Friday, April 6, 2007

IR for Beginners - The Sony Nightshot Cameras

This time we are going to talk about a group of cameras with a very special Infrared Capability, unlike any other camera on the market. A few of the Sony Digital Still cameras have a feature called Nightshot. The models which have this feature are, starting from the oldest to the newest, the DSC-F707, DSC-F717, DSC-F828, DSC-V1, DSC-V3, and the just released H9.

Nightshot makes these cameras instantly IR Modded, and with the flip of the switch, it goes back to the Un-Modded color capable “Normal” state. Yes, flip a switch and these cameras remove the internal IR Block Hot Mirror filter for IR Photography, and then flip it back, and the IR blocker filter goes back into place for regular Color Photography. All of them are capable of sub-second IR exposures, and can be used handheld. All of this without paying for a professional IR Block Filter removal.

IR Photographers have thru experimentation, found ways to use Nightshot for Daytime IR Photography, and are producing stunning images with these Sonys.

As usually is the case in IR Photography, Sony owners are not Quite using this feature as it was intended by the Sony designers and engineers. So, we will start out here by describing what Nightshot was actually intended to be used for by the Photographer.

Very simply, Nightshot allows you to take an image in complete darkness, in the absence of any available light. Well we all know that the world in not completely dark anywhere but in a darkroom. But, if a scene looks pitch dark to the eye, no reasonable amount of exposure time will ever get you an image. OK, you can fire flashes, focus with laser pattern projection on the subject, and get an image. You can do these things with these cameras too without using Nightshot. But, Sony added a unique IR Capability. When you flip the switch to Nightshot mode, little IR LED Emitters built into the camera turn on, and bathe the scene in IR light. The camera moves the IR Block Filter from in front of the sensor, and, I can say this with relative confidence, adjusts the focus for IR light wavelengths. The result is an image taken in IR Light. You get a greenish image similar to the old Military Night Vision glasses. Eyes reflect the IR and glow in a very strange fashion. Taking “red eye” to another level!

So, Great! Instant IR camera! Well almost. In the Nightshot mode, you have no internal filter in the light path to the sensor. So, you will be getting ALL light spectrums at the sensor, UV, Color, and IR. Since your goal is to shoot IR, this is not what you want. You would get a color image, with strange colors caused by the combination of all of the wavelengths of light that the sensor can record. A real train wreck! Maybe you like Train Wrecks.

If that’s not enough, Sony has removed any user control of Shutter Speed and Aperture settings. The max shutter speed is set at 1/60 for the 7X7s and 1/30 for all the other models. The Aperture is also set wide open, and with the excellent glass on these cameras, that’s usually F2 or F2.2. In bright daylight, at these settings, your image will be completely over-exposed, washed completely out. Remember that Sony intended for you to use this feature only in complete darkness, so it is no wonder that the exposure will be blasted.

Sony also faced some unfortunate criticism with the Nightshot feature on some of their video cameras. People noticed that under some conditions, certain clothing fabrics tend not to reflect IR light at all, which makes them become transparent. Other fabrics, usually underclothing reflect IR well, so people started calling these video cameras, X-Ray cameras. The capability was way overblown, but in the right conditions, examples could be produced. Honestly, you can see more underwear voluntarily displayed standing in supermarket check-out lines, but as with any hysterical “problem”, a definitive cure was necessary from a corporation as large as Sony. So, Sony decided to take care of the problem by restricting the Shutter and Aperture settings on the still frame cameras when in the Nightshot mode.

So, we end up with these cameras with the wonderful “IR Mod on demand” feature, Nightshot, which is tightly restricted as to Shutter and Aperture settings, so much so that Nightshot is un-usable in anything but darkness. Well, never underestimate the determined owner/experimenter. Someone, I don’t know who, came up with the idea to add a screw-on IR Pass Filter to the lens to insure that only IR Light reaches the sensor in daylight. That left the problem of complete over-exposure. Controlling exposure is exactly what Neutral Density (ND) filters are designed for. So the intrepid experimenter tried adding screw-on ND until he/she got the exposure under control. Turns out that ND 8 works well in most bright sunlight conditions. A collection of ND 2, ND4, ND8, and a Circular Polarizer (CP) can take care of just about any daylight exposure conditions. You don't need quite this many ND filters, but I just took a shot of my collection.

This leaves only one minor problem to solve. If you will remember, I stated that when you flip the switch to Nightshot, the camera turns on it’s built in IR Emitter LEDS to bathe the scene in IR light. Well, this is not really a problem, as the camera’s IR light is simply added to the much stronger Natural IR Light from the Sun. Except in the case of the 707 and 717s. Sony placed the Emitters at the end of the lens barrel. Since you will be using screw-on filters, the LEDs will be shining onto the inside surfaces of the filters. Some of that IR Light will reflect off the filter glass, end up back on the sensor and fog your image. The solution turns out to be really simple. Block the IR Emitters, cover them up! The sun gives you plenty of IR Light, so you don’t need their light anyway. Small squares of Black Electrical Tape placed over the emitters, solves the problem, simply and cheaply. The other Nightshot cameras have their IR Emitters located elsewhere on the camera body, and do not introduce this problem, so this is for the 707 and 717 only.

So there you have it. A camera that can, on-demand be turned into an excellent IR Capable Camera, and then converted back to Normal Color Shooting. I have a Sony 717, and I don’t ever use Nightshot to shoot those Night Vision type images, so I have the IR Emitters covered with black tape all the time. If I want to use the camera for IR work, I simply screw on my Hoya R72 IR Pass Filter, and usually an ND 8. I may adjust the ND depending on lighting conditions, but usually it is a no-brainer use of the R72 and ND8. Flip the switch over to Nightshot, and I’m shooting IR at 1/60 second. That is usually fast enough to stop most action, and give an acceptable handheld IR shot. The other models restricted to 1/30, can be shot handheld if the photographer practices steady hold techniques. Short of that, a tripod or monopod will work well to steady the camera.

One final thought and one that was brought up in the Non-DSLR, Prosumer discussion. These Sony models all have Real Time LCD displays, and Real Time Electronic Viewfinders. When you compose with the real time LCD or EVF, the sensor is giving you a view of what it will capture in IR Light. This is a real advantage over the cameras which use Optical Viewfinders, where you can only see the scene in Normal Color Light. IR can make dramatic changes to the view you get of a scene. Seeing it in the IR Light that will be captured is a valuable advantage. Your composition of the scene may be greatly different when you see it in IR vs seeing it in Visible Color Light.

So everything is wonderful and perfect in IR Land right? Just get one of these Nightshot equipped cameras, and you have a perfect tool. By now you know better than that! There are always Cons. In this case, the crippling of the setting of Shutter and Aperture controls will at times have an adverse effect. No matter what you do to steady the camera, there are times when 1/60 or 1/30 sec. shutter speeds are just not going to give you the sharp well exposed image that you want. As for exposure, it is really up to you, and the only thing you can do is add or subtract ND filters. OK, you do still have control of EV adjustments, so you can fine tune your exposure with EV adjustments. As is true with any digital camera, Digital Noise can be a problem if your exposure is not right on. If, the exposure is on, you are fine, which in fact turns out that way most of the time, but occasionally improper exposure can ruin that image that you really wanted. One thing you can do to help control digital noise is to set the ISO to the lowest setting you can select on your camera, and be sure that you shoot in "P" (professional) mode, so that your ISO setting is used.

Happily, these some of these cameras also Mod well. Professional Mods to remove the IR Block Hot Mirror can, as with the modded DSLRs, give you full Shutter and Aperture setting control which will allow you to avoid exposure problems. The extremely sharp glass on each of these models make them really good candidates for modification if you want to take your IR experience all the way. Take a look at Niek's 717 mod steps to get an idea of what it takes to go into the guts of a 717 and remove the IR Block Hot Mirror.

Niek Haak's step by step pictorial

Use the Useful Links here on this site to find companies that professionally make IR mods to cameras. Give them a call to see if they can modify your camera model.



-=- Jerry -=-
.

10 comments:

Anonymous said...

I really hope that you can help me.

I have been searching for answers on the web and I found your blog.
A pervert took pictures of me using Sony Cyber Shot dsc-V1. I didn't know this camera was able to take x-ray pictures and it looked like a normal digital camera.Your entry says that night mode can be used by just flipping a switch, so I am really worried that he might have taken some x-ray pictures of me. I did a lot of research and noticed that in order to use the IR Pass Filter (52mm for dsc-v1?), a lens adapter tube (52mm?) has to be attached to the camera first. I remembered that there wasn't any external object attached to the camera when he took pictures of me. He had camera in his hand both indoor and outdoor. Indoor: it was a dim room and it was in the afternoon with the blinds closed. Outdoor: it was a sunny afternoon.

Can Sony Cyber Shot dsc-V1 take x-ray pictures without using lens adapter tube and/or IR Pass Filter using night mode? Is this camera powerful enough to take x-ray pictures on its own? Is there any mini filters/devices that could be added such that x-ray pictures were taken without doing too many extra moves (changing modes, adding/removing filters)?

Please help me and thank you in advance.

Infrared Photography Buzz said...

The photographer did not take X-Ray pictures of you. The Sony V1 is not capable of seeing thru clothes. This is much too hyped by companies wanting to sell filters claiming to make the camera an X-Ray camera. Doesn't work that way.

Some of the early owners of Sony Movie Cameras that had the Nightshot feature noticed that if a person was wearing certain man-made fabrics that do not reflect IR light, that clothing underneath that reflected IR very well would show up. The fabrics that "worked" were very thin, and you could probably see a bra for instance thru it anyway in regular light. If the fabric were wet and clingy, well, you can almost see thru that with your eyes anyway.

The whole thing was way over-blown, and Sony, to protect their reputation removed almost all camera setting ability in Nightshot still cameras. The V1 is one that Is "locked down" in Nightshot.

I have taken many photos of people with my Sony 717 (which has less restrictions in Nightshot than the V1). I also have a DSLR that is modified for IR, and has no restrictions at all. I have yet to have gotten any image taken in any kind of light where you could see thru the people's clothes.

I don't think you have anything to worry about.

-=- Jerry -=-
.

Anonymous said...

Thanks for answering my questions.

Gerald said...

Um...that wasn't a bit suspicious...

ir buzz said...

suspicious ,,,, maybe....
possible to get an IR naked picture thru clothing ....
I don't believe it.

Send me any IR image sample of something more than you could see in any supermarket check-out line in the summer time!

Anonymous said...

I was wondering if there were an example IR pictures that you had taken (in the daytime) with the H9 that perhaps you could post?
I am very interested in IR photography and am trying to find the best bridge camera to be able to do it. Thanks!

M said...

Great article and very informative.

I would like to ask the indoor effectiveness of IR photography. I am a concert photographer with the restrictions of flash photography, would a a converted DSLR would be as effective in an indoor environment.

Thanks
M

Anonymous said...

nice information... well i have a Sony DSC-H9 camera and a PF1 and PF4 filter of 54mm presented to me by a friend. pls dont misunderstand my question. out of curiosity what i am askign is that does it mean when i mount the PF1 or PF4 infront of my h9 cam with nightshot mode switched on brings a transparent image in daylight ??

Anonymous said...

Most ND filters are relatively transparent at IR wavelengths and so do little to cut the amount IR light down. In midday sunlight, an image produced using an IR filter and ND8 filter is usually still overexposed on the Sony F717.

Mark said...

I need to be able to take both IR and UV photos in the dark using IR or UV illumination only. I am a paranormal investigator and want to invest in the proper camera. Would the Sony 717 like you have be a good choice for this application? I'd like the camera to capture as much of the UV spectrum as possible also and it is my understanding that digital cameras are somewhat limited in this ability. Maybe you can shed some "light" on this. (Sorry, couldn't resist.) Thanks for your help.

Mark