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09-13-2016, 09:07 PM   #1
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Infrared beginner has questions

Hello:

Does the IR lens filter provide the same results as an IR-converted camera? Where can I go to learn about this field?

Any advice would be much appreciated. Thanks for providing a great market for the photographer.

Be well,

Bob

09-13-2016, 10:52 PM   #2
Tas
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QuoteOriginally posted by SmilinBob Quote
Hello:

Does the IR lens filter provide the same results as an IR-converted camera? Where can I go to learn about this field?

Any advice would be much appreciated. Thanks for providing a great market for the photographer.

Be well,

Bob
Hi Bob,

I won't claim to be knowledgeable in this field but whilst you wait for more knowledgeable members to drop by here's a webpage to read for starters: https://photographylife.com/introduction-to-infrared-photography

I'll drop back with another link shortly.

Tas

Edit: I've used filters from these guys: I-Ray Infrared Filters – 830 I-Ray and new “Custom” 690 I-Ray | Singh-Ray Filters though I've not used their IR filters. They're good quality but not cheap. I added the link as it might provide useful info on filters, the caveat being this is their business not camera conversions so please keep that in mind when reading. And more how to info: http://photography.tutsplus.com/tutorials/an-in-depth-guide-to-infrared-phot...re--photo-9533

Last edited by Tas; 09-13-2016 at 11:03 PM.
09-13-2016, 11:17 PM   #3
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Digital cameras have an IR blocking filter over the sensor. When a camera is converted this filter is removed and either replaced with an IR pass filter or left full spectrum so that one can place a filter of whatever strength over the lens. It is not impossible to use an IR filter over an unconverted camera, but, it does require either really high ISO or really long exposure so the quality isn't as good. I have done this with a Q and a Fuji X100 and the images were ok. I have been thinking about getting my old K5 converted.
09-13-2016, 11:22 PM - 1 Like   #4
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Using an IR filter on a non-converted camera will have an impact in terms of usability. Non-converted cameras have an IR blocking filter (hot mirror) usually installed in front of the sensor. Placing an IR filter in front of the lens only lets IR light through which is then mostly blocked by the hot mirror installed in the camera. Its sort of like placing a strong ND filter on a non-converted camera then trying to take a visible light photo. The net effect is that you will need longer exposure times for the given ISO and f-stop setting than you would with a converted or normal camera.

A clear converted camera replaces the hot mirror with a clear filter which can pass through all the light visible to most digital camera sensors (some UV, visible, & IR). Some folks go with this option and purchase a variety of different screw in filters (UV only pass, visible only pass, visible + UV pass, visible + IR pass, various different IR filters, etc.) in order to get different effects. The advantage of this is that your camera will not need long exposure times for the same ISO and f-stop settings.The disadvantage is that you will not be able to see anything with any filters that block visible light if you are using an SLR with a traditional viewfinder. This makes it harder to focus since you will probably need to compose, focus, then install your filter without disturbing the camera. This isn't so much of an issue if you use liveview to focus and compose. The other disadvantage is that you may need to get different sizes of the filters you like to fit different lenses. You could also get oversized filters that fit your largest lens, then use stepping rings to fit those filters on your smaller lenses. These filters are not cheap...

A fully IR converted camera replaces the hot mirror with a dedicated IR (or UV) filter will not have the same flexibility as a camera converted with a clear filter. You will only have the use of a single filter, basically whatever was installed by the tech. This is not an issue if you like the look of particular filter (UV, 590nm IR, 720nm IR, 830nm IR, etc.).

Here are some samples from an 830nm IR converted Pentax K10D. Good luck with your conversion!


The Palace of Fine Arts
The Marina District, San Francisco, California
Focal Length: 18 mm
Exposure Time: 1/250 sec
Aperture: f/11
ISO Equivalent: 400



Maipalaoa Beach Park
Maili, Waianae Coast, Oahu, Hawaii
Focal Length: 15 mm
Exposure Time: 1/180 sec
Aperture: f/11
ISO Equivalent: 400



Haleakala Rising from the Sea
Flying back from Kona, Big Island of Hawaii
Focal Length: 26 mm
Exposure Time: 1/60 sec
Aperture: f/9.5
ISO Equivalent 400


Pupukea Beach
North Shore, Oahu, Hawaii
Focal Length: 18 mm
Exposure Time: 1/180 sec
Aperture: f/11
ISO Equivalent: 400

Here is a link to my full gallery...


Last edited by HawaiianOnline; 09-13-2016 at 11:27 PM. Reason: Added exposure details
09-14-2016, 07:34 AM   #5
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I've tried using an R72 filter on several cameras. Essentially, your mileage may vary.

While DSLRs from 12 years ago (like the K100d, Nikon D70, Canon 20d) could get exposures in bright sunlight around 1/4 second or a bit longer, I discovered that models that came along later had stronger infrared filtering on board. Cranking the ISO up to 800 still ended up with 10 second exposures in sunlight with a Nikon D200. Not all cameras are that bad, but I found that the long exposures needed on my K-01 meant soft edges on foliage that wafted gently in the breeze. You don't have all the sharpness in the world to start with using infrared, so losing detail to long exposures only makes it worse.

So I converted a K-r using an R72 (720nm) and I love it. I call it my K-ir.

It's great not having to use a tripod all the time. Shutter speeds are fast enough to stop wind movement.
09-14-2016, 11:43 AM   #6
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Hello;

Lots of great advice and insights here. My 2 cents is IR shooting is very much experimental and if you read much on the subject, you will find many photographers have their own methods. The best approach is to have a camera's IR filter removed by a tech such as Photography Life. One little known fact is Sigma's SD1 has a user removeable IR filter [they refer to it in the manual as a dust protector]. He' is an article you may find useful. Good luck.

Sigma SD1 and SD15 for Digital Infrared Photography

Chuck
09-14-2016, 03:00 PM   #7
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Do a Google search on Mark Hilliard's Introduction to Infrared Photography V2. It's a YouTube video that's over an hour long but does a good job covering the ground you are interested in. He also has other videos covering IR in some depth.

Here's a link to some of the stuff I have done: http://charleskinghorn.com/galleries/barns-in-the-county-series-3/. I am using an IR-converted K-7.
09-14-2016, 03:26 PM   #8
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I would also look at the prices of the ebay seller uriroptics. They seems to specialize in filters for thispurpose. they come with lost of graphs detailing filter combos etc. and the prices are pretty competitive.

I have tried this but never got much except really bright images - hey Hawaiian what PP did you apply to get those images

cheers

09-16-2016, 05:08 PM   #9
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Thank you, everyone.
12-03-2016, 04:16 PM   #10
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QuoteOriginally posted by HawaiianOnline Quote
.......The net effect is that you will need longer exposure times for the given ISO and f-stop setting than you would with a converted or normal camera....
Thank for this informative post. My question is... about how many stops difference do you think if using a filter on an unmodified camera?
12-03-2016, 06:19 PM   #11
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QuoteOriginally posted by jcdoss Quote
Thank for this informative post. My question is... about how many stops difference do you think if using a filter on an unmodified camera?
IIRC too many to handhold.
It has been several years since my last go at IR. The K100D was "doable" handheld, K7D was not.
Have not done any with K5. So in short, for a unmodified body, a tripod most likely.

Last edited by Ex Finn.; 12-03-2016 at 06:24 PM.
12-03-2016, 06:58 PM   #12
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QuoteOriginally posted by jcdoss Quote
Thank for this informative post. My question is... about how many stops difference do you think if using a filter on an unmodified camera?
I've tried a few shots on an unmodified K-5, and a 720nm filter(cheap one from Amazon).

The only PP so far was playing with white balance. No green leaves on the trees. I'll have to wait for spring now.

ISO 500, 5sec, f16, SMC-K 24mm, in bright sunlight.

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