Using a new lens I got for Christmas

Started by PZ, February 15, 2022, 08:20:14 PM

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PZ

Quote from: mandru on March 24, 2022, 10:28:42 AM
The reason I mention this is that I greatly enjoy the shared images you've photographed but also get the feeling that you sometimes entertain an out of the box approach to things.  I've noticed that some of the ghost towns and old factories that you like to visit might gain an alternate perspective from a bit of photography dabbling in Infrared (IR).  There's something about the alternate viewpoint of IR (B&W or Color) that adds other worldliness or the feeling of a haunting liminal space.

Older lenses such as this image shows have a feature for usage with Infrared photography:

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Example stolen randomly off the internet - I think it was an EBAY post

The physics of Infrared Light causes it to focus short of the of a camera's objective plane.  It's a fact that's true in either a film or digital camera.  Compensation for this is required to maintain crisp focus when shooting IR as shown by the Red Line on the lens above.

I don't know if your camera has this marked on the barrel of the lens or if your lens is purely automatic focus eliminating the manual focus markings which would render this post mostly useless other than giving me something to keep me occupied on a boring "nothing better to do" morning.  :evil2:

??? wow mandru, you know more about photography than I've even heard of! What you wrote about is the first I've heard (at least knowingly) of infrared photography in the way you describe, and it sounds fascinating.  :thumbsup:

My lens is capable of manual focus, but I do not know how it works internally because the lens does not shorten nor lengthen when manually focusing, and it does not feel like glass is moving within the barrel.  Below is a pic of my lens with a green arrow pointing to what appears to have something to do with focusing. Associated with that tiny window are also a couple of red lines that I know nothing about (but will investigate)

You're correct about me thinking inside the box at times - I've not done anything with manual focus because my eyesight is poor enough that I am relying on the auto-focus ability of the camera.

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mandru

With that photo I've been able to dig deeper.  The two red numbers each with a line leading up to the distance indicator (near the lens mount) are the IR calibration markings.

Page 12 section 8 of this PDF is the (CTRL-F searchable) manufacturer's instruction guide where it gives a small amount of info about IR when shooting with monochrome film:

https://www.bhphotovideo.com/lit_files/253677.pdf

Unfortunately as is usually the case my experience (from decades before the internet) has been that any printed information about shooting in IR is usually handled as something to be feared akin to alchemy or evil black sorcery.  :banghead:

The best I can make out from this PDF is that below the focal distance indicator there is a range between two Red IR calibration points.  If the image you are trying to take a picture of is less than 100 meters you would adjust the focus ring to the 100 setting and as distance increases you decrease in slight increments towards to 135 meter red distance index mark where you will have reached infinite focus and anything at that distance or further away will be sharply focused.  The old Kodak Instamatic cameras had a huge range that fell in the infinite focus because of their tiny lens aperture.

I don't know if the camera's internal digital Image Sensor will transmit light gathered through a Wratten #87 (or 87c for color) in IR to the color LCD view screen.  I would hope that you system would treat light as light and allow you to frame and focus in the LCD view screen.

Where my SLR was not digital I was shooting blind but I suspect with your camera's auto exposure you can bet that the correct amount of light will be gathered for the exposure.

Sorry I had to toss this off quickly as I need to get going   But I'm willing to try to field any questions I can if this interests you.

Maybe do a search for "color infrared photos" to get a taste of what's possible.
- mandru
Gramma said "Never turn your back 'till you've cut their heads off"

PZ

Thanks mandru!  :thumbsup:

Definitely gives me food for thought and exploration. Now I have a starting point from which to explore. I've always wondered what the little windows and colored lines were used for, but because the camera took okay pictures the way it is I guess I was just too lazy to dive into it, especially not knowing anything cool might result.

One thing though, I assume because of the reference to using film, this technique is to be used with a standard film SLR rather than a digital?

mandru

My thought is that depending on the megapixels of the camera's internal digital image sensor it actually can collect more information than film and should be more forgiving for experimentation.  I'm not fully familiar with the digital aspects of your camera and lens but I'd say allow the camera to auto focus on your subject, then switch to manual and fine tune using the IR compensation markers before shooting.

Once you've got the gear digital is a lot less expensive over film shot per shot.

Apparently the threaded mount on the front of your lens takes a 77mm filter something like a lens protecting UV haze or Polarized filter.  I've been searching online for the 87c Wratten that will fit the lens' threaded mount but I've not had much luck getting source to buy or a price.

That said some of the prices I've encountered for just the gel filters have jumped scary high since I was using them.  Honestly the now that I've tried looking into it the cost may be a deterrent for this line of exploration.  :o
- mandru
Gramma said "Never turn your back 'till you've cut their heads off"

Dweller_Benthos

A friend of mine does a lot of Infrared and Ultraviolet photography. He has thousands invested in cameras and filters, flash units, etc. From what I recall, most generic digital cameras these days are sensitive to some of the IR range and can be used with some success to create a sort of IR photograph. Again, pulling from memory, you have to use a very dark visible light blocking filter, and a very long exposure to get enough IR light to the sensor to make a successful exposure. This of course requires a tripod and a fairly stationary subject. If you want to pursue further, you can have a camera modified to remove the IR filter that is over the sensor and it will then be able to detect much more IR light. This of course makes it almost useless for normal photography in visible light as you will have all sorts of exposure problems and hot spots from the IR "light" overloading the sensor. So you have to use a set of filters, and in a lot of cases, long exposures, though not as long as on an unmodified camera, and then post-processing to make the image look like something. Usually, the images from the camera have a heavy magenta cast, which you have to process out to a final black and white image that has IR exposure.

You can see some of his IR shots here

http://www.herbchong.com/Photo%20Diary/2017/05-28%20OK%20Slip%20Falls/index.htm

That is OK Slip Falls in the Adirondacks and there are regular visible light shots and black and white IR converted shots for comparison. The white foliage is a giveaway that it's IR as leaves in sunlight reflect a lot of IR energy and expose pure white in a lot of cases. I don't think he has too much trouble with focusing in IR as the camera has live view on it and is sensitive enough to show you what's in focus and what's not. I'd have to ask him if he uses the IR indicator on the lens or just goes by what he sees on the viewscreen. Color IR photography is a bit more trouble, but still possible.

Now, Ultraviolet photography is another whole kettle of fish, though I think a camera sensor can be modified to "see" ultraviolet light, almost all lenses block most ultraviolet just by the characteristics of the glass itself. I'm pretty sure he has very specialized (read: expensive) lenses that are specially made to pass as much UV light as possible for just such an application. Normally, you don't want UV light in your visible light photographs as it causes weird effects and loss of contrast. Hence why "skylight" filters are popular, they block UV and some blue light to get more crisp images in visible light.

B&H Photo has pretty much anything photography related.

https://www.bhphotovideo.com/

Expect sticker shock lol.
"You've read it, you can't un-read it."
D_B

mandru

D_B you've added a lot of good information that I wasn't able to supply.  :)

Heh, it looks like I'm a bit out of my depth when it comes to digital cameras.  But I am wondering if PZ's camera has a setting for B&W shots that would w0#k with the standard Wratten #87 and skip the #87c.

A lot of the supposed color IR images I'm finding (when I look more closely) are actually color enhanced in Photoshop.
- mandru
Gramma said "Never turn your back 'till you've cut their heads off"

PZ

My camera dies not appear to have a b/w shooting mode. Although I'm not positive, one can use the RAW shooting mode and then use post processing to achieve whatever effects you want. I'm using the free Canon Digital Professional v4, and one of the "recipes" is to use the raw data to produce monochrome output.

I did some research in to my camera bodies, and it looks like people are doing what they call infrared conversions with their DSLRs. I'm still early in to the research but it looks like they are sending the cameras in to have a professional do a conversion, which evidently uses a 720n filter. The pics they are generating look spectacular!


Dweller_Benthos

Yeah an IR conversion usually requires removing or changing the filter that's over the sensor, and requires professional handling, not something you want to do at home. And as I said, it essentially makes the camera IR only after that, though I think you can use a combination of filters to bring it back to "normal" visible light photography. But if it's something you might want to get into, look at this video to get an explanation, it just happens to be the first one that came up in a google search and seems like it covers the topic well, I didn't watch all of it

"You've read it, you can't un-read it."
D_B

PZ

Thanks D_B  :thumbsup:

The author mentioned using a Hoya R72 filter which allows only IR light through. He suggested that it is a good way to become acquainted with that form of photography. Something to consider, I guess

Dweller_Benthos

Yeah I skipped through the video to see what he had to say, and using that filter is usually where people start with digital IR photography. It will give you an idea of what is possible and let you know what to expect without a huge outlay of money.
"You've read it, you can't un-read it."
D_B

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