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Nikon D300IR review

June 3, 2012

This review is about my "new" IR-modified Nikon D300. Thus, the main issue here is the IR capability of the D300, not the camera itself, which is well known.

Black hole. In front of the sensor there is a dark-looking longpass filter. That is the only difference between a D300IR and a non-modified D300.

I bought a used D300, tested it and sent it to Optic Makario (see links section) for the IR modifying. They removed the original IR blocking filter in front of the sensor and replaced it by a 700nm longpass filter. My D300 is a dedicated IR camera now, it is no longer usable for normal photography. I don't need a screw-in filter in front of the lens. The exposure values are similar to those in visible light, thus a tripod is not necessary.

Some basic information about infrared photography can be found in my article photography in invisible light.

This D300 is the third camera body Makario has modified for me. The quality of their work is very good and I never had problems with my modified bodies. The first modification was a non-defined D70, usually named D70UVIR. One year ago there came a D70IR and now the D300IR. Nevertheless I have to criticise Makario in one point:

Recalibration of the autofocus system for IR?

On their website, Optic Makario state that a recalibration of the AF system would be a part of their IR modification. This recalibration would be made by Makario's self developed procedure called "MWK" (I phoned them and they ensured me that they even had recalibrated my camera). Due to this calibration there should be no infrared focus shift when using the AF system. They don't speak about lenses in this context!

I cross-compared* the autofocus system of my D70IR with a non-modified D70 a few times and with different lenses (wide open, of course). The results were ever the same: the images of the IR-modified camera show the typical focus shift, but I could not detect a difference between the two images from the D70 or between the two images from the D70IR. That showed me that the AF-systems of the two cameras work identically!

*meaning to excute the following steps and after that to compare the two images of each pair:

After I received my converted D300, I cross-compared it with my D700 (both cameras share the same AF system) in the same way. The result was what I expected: no difference in the behaviour of the AF systems.

Optic Makario should not raise expectations which they cannot satisfy. Simply remove some statements from the website or describe the things a bit more detailed and everything is ok! The websites of American shops which offer IR conversions (see my "links" section) are better in this point. They are more cautious in praising their AF recalibration. For example, says they would calibrate a Nikon body by default with an AF-S Nikkor 18-70mm f/3.5-4.5 DX. That's funny, because this lens has the lowest focus shift among all the lenses I tried for IR. Therefore, a recalibration for this lens is nearly no recalibration. Maybe Makario use the same lens - that would be an explanation for my cross-compare results.

Why a D300?

I have always been satisfied with the infrared image quality of the D70IR. And the handling is just like photographing with a normal camera: the finder is bright and the shutter speeds are fast... but there is the focus shift problem. In some situations you can work around it, but for me, it was very often a limitation.

There are two improvements helping to mitigate the focus shift issue, which mainly influenced my decision for the D300:

Of course, the D300 has a lot of other advantages over the D70: better finder, much better monitor, faster, 14bit-RAW, exif data from non-CPU lenses, etc.. And for me as a D700 user there are further more: very similar handling, same battery grip, same memory cards.

Strange: white balance preset is not possible!

Seeing the world through rose-coloured glasses - JPG direct out of the camera, WB set to "sodium-vapor lamps".

The first thing I did with the D300IR was trying to make a WB preset pointing the camera down to the grass in my garden. But everything I saw in the display was "No Good". I tried a lot of exposure settings and different subjects to make a WB preset, without success. On the Web I found two reports about the same problem with a non-modified D300 with a screw-in longpass filter. I conclude that it is a typical problem for this camera. The D70IR doesn't have such a problem.

Of course, I can do the colour balance later in post-processing with Nikon Capture NX. But for my workflow, that often includes an early sort-out phase by viewing the JPEGs, an infrared WB is better. Setting the WB to "sodium-vapor lamps" with an additional "G6" helps to make it look a little bit like the real thing.

Surprise: the D300 is more sensitive for IR than the D70!

Don't get confused: an unmodified D300 is much less sensitive for infrared light UV than an unmodified D70. The reason is the much better IR blocking filter of the D300. But nevertheless I had expected the D70's sensor to be better here - the more this is a nice surprise! The difference between the two cameras is about a 2/3 f-stop.

Both images were taken with the same exposure and WB settings. The postprocessing in Capture NX was identical, too. The left one was taken with the D70IR, the right one with the D300IR.

If I use an additional 830nm screw-in longpass-filter, there is no significant difference in sensitivity between the two cameras. Thus, I conlude that the sensor of the D300 is more sensitive only in the nearest IR range (alternative, but in my eyes improbable explanation: Makario uses today a very different longpass filter in terms of transmission characteristics).

AF fine tuning

My current settings for AF fine tuning consist of only two values: a default value of -20 (which is the lowest possible value) and a value of -5 for the AF-S 18-70mm DX.

The 18-70mm works fine towards the long end with the value of -5. At 18mm it requires a value of 0, but stopped down to about F8 it even works in an acceptable way with a setting of -5.

My AF-S 300mm f/4 was already usable on the D70IR (and on the D70UVIR with a B+W 092) due to its only very slight infrared focus shift. On the D300IR this lens works nearly perfect in terms of focussing (with the default value of -20). As in visible light it is a great lens for photographing insects.

Procreation. Captured with the D300IR at ISO 200, AF-S Nikkor 300mm f/4 at F11, handheld at 1/250sec, phase-detection AF.

The rest of my AF lenses are not really usable on my D300IR in conjunction with phase-detection AF. The AF-S 17-35mm f/2.8, the plastic AF-S 18-55mm G II and the AF 180mm f/2.8 might be usable well stopped down at a pinch.

Overall, the situation for using the phase-detection AF on both the D70IR and the D300IR is similar with slight advantages for the D300IR due to its fine tuning opportunities. A more sophisticated fine tuning system would be great: the option to set correction values for different combinations of focal length (for zooms) and focus distance instead of only one value for the lens. And the range of the correction values should be greater. This is only software: Nikon, please give us an corresponding firmware update!

New opportunities for IR: live view tripod mode

I have never been a fan of live view photographing. I use this feature on my D700 only for very special shots. But on the IR-modified camera the contrast-detection autofocus enables exact focussing even with telephoto lenses at small aperture values and so on. Such things were impossible on the D70IR within a reasonable amount of time! Therefore live view tripod mode is my standard shooting mode on the D300IR, except for hand-held macro shots and for photographing with the AF-S 18-70mm DX or the AF-S 300mm f/4.

Don't worry about the word tripod. Most of the time I use this mode hand-held. My workflow with an AF lens is like this:

The ergonomics of the D300 is very good for that, during the last three steps you are able to hold the unit steady.

D300IR in live view mode.

With a manual focus lens the workflow is the same except for the third step: I magnify the screen just as much as necessary for evaluating sharpness and then I do the fine focussing by hand. Well, that's more complicated, because focussing in this way is a shaky thing and because you only see a magnified part of the image when you shoot.

One of the main problems of live view mode is working in bright light. Of course, you should set the display brightness to maximum. But what you see on the display is mostly pinkish and flat. Therefore it is sometimes difficult to perceive anything on the display. I tried a pop-up shade. That's fine on a tripod. But if I shoot hand-held in live view, the camera is about 10 to 20 cm below my eyelevel in order to have a steady hold. With the pop-up shade I can not see the upper part of the display... The last resort for me is to use a black T-shirt or something like that, just like the photographers 100 years ago used a black cloth.

I have another little problem with live view mode: I can't use it without wearing my reading glasses.

Nothing new: exposure metering

Invisible brightness in the dark forest: using the auto exposure mode.

The metering system of the D300IR is mostly useless. The metering results are valid for visible light, not for infrared light. No difference to the D70IR in this point. Even in live view mode the camera doesn't meter with the image sensor.

You can use the metering for getting a starting point and then correct it in a try and error process or you just work in manual mode. That depends on your personal taste.

I use the D300IR all the time set to 14-bit raw quality (plus additional JPEGs in basic quality). That gives me the opportunity to correct the exposure in Nikon Capture NX in a huge range. There is only one drawback about the 14-bit raws: the speed of continuous shooting is limited to 2 frames per second. Thus, if necessary, I go down to 12-bit raws.

Image quality

The D300IR is capable of delivering tremendous image quality:

Osteospermum ecklonis, captured with the D300IR at ISO 200, PC-E Micro-Nikkor 85mm f/2.8 at F8, hand-held at 1/640 sec.

100% crop of the above image.

The image quality of the D300IR is a bit better than that of the D70IR. But it is not a revolution, it is an evolutionary step.


It is a good idea to modify a D300 for infrared photography! The sensor is very sensitive for IR, the image quality is great and especially the live view mode opens new possibilities.

I tested a couple of lenses in conjunction with the D300IR, see my newly updated subjective lens evaluations. Further D300IR ratings will follow there.

Maybe one day there will be a mirrorless F-Mount camera with an EVF and metering via the image sensor. For me such a camera would not be of interest for visible light photography. But it would be a potential candidate for an IR modification!

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