Saturday, May 12, 2018

KAPSA RED DOT

This is a fun and very cheap box camera made in Brazil, between the '50s and '60s.

It's bakelite body is well made and follows the old box formula from the early '30s without any surprises or significant technological evolution. It was made to be cheap and usable.

Kapsa Red Dot

It has two waist level bright viewfinders, for landscape and portrait orientation, like many other symmilar ones. Those viewfinders are dreadful to use. 

The objective is a 110 mm two element achromat with a 3 position focus lever (1-2m , 2-8m and 8-infinity). The lens has a very primitive coating. When set at infinity the lens uses just the two main front elements, but when you set it for shorter ranges, a third element is put behind the shutter to set the focus point. Well, sort of...

The shutter is extremely crude. Just two settings: T and 1/100s and also three aperture settings: F8, F11 and F16. I would use it with ISO 100 color film or ISO 400 black and white film if you plan to use filters, like a Yellow or Green one. No idea of the filter size, but it's surely some sort of push on type.

It takes 120 film and can be used as 6x9 or 6x4.5 format. You can choose the format by flipping two metal masks.

Kapsa film chamber. Note the masks for 6x4.5 format

Well, don't expect a tack sharp image, of course !

Soft image, lots of chromatic aberration, rather low contrast, but fun to use. I bet it will give better images if used with black and white film.

Curious about the photos it can make ? Take a look !

Botanical Garden - Rio de Janeiro - Brazil
Camera: Kapsa Red Dot  Film: Fuji Xtra 400
Cheers !




Tuesday, May 1, 2018

Sigma Photo Pro 6.6

Hi there !

Sigma released the Sigma Photo Pro version 6.6.0 for Windows and Mac.

It was a much expected update due two new major (and essential) features we users were begging for years:

- A tone curve adjustment 

- An before / after comparing window

It was too good to be true. Sigma TOTALLY IGNORED a legion of pre Quattro camera owners, making the new curve control to work just with Quattro raw files.

There is absolutely no technical reason for this. I'm a software developer with 30 years on the road and trust me, this is simply ridiculous.

I'm totally frustrated with this and I will NOT even consider to buy any of the Quattro cameras unless they fix this.

Sigma is failing to understand that we need a professional grade software for ALL variations of X3F files. Please take a look a Canon's Digital Photo Professional and learn from it.

I hope that Mr. Kazuto Yamaki's father makes him a visit and teach him that abandon loyal supporters was not a nice thing.


Apple Photos (Still) Sucks

One of my biggest frustrations about software in the recent years was the Apple Photos, intended to be an iPhoto replacement.

Compared to iPhoto, there are some improvements. The user interface is cleaner and more fluid to use. 

Other adjustments and tools, like color presets, crop, rotate and retouch tool will make beginners happy, but they are very limited.

The only GOOD thing is that it allows the use of extensions (plug-ins) like Nik Collection for Photos and some other ones.

Photos also induces the user to keep everything on iCloud, something I really don't have love for. 

But Photos has some serious caveats in my opinion:

No Star Rating ! Apple says that now you have to do is to create keywords like "1star" , "2star" and so and use those keywords in the search field. Seriously ? Are you kidding  ?

No Flag, Color or Rejected ! Apple thinks that just a like is enough. This is stupid. 

Bad search tool, specially compared to Aperture's. The search is limited to keywords and dates. On the other hand, Aperture provides an extremely comprehensive search tool.

No more hierarchical keywords.

Can you use Apple Photos as a DAM ? Just if you don't have any other option or really don't want to try anything else.

You can organize in albuns, prepare photobooks, order printed photos and other simple tasks. 

In short, Apple Photos is fairly good just for organizing in a chronological (timeline) way cell phone photo collections.

If you need something good and free, you may try:

- Darktable (DAM , Raw converter and image editor)
- XnViewMP (DAM with basic image adjustments)

From High Sierra it adds some useful stuff to Photos, for example a basic curves adjustment and a slightly better tagging system. The good news is it can now call some useful external editors, like DxO and RawPower. Note that you have to update your OSX to at least 10.13 (High Sierra) to have the new features, what in my opinion is stupid. Steve Jobs would never agree with this policy.



Friday, April 13, 2018

Mamiya 645 1000S

Oh, the Mamiya 645 ! This is a very special camera, the best 6x4.5 medium format SLR considering the cost and the quality you receive back.

It's wonderfully crafted in a black painted metal chassis, covered with leatherette. It's not a mechanical camera, but commanded by an extremely reliable electronic circuit that controls the cloth curtain shutter, offering exposures from low as 8 seconds to 1/1000s.

Mamiya 645 1000S with CDS Prism Finder
Lenses form left to right: 80/4 Macro , 55/2.8 , 80/2.8 , 150/3.5

There's no light meter on the body and the film advance is done by an old fashion crank. Perfect.

It has a fair X-Sync flash speed of 1/60s, which is not bad for a medium format SLR camera.

Besides the obvious shutter button on top it also has a second one at the camera's front. Other controls are a depth of field view and a mirror lock up levers and a mechanical self timer.

Being electronic, it needs a battery. Thanks it's just a very common 4LR44 alkaline that lasts for ages, but do the right thing, take it out when not using the camera.

At the body's top there's a HUGE focusing screen. The basic one will depend on the camera batch. Mine came with a diagonal split plus a microprism collar. This screen is very bright and easy to use.

The basic model comes with a waist level finder, nothing more than a foldable light hood and a viewing magnifier with focus adjustment. There's also a wire frame "sports finder" for rough framing.

There are four more view finders for the 645:

  • Prism Finder - A plain pentaprism finder
  • CDS Finder - Same but with a CDS light meter (matching needle on the right side) 
  • AE Finder - With an aperture priority shutter command. It shows the shutter speed by a scale/needle at the top of the view finder frame. It uses the camera's battery.
  • PD Finder - It's like the CDS finder but uses 7 leds instead of the match needle.

The standard objective is a stunning Mamiya-Sekor 80mm F2.8, the "normal" for the 120 film format. It's superb.


It's usually complemented by a standard wide angle Mamiya-Sekor 55mm F2.8 (roughly equivalent of a 35mm lens on 35mm film size) and a standard tele, the Mamiya-Sekor 150mm F4. Both lenses are very sharp. I have the 3 lenses plus a 80mm F4 Macro.

There are plenty of other lenses, from fisheyes to long telephotos, macros, zooms and more.


To my own taste, this is by far the most cost effective 6x4.5 camera system.



Fujifilm X-TRANS RAW annoyances

This is not a review. Just some short comments about the most important programs that can handle X-Trans raw files.


Updated on October 11th, 2017

INTRODUCTION X-Trans raw files are a pain to process. Really.

The complicated nature of its non standard demosaic algorithms are a real nightmare for both users and developers. 

From the user side, there are just a few programs that are able to extract the full potential of this new class of color matrix, and all of them, besides the awfully complicated RawTherapee and Fuji's OEM version of Silkypix are paid and usually expensive.

Things aren't different from the developer's point of view. There are almost no technical information about the mathematical methods for the decoding process, and many of the amazing sharpen and noise reduction algorithms used be well known programs just can't cope with nothing else than the traditional Bayer pattern. That's why, for example, DxO just gave up on any non Bayer sensors.

These are my own opinions based on my experience and needs. Of course opinions can vary from people to people.



The most practical options on market due this day are:


IRIDIENT DEVELOPER

It's a very powerful software and probably the best one in terms of extracting the highest detail from the raw files. It's really good on this and also on noise reduction and film profiles. The price is fair.

The drawbacks are a horrible interface and it's slow. By horrible and slow I meant really horrible and slow. Its features are sometimes hidden in non obvious places and I never managed to find how to apply setting on a group of images in real time. I suggest you to try to do this.

But it's the best program if you want to have extremely detailed images from the X-Trans sensors.

Don't forget to download the film simulation profiles.

Pros: Generally very good results if you don't need to push too much sharpness.


Cons: Annoying interface and SLOW. Sometimes the sharpening adds funny artifacts that looks like noise.


FUJIFILM RAW FILE CONVERTER EX 2.0 (OEM SILKYPIX)

It's a stripped down Silkypix 4. It's free, so don't complain. =)

The interface is way better than the previous program but still have some serious problems with (maybe) the Japanese to English translation. Some terms are just too weird.

The overall results are acceptable but it's slow like hell. Can be upgraded to the last SP Pro version for $150. Not a cheap upgrade, but not awfully expensive.

Not recommended. It's slow like continental drift.


SILKYPIX 5,6,7,8

The 8 Pro is a solid program, but the full price is in my opinion too high, about $250. 

The good thing is that it has support for the camera's built-in film simulation profiles. The sharpen algorithms are very good and way better than the equivalents found on Photoshop, Lightroom and Capture One.

They offer upgrades for several OEM and previous versions for a reasonable price, from $250 to $100 in some cases. Worths checking.

After using SP 8 Pro for more than one month, I'm very impressed with the final result. The sharpen and noise reduction are maybe the best for X-Trans and the colors are far more accurate than any other competitors.

Pros: Generally good results IF you find out how to master the sharpen and noise reduction process. Image detail can be much better than Lightroom, Capture One and even Iridient, but you need to play with the sharpen controls to understand. I like the "Natural Sharp" option.

It's a very good idea to read the manual because many this aren't obvious on this program.

Cons: You really need to read the manual. There are lots of "hidden" important features.

Forget about any version lower than 7 Pro. 



RawTherapee

It's free, fast, well documented BUT it's by far the most complicated image processing program I've ever used in my life.

The sharpening and noise reduction functions are overwhelming and extremely comprehensive. Curves, color and histogram operations unfolds on many, many variations enough to make you scream when you see them for the first time.

The results can be awesome if you don't go nuts using it.

Pros: Can deliver stunning results and There are really good film simulation profiles for it.


Cons: Extremely complex and you need do be cross between a Zen monk and a Image Scientist to master it. Not kidding. 



CAPTURE ONE and LIGHTROOM

Well, they work but honestly their raw engines are not a match for neither one of the above mentioned programs and they are very expensive for what they are. You need to do a true olympic marathon in adjustments to get "near" the image output from the other ones, so I won't even comment them. I just gave up on them.

Capture one is a solid option, but a bit pointless for a X-Trans camera. It handles X-Trans files reasonably well, but there are better options for less than the $300 they ask for it. The only reason I can imagine to buy it is IF you're a very heavy C1 Media Pro user AND also use a Canon or Nikon camera in tethering mode, otherwise is a complete waste of money. I've tried it by 60 days in early 2018 and I was not convinced.

Lightroom is almost a religion, and forgive me fanboys, its X-Trans support still  sucks in plain 2018 and I would never, ever use a subscription based software. It will be a money sink in the long run, just do your calculations and check by yourself. It's evolving but there are better options.


AFFINITY PHOTO

This was a surprise. Its raw engine is still under development but I got some interesting results from it with x-trans files. I have to do some more experiments before giving it an honest rating.

There are many third party photoshop plug-ins that will run on Affinity. It's also compatible with Nik's collection.

Pros: It's FAST and good. Compatible with Nik collection, DxO Film Pack and Noiseware Professional plugins from Photoshop.

Cons: No film profiles


Apple Aperture

If you're an Apple user and still have Aperture installed and updated, incredibly, it is capable of very good results, pairing even with Iridient. Images tends to have less noise. You need to add the raw fine tuning  control.

The raw engine is OS dependent, so it will support all cameras supported by Apple Raw Engine. The updates are OS updates, not Aperture's.

For film simulation, I use DxO Film pack Aperture plugin. The response is a bit different than Silkypix's but I'm very pleased with it.

 


Pros: Very nice final look with good colors and well controlled sharpness. Compatible with Nik collection, DxO Film Pack and Noiseware Professional plugins for Aperture

Cons: Aperture reached end of life development. It still works on MacOS High Sierra but who knows the future. No film profiles.

If you're a Mac user, my advice is to keep it while you can and avoid updating the OS every time Apple tells you to do.

I have a spare bootable OSX High Sierra and Aperture on an external hard disk just in case.


RAW Power


If you have a Mac and like simple programs, RAW Power, from the former Aperture developer (the person himself) does a decent job. It's essentially a nice front end to the internal operational system raw engine from Apple.

Needs to evolve but it's cheap and honest and can be used as a Photos extension.

Desperately needs a file browser.

Luminar

Also a decent raw converter that can deal well with the tricky X-Trans files. I tested it on trial mode and I was quite pleased. No file browser.

Personally I think it needs to evolve, but surely worth a try. 

It's cheap, reasonably fast and runs on Mac and Windows.



Bottom Note:

In the end, after some years using the X Series, theX-Trans matrix doesn't appears to make any real improvement over a Bayer (without the AA filter) besides maybe some higher detail on high frequency zones. But the Fuji's package is very powerful considering the price and final result. Still a very good and solid option.

Fuji always liked to try some different approaches on sensor design, like the Super CCD and its numerous incarnations and I respect this. At least, like Sigma with the Foveon, they try.


Soon: Some examples using Iridient Developer, Silkypix, Capture One and Aperture. 

  

  

Why still use a 4.7 MP Foveon camera in 2016 ?

"Low Resolution" Foveon Cameras


From time to time someone asks me why I still use a 4.7 MP camera in today. People usually believe that the more resolution, the better the images are and this is not so simple.

Depending on the use we don't need a high resolution image. What you need is a proper pixel density to have a good viewing experience. What's this ?

For example, if you like to make printed photos, let's say, in postcard size (6x4 inches or 10x15 cm) you don't need many megapixels image to have a perfect looking print.

This is because the average human eye is virtually unable to see any difference in a printed (or projected) image at more than 300 dpi at a distance of 20 cm. This means that if you print the same image at the same size in 300 and 1000 dpi you simply won't be able to note any difference between them.

Let's do some simple calculations:

For a postcard size print, printed at 300 dpi we need (6 x 300) x (4 x 300) pixels = 1800 x 1200 pixels = 2160000 pixels = less than 2.2 megapixels.

For a larger A4 size (roughly 8.3 x 11.7 inches) we need 8.5 megapixels (8 will do fine)

To display a photo fullscreen on a DCI-4K UHD TV (4096x2160 pixels) we need 8 megapixels to fill all the screen pixels but depending on the viewing distance 4 or 5 megapixels would do fine.

Larger resolutions are good if you need to crop the image or if you're a pixel peeper and want to have some fun looking it at 1:1 size. For larger prints at 300 dpi, obviously you will need a higher resolution.

For poster size prints, you usually look at it from a distance and the print resolution can be lowered due the human vision nature. You can use an on line calculator to check what print resolution you need, based on the print size and viewing distance.

A very good one here
Another good tool is found here

In other words, you may not need the resolution you think.


Those old Sigma cameras, from the pre Merrill age like the SD14/15 and DP1/2 are more than enough if you don't need really large prints. Images form them can be easily interpolated by a 1.5 factor without any visible quality loss.

An interesting point of the Foveon images is the absence of color alias. It's possible to upscale the 4.7 MP image without any perceivable quality loss to 150% (linear) and with acceptable quality at 200%. The Sigma Photo Pro raw converter is very good for upsize.


The output resolution of those 4.7 MP cameras (DP1/2 and SD14/15) is 2652 x 1768 pixels.

Upsizing it to 150% lends to a 3978 x 2652 = 10.5 MP, more than enough for an A4 or Letter size print.


Just take a look at this image:



Sigma DP2 sample, from Sigma website
(C) Gris
and this other one:


Sigma DP2 sample, from Sigma website
(C) Gris

Go on... Use SPP to upsize them to 150% and print with a good paper, ink and printer and see by yourself.

Considering the fact that any of those Sigma cameras with 4.7 MP (x3) are very cheap now, it may worth a try.

Tuesday, March 13, 2018

Filters in Photography

Brief discussion about the most basic optical filters in conventional (film) and digital photography. There's a lot of misconceptions about their effects and finality of use by beginners and even more advanced users.

The goal here is to explain what are the UV blocking, contrast filters for black and white and color correction filters.

Other filters, like polarizers, gradients and other effect filters will not be covered here.


UV FILTER

Let's start by the simplest filter ever, the UV. It looks like a flat glass disk without any obvious feature, but as it name suggests it blocks, or at least attenuates, the amount of ultra violet light that reaches the film or sensor.

Film is sensitive to UV light and the excess of it can cause a bluish cast and haze on the photo. But why this ?

Let's talk about ultraviolet light. It's the light spectrum with wavelengths between 400nm and 100nm, being 400nm the very edge of the visible spectrum and 100nm a very penetrating and dangerous form of electromagnetic radiation. The Earth's blocks the shorter wavelengths more than the longer ones. 

To keep it simple, accept that the 100-300nm part will be totally blocked from space to the altitude of about 7km. Some of the 315nm may reach the lower altitudes (1500-2500m) and in some places even the surface, Longer ones will reach it, depending on the latitude, season, solar activity, pollution and other factors.

But what causes the bluish cast ? One of the causes are the very small dust particles in suspension. Small particles are able to reflect small wavelengths very efficiently, and thus, why they reflect more blue-violet than red light. That reflection makes the particles itself visible. Blocking the shorter light wavelengths will make the particles less visible, resulting in a clearer image.

Note that the particles also absorbs light from what's behind them, and this absorption will not be reduced or influenced by the UV filter.  

Films are sensitive in some degree to UV light and this is also an important issue.

Digital cameras are less prone to the problem but in a minor degree, they still are.

Camera sensors usually have a filter to block UV and IR (infrared) light and let pass the visible spectrum without being attenuated. This filter is technically a combination of a high pass and a low pass filters, resulting in a bandpass one.

But the filter cut-off limits aren't like a wall. It's a curve with a certain inclination.

Schneider B+W 010 UV Haze transmission curve
(C) Schneider Kreuznach 
The graphic above is the transmission curve of a typical good quality UV filter. The darker curve is for a multicoated filter. Note the higher transmission because of less loss of light due reflections.

The visible light window is, for practical information, between 400 and 700 nanometers. At about 800nm note that the filter also start to block infrared light.

This particular filter blocks 100% of the UV shorter than 350 nm but just 60% at 375 nm. This means that some UV will pass, depending on the wavelength. It's a more sophisticated filter, if compared with the standard UV filter.

There are other types of UV filters with slightly different curves:


UV filter family curves
(C) Hoya

But there are lots of makers and filters belonging to the UV family and quality varies a LOT depending on this. Some filters are flawless and other will degrade the image quality.

Keep in mind, for any filter type:

- Good filters aren't cheap but they don't degrade the image sharpness.

- A good anti reflection coating is a must. Ignoring this may result in undesired reflections and flare.

- Good UV filters have almost no light absorption.

- There are lots of counterfeit filters on the market., specially fake Hoyas. Be careful with eBay, Amazon and similar sources. If possible always buy from a trustable seller or store.


SKYLIGHT FILTER

First of all, a Skylight and UV filters are NOT the same thing. The main difference is the pinkish tint on the Skylight.

The Skylight filter blocks UV light but also attenuate a little the purple-blue part of the spectrum, resulting in a slight warmer image.


Skylight 1B filter curve
(C) Hoya

Both filters are extremely useful for film photography, specially for mountain/snow/beach areas.

There are different types of filters belonging to this family:

- SKY 1A
- SKY 1B
- Haze 

The difference between them is basically the intensity of the warming they add. Those filters are maybe the most widely used on film photography and have less impact on digital due the possibility of post processing.

On digital cameras with auto white balance set, the warm effect may be not present on the final image.


PROTECTION FILTERS

Those are supposed to be neutral filters, with no attenuation of the light spectrum and no color cast, at least on theory.

Again, a good coating is always a good idea and of course good filters come for a price.

They are excellent for lens protection against impacts and they saved me more than once. I remember some years ago, I was taking pictures at a mountain place and a small pebble came from somewhere and hit exactly the center of my Leica Apo Telyt and cracked a Hoya HMC Skylight filter. I was using a metal lens hood and it didn't make any difference. If the lens was hit, I'm pretty sure that it would be damaged.

It's also easier to clean a filter than a lens and if by some bad luck you scratched it, just buy another one.

In my view, good quality protection (or UV) filters are a must have. 



FILTERS FOR B&W PHOTOGRAPHY

Black and White FILM photography can be tricky if we're talking about contrast and tones.

It's easy to imagine a scene in plain colors, but not so easy to have a precise idea about the final look on black and white film.

B&W photography is all about contrast and tones and to make things worse, there are color tones that will be rendered exactly the same way on film, even being quite different colors.


There are four main filter types for B&W photography:

- Yellow
- Orange
- Red
- Green

There are other ones, like blue, lime, but let's talk about the four main ones for now.


Light Spectrum
    
Take a look at the spectrum image above and let's talk about the work horse of the b&w filters, the yellow one.


Transmission curves for filters (C) Hoya
Y2 = Yellow
YA3 = Orange
R1 = Red
X1 = Green
X0 = Lime

Filters like the yellow, orange and red are lowpass filters. They attenuates higher frequencies and let pass the lower ones with sight or no attenuation.

Take a look at the figure and let's talk about the transmission curve of a yellow (Y2) filter. The cut-off frequency of this filter is about 475nm. It will block all wavelengths below, let's say, 425nm. But the blue is at something like 470nm and will be just partially blocked. Looking at the graph I would guess that the blue light will be reduced by something like 10-15%.

This slight reduction on blue light can result in a slight contrast enhancement between a cloud and the blue sky. The sky will look a bit darker than the clouds.

The orange filter transmission curve "knee" is shifted to a longer wavelength, and will reduce dramatically violet, blue and some green.

And the red filter will cut from green to violet. 


A yellow filter makes colors with shorter wavelengths than yellow to appear darker than the longer wavelengths and all the longer wavelengths will have the same look as without the filter. The orange and the red ones follow the same rule .


Green filters have a different transmission curves. The Green (X1) is a band-pass filter, with the central point at something like 540 nanometers and it will attenuate any wavelengths in both directions but in a not so steep way.

Green filters makes green objects lighter (or brighter if you prefer) than objects of other colors. They're also nice for portraits of people with white skin, giving a more natural tone.

The lime filter is something like a combination of a band pass and a low pass filter, and can be used as a general purpose filter for b&w photography, if you plan to photograph people and vegetation.

The BLUE filter does the opposite of what the Red does. It will lighten the colors at the blue side of the spectrum and darken the ones at the red side. Blue filters are high-pass or band-pass filters, depending on the manufacturing process.

Important to mention is the fact all the above mentioned filters blocks 100% of the UV light.

FACTORS

All filters blocks some light and this quantity is called FILTER FACTOR. It's expressed in how many times the light will be attenuated. It's simple, if you're using a red filter it will reduce de light to 1/8 or -3 stops. Remember to compensate the exposure if you're not using TTL metering or if the filter is not covering the light sensor of your camera.


B&W Filter effect table

The skylight filter is like the Y1 filter, but for color photography.

Do NOT use physical Y/R/O/G filters on digital cameras with Bayer or X-Trans sensors, even if the camera is set to monochrome. This WILL cause interpolation errors during the demosaic process and may give very strange results. In this case you need to use software based filters.

But if you have a Sigma camera with the Foveon sensor or a Leica Monochrom and plan to shoot in b&w, you need the filters, like you were using b&w film. By the way, Foveon's pictures shot this way are amazing. 


Original image in color
Yellow filter, slight blue attenuation
Orange filter
Red filter
Green filter
Blue filter, severe yellow to red attenuation

Another set with more green.


Color, no filter
B&N no filter
Yellow
Orange
Red
Green
Blue


FILTERS FOR COLOR PHOTOGRAPHY


As a motto, you really want a Skylight filter attached to your lens for normal photography. But sometimes we need to use a color correction filter.


Color Warming filters

The #81 family cuts off the UV light and attenuates the bluish part of the spectrum in a way that contrary to the Y/O/R filters used in BV, would not totally mess up with the colors. The result will be a "warmer" light in the whole image, looking like the spectrum was shifted to the longest wavelenghts. But since it's a subtrative process, this not actually happens.


(C) Hoya

There are three 81 filters in different intensities:


  • 81A (1.2x factor, 3400K to 3200k, minus 200K)
  • 81B (1.3x factor, 3500k to 3200K, minus 300K)
  • 81C (1.4x factor, 3600K to 3200K, minus 400K)

A stronger effect can be obtained using a #85 filter.


(C) Hoya

  • 85A (2.0x factor, 5500K to 3400K)
  • 85B (1.6x factor, 5500K to 3200K)
  • 85C (1.8x factor, 5500K to 3800K)

The #85 series can be used to balance tungsten light film to be used on daylight conditions.


Opposite to the warming filters are the cooling ones. There are two main groups:

The #82 family is the opposite analog of the #81 family (sort off). They cool down the color temperature by absorbing the longer wavelenghts.
Like the previous mentioned warming filters, they come in three strengths 82A, 82B and 82C

They looks like pale blue filters. Below, the transmission curves of the #82 family. Note the opposition to the warming filters.


(C) Hoya

The #80 family is mostly used when someone need to use a daylight balanced film under tungsten light. They also come like 80A, 80B and 80C. They are deep blue filters.


(C) Hoya


  • 82A (1.3x factor, 3000K to 3200K)
  • 82B (1.5x factor, 2900K to 3200K)
  • 82C (1.6x factor, 2800K to 3200K)
  • 80A (4.0x factor, 3200K to 5500K)
  • 80B (3.0x factor, 3400K to 5500K)
  • 80C (2.0x factor, 3800K to 5500K)

There are many other special purpose filters, like neutral density, gradient, color enhancers and a myriad of special effect ones, like stars, diffusers, soft focus, diffraction, vignetting and more.

In a near future, I'll be discussing about ND, polarizers and gradients, but not the other ones.

NEUTRAL DENSITY FILTERS

Also known as ND filters, they are made to reduce the light by a known factor. Usually they are marked in a very easy way, just a ND followed by the factor, like ND-2, ND-4, ND-8, and so on.

A ND-2 will cut the light to a half (or 1 point), a ND-4 to a quarter (or 2 points), etc.

So, why would someone need less light ? There are so many reasons like the following:


  • A camera having a "slow" maximum shutter speed and using high ISO film, like a Konica Hexar Silver with an 800 ISO film in daylight because the maximum shutter speed for this camera is 1/250s
  • To allow the use of large apertures in high light conditions
  • To allow the use of slow shutter speeds in high light conditions, like to create the "water blur" effect.

ND factors can be very high. There are also variable ND filters, made by the combination of two polarizers. Personally I don't like the variable ones because some times you don't want any polarizing effect at all.

ND filters are useful in both film and digital photography. There are hundreds, even thousands of tutorials about ND filters on the Internet.