Author Topic: I’d like to get started in UV/ IR  (Read 8021 times)

ArthurDent

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I’d like to get started in UV/ IR
« on: May 05, 2018, 04:14:59 »
and I haven’t a clue as to what to buy, or where to start. Any suggestions as to a good body to get modified, a vendor to do the modifications and some good, yet inexpensive, lenses would be greatly appreciated. I’d also appreciate some suggestions as to reading to get me up to speed quickly. Thanks for any help.

Øivind Tøien

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Re: I’d like to get started in UV/ IR
« Reply #1 on: May 05, 2018, 05:09:43 »
The Ultraviolet Photography Forum is the place to go, lots of information if you look around: http://www.ultravioletphotography.com

Be aware that reflected near visual IR photography is much less complicated equipment wise than reflected UV, which can become pretty costly, especially with respect to lenses (although there are less optimal less expensive alternatives) and filters.

Then there is UV induced visual fluorescence (UVIVF), which can be a lot of fun and does not even require a converted body. One need UV protective glasses, a UV source - preferably a UV LED flashlight, A UV high pass filter on the flashlight and perhaps a UV cut filter on the lens and it has to be performed at a dark location - exposure times are typically in the 5-20 sec range.

If you do not have an old body to convert to a dedicated IR body, then for instance a refurb or used  D5300 could be a good starting point with a Lifepixel standard IR modification, which is an IR pass filter with about 720 nm 50% cutoff. (D5300 is also a popular astro camera due to it's sensor).  I am personally using a Lifepixel modified D40x which works very well in IR although it has a pretty old sensor. There is also the possibility of a wide band conversion (clear glass replacing the UVIR cut filter in the body), but then filters for the lens comes in addition. Some lenses might have more problems with a front fitted IR filter than a modification of the body where the IR pass filter replaces the UV-IR cut filter.

IR compatibility of lenses can depend on the body combination. Thus the best is to just try what one has after acquiring an IR capable body and then go from there to see if there is need for other lenses. For instance I find that just about all my lenses in regular use works well in IR.
Øivind Tøien

Akira

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Re: I’d like to get started in UV/ IR
« Reply #2 on: May 05, 2018, 07:45:21 »
Arthur, as Øivind suggested, UV, iR and UVIVF are very different areas of photography.  So, it is essential to decide which kind of images you want to make in the first place.  The necessary equipments are also very different.

If you just want to get the feel of IR photography, the cheapest way should be to get a body with the inefficient IR-cut filter (D70, D70s or D40.  D2H is also good, but more expensive), because you don't need to modify, and an IR-pass filter (which cuts off at 720nm or denser).  Some lenses you already have may work well enough.  If none of your lenses would work, get an MF Nikkor 28/3.5 (either single- or multi-coated or K or Ai will do).  You also need a tripod, but you should already have one.

UV photography is a totally different league.  That said, D40 can be used for UV without modification, so it can serve you a very nice body to start that is very kind to your wallet.
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ArthurDent

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Re: I’d like to get started in UV/ IR
« Reply #3 on: May 05, 2018, 21:31:49 »
Oivind and Akira-Thank you for your very useful replies. I’ve done some online reading and this guy:
https://www.photoartfromscience.com/single-post/2017/04/21/Infrared-Photography-and-the-Nikon-D500
seems to think the D500 will work well in infrared, so I think I’ll buy a set of infrared filters and see which ones work best on the camera before I do anything else. Thank you again for your replies, very helpful in clarifying my thinking.

Akira

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Re: I’d like to get started in UV/ IR
« Reply #4 on: May 05, 2018, 22:58:05 »
Arthur, thank you for the link.

I was surprised to see such newer models seemed to have usable sensitivity to IR without modification.  But another article linked in the one you shared (titled "D610 VS. D7100 VS. D7000 Infrared Comparisons") says that they have the IR sensitivity only on the red channel.  That means that, as stated in the article, you only have a 1/4 of the resolution, and the diagonal lines would look jaggy due to the fact that the Bayer demosaicing algorithm is confused.

The older cameras I mentioned (D70, D2H or D40) are sensitive to IR in all R, G and B channels without modification.  So, the demosaicing algorithm works properly, and using very dense IR filters like IR84 or even IR90, you can have beautiful monochrome IR image of good quality.

However, if D500 can provide images posted in the linked article, you should be able to get the feel of IR photography at the cost of the filter, I won't tell you to stop experimenting.

Hope you enjoy it!
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Øivind Tøien

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Re: I’d like to get started in UV/ IR
« Reply #5 on: May 05, 2018, 23:37:45 »
Oivind and Akira-Thank you for your very useful replies. I’ve done some online reading and this guy:
https://www.photoartfromscience.com/single-post/2017/04/21/Infrared-Photography-and-the-Nikon-D500
seems to think the D500 will work well in infrared, so I think I’ll buy a set of infrared filters and see which ones work best on the camera before I do anything else. Thank you again for your replies, very helpful in clarifying my thinking.

Take a look at the exposure times : "My open-shade shots are made in the vicinity of ISO 100, f/8, 30 seconds."
This is crazy long. With an IR converted body normal exposure times are common, and normal metering can be used as starting point.
Thus the article's claim that "the D500, on the other hand, is excellent shooting infrared" is very far from correct if you consider the unmodified sensor's sensitivity. If you look at the link to D7000 which he also think is performing well, the example is a 15s exposure. A lot of the response seen might be in the IR spectrum near red (around the 720nm transition) and might not go deeper into infrared (response of an unfiltered sensor will go up to or beyond 1000 nm).

If you look at my post down the page here, http://nikongear.net/revival/index.php/topic,7403.msg119847.html#msg119847, the exposure for these shots were 1/400 and 1/30s, both at f/4 and ISO 100 (Keep in mind that one of them was an evening capture in late October after sunset). 

Of course nothing wrong with experimenting if the IR pass filter does not cost you much, but do not expect anything near the fun you can have with a dedicated IR body, or a wideband converted body with an external IR pass filter.
Øivind Tøien

ArthurDent

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Re: I’d like to get started in UV/ IR
« Reply #6 on: May 05, 2018, 23:40:18 »
Akira- Thanks for your reply. Do you have any thoughts on which ir filter is likely to work best? The R72 seems to be the most popular choice.

ArthurDent

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Re: I’d like to get started in UV/ IR
« Reply #7 on: May 05, 2018, 23:46:16 »
Oivind- Thank you for noting the distinction. I found an excellent condition D40 for ~$100,  not sure what the conversion cost would be, but even at $300, I wouldn’t have much into it. If I get a camera converted to ir, do I still need to use a filter?

Seapy

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Re: I’d like to get started in UV/ IR
« Reply #8 on: May 06, 2018, 00:02:57 »
If I get a camera converted to ir, do I still need to use a filter?

No, provided the conversion consists of replacing the standard Low Pass Filter (LPF) with an IR filter of your choice, usually 720nm.

I have a converted D200 and a second D200 with the LPF replaced by a plain glass window, is suitable for full spectrum from UV to IR with the appropriate filter to define the desired spectrum range. My main motive being 365nm UV with a 365nm band pass filter.
Robert C. P.
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Akira

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Re: I’d like to get started in UV/ IR
« Reply #9 on: May 06, 2018, 00:15:46 »
Akira- Thanks for your reply. Do you have any thoughts on which ir filter is likely to work best? The R72 seems to be the most popular choice.

Arthur, if you just try IR with your unmodified D500, you should go for R72.  R72 is a fairly light filter with some visible deep red leak, and, when you get a modified camera, it can be used for the IR false color image.  Any denser filter won't work (or result in an unacceptably long exposure time).

Here is an example shot with a stock D40 with a very dense IR90 filter (no visible light leak) at ISO400, 10sec.  The lens was Nikkor-H C 28/3.5 at, if I remember correctly, f8.0.  The second one is a straight-out-of-camera image (the original file is NEF and is converted and resized to jpeg without any edit).

The second image look pink due to the slightly more data in the red channel, but both the blue and the green channels offers healthy amount of data for good image quality.

Bare in mind that the focusing in the optical viewfinder is tricky, because you have to compensate for the focus shift.  That's why older MF lenses has "R" or red dots on the distant scales.  With R72 filter, the red dot can be fairly reliable, but with a denser filter, you have to compensate more.   If you do convert a camera, I would suggest choosing newer bodies with the live view capability, because you can focus on the LCD watching the real "IR" image without compensation.
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Øivind Tøien

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Re: I’d like to get started in UV/ IR
« Reply #10 on: May 06, 2018, 00:17:50 »
Oivind- Thank you for noting the distinction. I found an excellent condition D40 for ~$100,  not sure what the conversion cost would be, but even at $300, I wouldn’t have much into it. If I get a camera converted to ir, do I still need to use a filter?

The conversion of a body to dedicated IR implies that the internal IV/IR block filter is removed and replaced with an IR pass filter, so no external IR pass filter is needed. Only a wideband converted body (internal UVIR block filter replaced with protective glass) would need an external filter. An IR conversion with a filter cutoff at about 720 nm (for instance the Lifepixel standard conversion) or use of an external R72 filter (same cutoff) on a wide band converted body  is a good compromise between getting fairly good IR selectivity while still able to get some colors out of it.


However if spending on conversion I would go for a newer body than the 6 Mpix D40 sensor. I think that what Akira pointed out is that D40 does not have as effective UVIR cut filter as newer bodies, so it is good to be experimented with as is with an external filter.  Note that D40x has a completely different sensor that would need conversion for good IR sensitivity. Although I love the adorable D40x, if I personally was going to spend $275+ on a conversion today, I would likely go for a Nikon factory refurbished D5300 which can be had for as low as $420 now.  (I am actually slightly tempted at picking one up for astrophoto use). A nice thing about that body is that it is supported by CNX2. I would stay away from D5200 and D7100 as conversion candidates due to fixed pattern noise at low ISO when shades are pulled a lot, unless positive hands on experience with these bodies become available. The structure of noise can be important in IR due to frequent extreme contrast and color stretching. D5100 could another possible candidate, the noise pattern on my unconverted body is pretty random.

(Edited in parallel with the previous two messages).

Added: One thing to also consider is how the custom white balance works with a specific body in IR. (Daylight WB will render a very red image which is hard to evaluate when reviewing the image on the camera). That is one thing I like with my with D40x, it is very tolerant and will do this well with IR captures. I am not sure about D5300 in this respect (Lifepixel lists some reservations, depending on which filter is used). Perhaps someone who had it converted to an IR body (Bjørn/Birna?) can contribute. Even if custom WB does not work in-camera, if the body is supported by CNX2, the captures will white balance in post if desired.
Øivind Tøien

Akira

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Re: I’d like to get started in UV/ IR
« Reply #11 on: May 06, 2018, 00:33:13 »
However if spending on conversion I would go for a newer body than the 6 Mpix D40 sensor. I think that what Akira pointed out is that D40 does not has as effective UVIR cut filter as newer bodies, so it good to be experimented with as is with an external filter.

That's right.  The charm of D40 is that you can experiment with both IR and UV without modification "thanks to" its inefficient UV/IR block filter and relatively lower noise performance at that period of time.

These are examples of the UV image shot with, again, unmodified D40.  The crucifer is an excellent test subject to test the UV capability of your rig.  The first one is a B&W conversion, and the second shows how the SOOC file looks like.
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Hugh_3170

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Re: I’d like to get started in UV/ IR
« Reply #12 on: May 06, 2018, 09:45:38 »
As well as the D40, the Nikon D50/D70/D70S trio of cameras also had fairly inefficient low pass filters, so one of these three old timers with external filters can also be used to get an initial feel for whether or not UV or IR photography is for you without laying out money on converting a camera.

On the other hand, and at the other end of the commitment scale, Bob Friedman is now having D800 cameras converted with great results..........
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charlie

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Re: I’d like to get started in UV/ IR
« Reply #13 on: May 06, 2018, 22:46:45 »
There are some inexpensive lenses you can use to shoot UV, they won't get you the same results as the dedicated UV lenses of course but they can get you in the door, so to speak. They include the Nikkor-Q 200/f4, older metal barrel el-nikkor enlarger lenses (63mm and up should be able to reach infinity focus), and the 28mm/f2.8 series E lens (perhaps other E series lenses as well?).

I'm sure others here have suggestions as well.

Akira

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Re: I’d like to get started in UV/ IR
« Reply #14 on: May 07, 2018, 02:33:48 »
There are some inexpensive lenses you can use to shoot UV, they won't get you the same results as the dedicated UV lenses of course but they can get you in the door, so to speak. They include the Nikkor-Q 200/f4, older metal barrel el-nikkor enlarger lenses (63mm and up should be able to reach infinity focus), and the 28mm/f2.8 series E lens (perhaps other E series lenses as well?).

I'm sure others here have suggestions as well.

Among the series E, I also used 35/2.5 with reasonable results.

I used EL-Nikkors 50/2.8 and 75/4.0 (both the latest versions, multi-coated) as well as 50/2.8, 80/5.6 and 105/5.6 (all older versions, single coated).  The best ones among them are the older 80/5.6 and 105/5.6.  Their transmission of UV range is quite usable, and they are virtually focus-shift-free.  The latter characteristic is not crucial if the camera offers the live view mode and can focus in UV.  But it helps a lot if you use older digitals without live view.

Both the older 80 and 105 EL-Nikkors are easily discernible with their chrome coated mounting basis.  On thing to make sure is that the chrome basis is made from two parts, and the L39 mount part can be screwed off.  So, you should make sure that the lens comes with the L39 mount part.

A problem to note, though, is that both 80 and 105 lenses have rather odd 34.5mm filter thread.  It is tricky (although duable) to find the way to mount an UV-pass filter.
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