 

Just a clarification. And by stops you arn't stopping the apature down or up, you are using time stops right?

 

Luke

Thanks!

>> 4-6 stops meaning take the reading TTL without the filter, put the filter on and Increase time by 4-6 stops, or decrease time by 4-6 stops?

<<

 

Exactly. (Or measure with an extended exposure meter so that you can leave your filter on the lens :) )

 

T-stops and F-stops are giving the same end effect. But of course with the aperture you're regulating also the D.O.F.

 

Without filter the sensitivity of the Rollei 820/400 is about iso 200-400 depending on the developer. That means with the opaque filter you're working around iso 12-25.

Ok,

 

Cool, so actually decreasing the time stops is best, since when the filter is placed on, the meter will want to make a longer exposure due to loss of Visible light, but IR hasn't changed at all, so just derease the time around 4 to 6 stops and you should get a good exposure, and bracket. If you increased the time, you would probably blow out the pic by to much exposure correct?

And for sure, yeah doing it with apature, you are for sure playing around with DOF. And having stop changes of 4 to 6 can make a HUGE difference in that.

See a big thing I have a problem with is, most ppl adjust thier cameras ISO different from the actual films ISO to get the results, but I can't do that, my camera is new and reads the ISO and I can't change it, so it knows it is shooting 400 ISO film and compensates for that in metering, that I can't change, so I have to compensate in other ways.

As far as development, I am using d-76 to start, I am playing with an experiment in dilution for longer times to reduce grain, I read it in an article about D-76 from 2 retired Kodak Chemical Experts. I haven't started yet, but I am going to do one roll with stock as usual, then one roll 1+3 diluted and see if it made a change.

 

Gosh I have been reading and researching IR so hardcore that my mind is starting to screw with me and confuse the heck out of me from info overload. That is why I was asking about the stop direction, meaning increase time, or decrease time in stops to compensate for the filter and the TTL meter.

Unforttunatly I don't have an external meter, however I guess I could use my digital, set it to 400 ISO and use it as my meter, but im not sure about that, cause I am shooting Nikon camera film, and Digital is Canon. To bad I don't have an external meter. Getting one as soon as I can afford it, my friend got one not long ago, was about 250 or 300 bucks, but it was SWEET! And worked like a charm.

Well worth it.

 

Thanks!

 

Luke

The latest Rollei developing table:

 

http://www.fotohuisrovo.nl/documentatie/Development_Rollei%20films.pdf

 

Always shoot a negative WITHOUT filter so that you can check your development later.

 

A lot of things are depending on the local atmospheric IR conditions, therefore always do a bracketing in the beginning. Later you know exactly what to do.

Also take notice to correct the distance due to the fact IR light has a different breaking index. Correct on the red IR dot on your lens for 800nm.

 

 

Regards,

 

Robert

 

(Dutch Rollei/Maco distributor)

http://www.FotohuisRoVo.nl

Hey RObert,

 

I know I am asking a lot of ?'s, sorry, but I am learning a lot. You said, always shoot one negative without the filter on to check your development later.

 

Can you explain this a bit more, like what you mean by checking the development? So when I shoot that one neg without the filter should I just meter a proper exposure and shoot. What should I expect to see? I haven't done that before..lol..always had the filter on.

Honestly, I have been doing development and processing for 20 yrs, but I haven't really got into crazy developers and wild experimentation different mixes and times, and such. I have always gotten great photos with pretty simple development procedures used for 20yrs, but I am learning more and more in this forum about it. Especially since I started with IR.

was just curious what you meant about the shooting one without the filter to check development. Oh, and yeah I do correct the focus to my dot, mine is white, I use a 35-70mm 2.8 Nikkor mostly and it has 2 marks, one for 35mm and one for 70mm. I will focus then whereever the lens mark is, I will just dial it back or forth to put it over the 35 ot 70mm mark depending on how much I have zoomed in or out, 35 or 70.

 

Thanks for taking the time to explain these things, it is really helpful and I am very appreciative!

 

Luke

What am I thinking, man my brain is about mush, I know why you said shoot one without, cause it is just black and white film, its just more sensitive to IR, so its just gonna be a regular B&W pic, then you can compare to make sure you developed correctly to the actual filtered shots..geez man I am loosing my mind. Sorry bout that Robert, just wasn't thinking, I think I need to put the books away and stop reading for awhile and let my mind get all the consumed info filtered out and settled in. lol..believe me, I have been reading so much on IR and developing and these threads that I think I am in overload now, asking dumb ?'s..

 

Thanks a bunch for your help!

 

Luke

Is there really such a thing as a filter factor for an IR filter? I mean it is just filtering out the visible light, so the IR film is working as normal, and exposure won't be measurable by a light meter anyway, right?

 

I've only shot IR on digital cameras where the problem of exposure is complicated by the need to get around the built-in IR filter (since sensors are very sensitive to IR-some of the early digital cameras were infamous for producing IR body detail through clothing). Because of the filter (some people who really like IR have the filter removed from the front of the sensors), exposures are very long. The only good thing about IR on an unmodified digital is that you can see the results right after you take the picture, and trial and error your way to proper exposure.

Luke,

 

Sorry to bring your brain in "overload", but indeed an IR film without IR filter is reacting like a normal panchromatic B&W film and therefore you can check on the negative without filter if your regular development parameters are really OK. So simple it really is.

 

I can recommend you the book written by the actual C.E.O. from Rollei-Maco Mr. Hartmuth Schroeder: Schroeders Negativ Praxis, multi language and a pretty big part about IR photography.

 

http://www.fotohuisrovo.nl/documentatie/Schroeders_N_P_Infrarot.pdf

 

 

@ JDM: Yes each filter has it's filter factor, however the actual measurement of IR light is impossible due to the fact most exposure meters are going to 700nm sensitivity or less. So the main part of IR light is just a guess which is depending on the atmospheric circumstances. But it looks more complicated than it really is due to the fact each IR film manufacturer is using a type of IR film with a quiet big latitude to compensate this "problem".

Rollei IR 820/400 is based on APX400 technology, a film with a tremendous capacity for over-exposure. Gevaert in Belgium (Mortsel) is producing all these special aireal films, exclusivly for Rollei/Maco. First class film in the past used for military specs and purposes.

 

Digital IR: Indeed to protect the CCD/CMOS for heat each digital camera is equipped with a low pass filter before the chip. Therefore the sensitivity for IR light is not very high so your effective bandwith is very small on most digital cameras.

 

It's in fact the same failure you can make by filtering the Rollei IR 820/400, which is going down fast over 750nm in sensitivity, by a 780nm filter.

RG780 means 50% transmissive light on the 780nm point.

The fact that the IR 820/400 film is on 750nm already over it's 60% on high max. sensitized point means that on 780nm maybe 30% is left and the filter is working already on 50%. So no bandwith is left an therefore apart from the 6-8 times filter factor the film is not sensitive anymore: Result: Iso 1 or less!

 

 

A nice extra feature of this less sensitized thing is that the Rollei can be loaded and unloaded in very subdue light. The Kodak HIE is going over 900nm and therefore this NOW discontinued film MUST be loaded in complete darkness. The lack of any A.H. layer causes also an extra "light piping effect" into the film cassette. It will fog half the 35mm film in a bit bad circumstances which can also happening in the lab when they do not take precautions for this.

 

Rollei IR 820/400 is available in 35mm, 120 roll film AND 4x5" sheet film.

I am just testing my Yashica MAT 124-G back from a nice C.L.A. (Will van Manen, the Netherlands) on this infra red film. A nice Bay I RG715nm filter (Heliopan) and a nice check if he has done the new foaming seals in the camera in the best way. Sure this is a critical film in each classical camera to show everything is still working 100%.

 

A TLR is one of the most convenient ways to work with IR photography and due to the fact they are all 100% mechanical you also will not have any problem with IR diodes (LEDs) for the film transport which can interfere on the wavelenght of your IR film and therefore can cause a fog stripe on your negative.

 

Not all cameras are suitable for high sensitive IR film.

 

Hope to be informative for all Photo.net readers.

 

Best regards from the Netherlands,

 

Robert

Wow.

 

Thank you for all that book info! That is some WONDERFUL into right from the horses mouth! Very appreciative.

 

I am gonna go shoot a roll later today, and play with the t-stops, lowering the TTL W/O filter from 3-7 stops, and find out just where the sweet zone is. I probably will screw up some frames, but I will find that sweet zone! lol

 

Thanks again Robert, that was kind writing all of that!

 

Luke

http://farm3.static.flickr.com/2290/2079575579_7bebd2ffa3.jpg

 

 

That's mine.....

Thats sweet!

 

I have 2 Rolliflex's but I have to get them working, I have all the parts, and they are in pretty great shape, just need to get it all fitted right and the parts back on. A guy gave them to me, he had one that he salvaged parts from, then a customer came in to have his repared, very small repair, but he never did it and the guy never came back. like 15yrs ago. So im gonna get my TLR up and going soon!

 

THats a sweet camera you have there!

 

Luke

I have not read all the posts here so forgive me if this has been mentioned but the Efke IR film will be closer to the HIE for IR effect and grain.

The sensitivity curve of the Efke IR820 film is more straight up from 750nm so even with a 665nm filter you can have some 'wood' effect. However to reach the HIE effect you also need at least a 89B (695nm) filter.

Efke IR820 is an extended sensitized Efke 100 elmulsion with above filters just reach an iso rate around 3.

Efke films are also known about their softer emulsion. These single layer films (former Dupont) need more carefull treatment.

Hey Robert,

 

The Rollie 820 you spoke of, it is actually rated at an ISO of 100? Meaning out of the box it is a ISO 100 film? Cause if so, I wish I would have ordered it instead of the Rollei 400, ISO 400 (More Grain), a 100 would have been a little less grain and remember I am not looking for much more reduction, I am almost there. the SFX200 dang near made a good 11x14, but just wouldn't do it.

So the 820 is a 100 ISO film? Remember I can't change the ISO on my camera, it automatically set reading it off the film, so I can't shoot a 400ISO film at 100ISO, or 800 ISO by changing an ISO knob. And just to clarify one more time so I make sure (cause I haven't been able to shoot due to wheather yet) I am going to be metering W/O the Filter, then putting it on and DECREASING the stops T-stops by 4 to 6 t-stops right? Not Increasing? I keep getting confused, in my sfx work, it was so easy cause my meter seems to be sensitive to about 730 or so nm, but this is different, so DECREASE the t-stops after metering w/o the filter right? So say if I metered WITHOUT the Filter at F11 and it gave me a 1/250sec Shutter speed for a correct exposure, then I put the filter on and I need to Lower that Speed by 4-6 t-stops, say 1/15th or 1/8th of a sec. or am I going in the wrong direction? I know I should know more about this, but really with all the written info and post, I am still slightly confused.

 

Thanks partner.

 

Luke

The Rollei IR 820/400 without filter you can handle like APX400 (new)/ Rollei Retro 400.

With speed enhanced developers around iso 400, developers like Rodinal iso 200-250.

A 89B filter will loose 4 stops, 88A 5 stops.

Iso: 400-200-100-50-25-12 --> --> a.s.o. each step = 1 F-stop MORE exposure.

1/250 - 1/125 - 1/60 - 1/30 - 1/15 --> --> a.s.o. also one F-stop and also MORE exposure

F= 16 - 11 - 8 - 5,6 - 4,0 - 2,8 --> --> a.s.o. also one F-stop and also more exposure.