All posts in Infrared

02 Sep

Getting the Most Out of the NEX-5

In Infrared,Reviews by Greg / September 2, 2011 / 0 Comments

When the NEX cameras were first announced in May 2010 by Sony, many people were surprised by how small they were. At the time (and I believe this is still true) they were the smallest APSC sensor cameras ever made. This was a really big break through. I was very interested in the cameras for other reasons entirely –

1. I knew these would make great candidates for infrared conversion. Why? See my previous post here for more info.

2. It would not be possible to make better use of old obsolete lenses. If you say it was already possible to adapt lenses to the m43’s cameras, I would have to agree, but the advantage to the NEX is getting closer to using the full coverage of the lens. Instead of having a 2x crop factor on the m43 would only have a 1.5x crop factor, which as a DSLR shooter I am already very comfortable with.

The small size of the NEX-5 turned out to be more of a hindrance (thank you Sony for listening and creating the incredible NEX-7) than a help for me. I was excited 3rd parties out there like Ownuser and LCDVF came to the rescue. The Ownuser battery grip (I will do a write up on this grip in a later post) really makes the camera easier to hold. The LCDVF helps by giving you a giant viewfinder to look into the NEX’s LCD display, it also lets you use the camera eye level propped against your head, which can help you get a DSLR perspective and help with stabilizing the camera in low light situations. I hope to do more in-depth write-ups on these different products in a future posting. For now, suffice to say that the NEX can be useful a lot more like a “normal” DSLR but with all the advantages I was looking for that a mirrorless offers. Oh, and it looks really cool too:

NEX-5 Decked Out

02 Sep

Infrared Controlled Lighting

In Infrared,Technical by Greg / September 2, 2011 / 0 Comments

One thing I have been researching and practicing is strobe lighting (and continuous lighting as well) for use with infrared studio photography. I have not done a tone of actual shooting, but the first thing I have noticed so far is that light fall of is much sharper when using ordinary flashes for IR studio shots. The flashes themselves output a surprising amount of IR light, but their coverage is a lot more narrow. I dont really know what causes this yet, but will continue to experiment and learn what I can.

I think Minolta Rokkor lenses look really cool in IR because they have a silvery look, the two photos below were both taken with an infrared converted NEX-5 using a Rokkor 35mm lens. Both shots required quite a bit of post processing to get them to look reasonably nice, this was mostly due to the heavy light fall off toward the edges of where the flash was pointed.

Rokkor 8mm in IR

Rokkor MCs

27 Aug

Focus adjusting adapters for infrared

In Infrared,Mods,Technical by Greg / August 27, 2011 / 0 Comments

The issue with some lenses and infrared is that they will not properly focus at some or all focal lengths in infrared, because the focuser just doesnt go far enough. This is because infrared light always focuses slightly behind visible light (ie if you focus for visible light, the IR light will be focused behind the camera sensor). Most lenses still have enough room in their focus range to allow proper focusing in IR, but others do not. I noticed this was an issue first with my Rokinon 8mm fisheye so I started looking for ways to address it.

I borrowed the idea from Pete Ganzel who makes a conversion kit to convert Rokkor mount 58/1.2 lenses to A-mount. In the conversion kit from Pete are a small assortment of spacers which you will need to test to find the proper spacing of the replacement a-mount ring so you can properly focus. Well I applied the same principle to an aftermarket a-mount to e-mount adapter (this probably would not be a good idea to try with the LA-EA1 because of the electrical contacts, and not wanting to destroy a much more expensive adapter, of course).

So here is what I did:

First I removed the A-mount ring from this adapter, and then added some spacers where the screws mount to the ring. These are just test spacers which will get replaced with complete rings once I have time to make them, it was just easier to cut small strips for testing. There is no set rule to how much space youll need to add, try adding one spacers, put the assembly back together and test the lens you are having trouble with. If you really want to get it perfect you can keep trying until the distance markings on the focus ring line up perfectly when focused in IR.

adding spacers

The other thing to keep in mind is that the manual aperture lever in the adapter (if it has one) still works, since adding spacers may prevent it from reaching the lenses aperture lever. Also, you will want to check that the lens locking pin will still lock, I added a small screw to act as a spacer behind the spring which provides pressure to the lock pin to hold it in place when the lens is mounted. You will have to do trial an error to get these things right, and not all third party adapters will lens themselves well to this adjustment process.

Here is what mine ended up looking like with the test spacers in place:
spacers added

And here is what the adapter looks look on my IR converted NEX-5, with Minolta 28-135 mounted:
lens mounted

Lastly, the result? I can now properly focus the Minolta 28-135 and Rokinon 8mm in infrared, this shot below is with the Minolta at 28mm:
ir test shot

07 Jan

Sony cameras and infrared

In Infrared by Greg / January 7, 2011 / 4 Comments

While I never shot infrared in the film days, I know that with any camera it was possible to get started shooting infrared just as simply as buying infrared film and an IR filter. With digital things have changed a bit, while most digital sensors are perfectly suited to capturing infrared light, there is very little support for it from camera manufacturers. Nearly all digital cameras have powerful IR-blocking filters installed over the imaging sensor preventing IR photography with anything other than very long exposures. Sure, Sony has the Nightshot mode, but daytime IR photography is at best very difficult and the results are really quite limited as its real purpose is shooting at night, and then there were a few offerings from Fuji which never seemed to take off. Infrared is definitely a niche and perhaps the fact that only a relative few are into it is for the best.

So then, what do you need to get started in infrared? The short answer is any digital camera – since nearly all digital sensors are very sensitive to IR light, even with the blocking filters most of them have, its still possible with 30 second exposures to get started. If you are really serious about infrared, then a converted digital camera is the way to go. There are currently a handful of companies offering infrared conversions which I will talk more about in a later post. What I do want to point out now are features that make particular cameras better candidates for IR conversion – there are only two features I consider “must have”:

1. Custom White Balance – because IR cameras are essentially responding to infrared light and creating visible light images, it is necessary to use a pretty extreme white balance if you are interested in doing false color infrared. Note that the camera should have both a custom WB feature which attempts to automatically set the WB as well as a manual white balance. If your only interest is in black and white infrared, then this feature is unnecessary. Without a custom white balance feature it is typically near impossible to achieve an acceptable IR white balance.

2. RAW file support – in order to get the most from your custom white balanced files it really helps to have a camera that supports RAW. As a personal rule I shoot all photos in RAW, be it “normal color” or infrared, because it allows me to get the most out of every picture, this is a preference that I know some will disagree with. For infrared its mostly the same rule, it also allows me to create custom color profiles to use with Adobe Camera Raw allowing even better false colors IR.

In addition, there are some features that while non-essential can certainly make things a lot easier:
1. Main sensor live view – this allows you to compose the image exactly as the camera sees it, so you can adjust white balance as well as judge the exposure without taking a shot first.

2. Main sensor manual focus check – this is a feature where the camera can enlarge a live view image in the LCD so that you can verify the focus is correct. It is important that the camera uses its primary image sensor for live view (example – Sony a550/a580) as some cameras have a dedicated live view sensor (example – Sony a350). The reason is that IR light focuses differently than visible light and in a converted camera the infrared pass filter is installed over the sensor where the IR-blocking filter was.

3. Main sensor Contrast Autofocus – this allows the primary sensor to autofocus making accurate AF possible with nearly any AF lens and focal length. The main disadvantage is that Contrast AF is not as fast as the traditional Phase Detect AF used on nearly all DSLR’s.

4. Mirrorless cameras – while this is more an entire class of cameras rather than a feature, I consider these an advantage for IR photography. Since the OVF of a traditionally DSLR cannot offer much help other than composing the photo in visible light, in addition the phase detect AF sensors cannot accurately autofocus in IR, it’s best just to get rid of these items. Mirrorless cameras lack these things making them smaller and lighter – in addition to being able to adapt a huge range of lenses for other camera mounts.

Since I am a Sony user, I will provide a short list of features offered in current camera models that are helpful to IR. Note that I do not recommend any current model of Cybershot camera as none of them offer a manual custom white balance or RAW support (eventually I may do another post on Cybershot models for infrared). All current Sony NEX and Alpha’s offer both manual custom white balance and RAW support.

a500/a550:
-Main sensor live view – allows manual focus and composition in IR through LCD

a560/a580
-Main sensor live view – allows manual focus and composition in IR through LCD
-Main sensor contrast AF – means AF is possible with a-mount lenses

NEX3/NEX5
-Main sensor live view – allows manual focus and composition in IR through LCD
-Main sensor contrast AF – means AF is possible with e-mount and SAM/SSM a-mount lenses using the LA-EA1 adapter
-Can adapt a huge range of other lenses with third party adapters
-OVF is removed which is an advantage for IR since it isn’t very useful

This is not to say other cameras offered by Sony cannot be used for IR, the features and cameras listed above are specifically beneficial to infrared photography. My first DSLR converted was a Sony a350 and it has performed excellently as an infrared camera. My second is a mirrorless Sony NEX-5 and I have yet to take pictures that I feel are really better than my a350, its mainly just an easier camera to use with infrared for the reason’s listed above. Plus, it takes up a lot less room in my camera bag which is a great.

As a final note, you may also be wondering about the new SLT (a33 and a55 models) technology from Sony. At this time no one to my knowledge has converted an SLT for infrared photography. My concern would be that the fixed mirror may not respond favorably to infrared light, it may block light or add glare to every image. Features wise the a55 does not offer any advantage for IR over its a580 counterpart, in fact it is less useful because it lacks the Contrast based AF. I would shy away from SLT’s for infrared work, though I do use an a55 for regular photography and it is an excellent everyday camera.