baroleum

I purchased an infra-red lens to attach to a Nikkor 35mm 1.8 on my Nikon D7100. I've exposed at 20 seconds and the pic was all red in my LCD and at 30 seconds and the results were a white LCD. Is the D7100 too effective at blocking IR?

mechengvic Loc: SoCalo

An easy test. Turn on your camera with a regular lens on it and point your TV's remote control at the lens. When you push a button on the remote, you should see the sensor on the remote light up on your camera's monitor. That tells you your camera is picking up infra red light.

baroleum

Thanks! I'll try that.

sueyeisert Loc: New Jersey

Your picture turning red is normal. I don't think you can do a custom white balance with the nikon. I suggest you go to life pixel.com (they do camera conversions) and read all the info on their site.

DwsPV Loc: South Africa

Baroleum,

Not sure what you do with the image after you have taken it i.e. post processing.

But, if you try and edit an IR image just as you would a normal image, it will not work. It has to be edited in Photoshop and there are a few ways to do this. I would suggest a few YouTube tutorials.

I believe it only works in RAW too. You should be able to set up the shot:

- lowest ISO you can, 100 on the 7100 I believe.
- F8 should be the lowest you go for aperture. On a sunny day, 16 still works.
- WB auto is fine
- Shutter - experiment with this, but in reality you should take the shot like you would normally in daylight. Your only issue is focus because the AF will not work through the filter. You have to manual focus, add the filter, take the shot.

Remember, very little IR is visible after dark. The IR changes as the daytime/ light/ humidity/ temperature changes. The IR filter is there to capture the IR reflected off an object, not reject the IR. Manmade objects have no IR, only nature....

By the way, aiming the unfiltered d7100 at a TV remote will not reveal anything - the camera will block it. Phone cameras are less sensitive, and will show an IR light.

For one, take the image into PS, select IMAGE>ADJUSTMENTS> Channel mixer. With the Red output channel, change the red from 100% to 0. The slide Blue from 0>100%. Notice some change.

The select the Blue output channel and do the opposite. Red>100% and Blue?0%.

Now you can play with the sliders of RGB a bit more to get the desired effect. After this, apply your usual edits of brightness/contrast/sharpening - whatever.

As a question - what value is the filter? You should have a number followed by nm i.e. xxxnm or similar. My guess with the red, you're probably about 500ish? That would explain the red. The white means you have exposed for too long.

Apologies if I gave too much info that you may already know, but maybe someone else will then learn from this.

Cheers
DwsPV

GC likes NIKON Loc: East Greenwich, Rhode Island

I tried my D7100 with a Hoya filter and was very disappointed with the results. Get an old D70 off Ebay. It is much more sensitive to IR rays. I also use my P7000 Cool Pix with good results !!

UtahBob Loc: Southern NJ

Look at this page first:

http://dpanswers.com/content/irphoto_sensors.php

You should indicate which ir filter you purchased. A good start is one that is 720nm such as a hoya 72.

I can see the tv remote on a D7000 but I can't get an appropriate IR photo out of it after trying to custom white balance and post processing, etc. You can get an image out of it but not the false color images with the deep skies and white/yellow foliage that come from post processing properly.

I can get usable b/w ir images out of an old olympus 4mp but with a D70 I can get the appropriate image in camera and have an appropriate base to start post processing to get the classic false color IR images. You can also bracket and do some hdr.

I find it is easiest to just look at the histogram when shooting once you have a feel for what the exposure needs to be. The D70 also lets you use very short exposures of a second or less so wind and sky are less blurred in the final image. Using an older lens also helps since most will have an IR mark on them and getting the focus right will improve your photos. The visible light focus will be different from the ir.

baroleum

Thank you so much. You gave me great support. I did forget to set my aperture high (the main reason I chose that lens - duh!). I'm saving your instructions for post processing. I did not get any indication when I pointed the remote and was very discouraged until I saw your notes. The Hoya RM72 (52mm) was 70% off on Amazon minus my rewards points = $16.67. Not too shabby. Now, I'm excited. Thank you.

UtahBob Loc: Southern NJ

I also do a levels adjustment prior to the swapping. See here:

http://www.lifepixel.com/tutorials/infrared-photoshop-basics

The 35 mm should give you good results. I generally use an old 35 mm 2.8 PC because it has a manual aperture control on the front of the lens which makes it easy to be wide open and then stop down for dof. Some lenses have hot spots so watch for that (eg 12-24 tokina is not a good candidate).

This has some useful info also:

http://photography.tutsplus.com/tutorials/an-in-depth-guide-to-infrared-photography-processing--photo-9540

baroleum

I've read that about the early Nikons being less sensitive to IR. I'll try it on my D40. Thank you.

UtahBob Loc: Southern NJ

You are all set then. Just follow the white balance setting in the lifepixel article and make sure your lcd shows something close to the second image in that article. You'll be set for post processing for sure. Shoot raw and bracket also using the histogram. Blown areas for me start showing light blue for me on the lcd.

For the white balance, shoot some grass up close with the IR filter on the lens wide open and keep tweaking the shutter speed until you get a "good" and then take an IR shot of your subject and make sure it looks as suggested above. You have to do this each time the environment changes.

You are going to like the results!

GPappy Loc: Finally decided to plop down, Clover, S.C.

Your shots will be red and require a color swap in PP. If it came out white, you're over exposed.
Set the shot up without the filter, install filter and take shot. It takes a little time and experience to get the exposure right.
I was using "Raw Therapee" for color swap most of the time. (It's a freebee program) GIMP also works and is a freebee too. Now I am using PSE with some plugins that do the color swap with one click.
Lifepixel and Kolari vision are good places to learn about IR and have good tutorials and plugins available.
By all means have fun with it. I ended up with a converted D70 to get away from the long exposures required with the screw on filters.

MW

By "lens" do you mean "filter"? Anyway, I tried IR filters on a D60 and found that getting an acceptable exposure was tricky and tedious. I basically just ran a series: 5 sec, 10 sec, 20 sec ... etc and picked the one looked best. After this first experiment, I took the camera with the filter on and used the front lawn as a target to set a custom white balance.

The RAW (NEF) will come out red. That is normal. I next import it in to Lightroom and convert to B&W. The result is very low contrast - the histogram is a very narrow peak somewhere on the graph. Using the histogram as a guide I apply a combination of exposure, contrast and black and white point to spread the histogram out. After that I start to fine-tune the result.

baroleum

Thank you for your good advice.

DwsPV Loc: South Africa

I use a converted D70 with a 530nm filter. I can shoot as normal using AF and adjusting aperture and shutter speed as normal. Never below F8 and then just process from there. I have posted images before on UHH if you want to look at old posts.