DIY 8mm Telecine – Progress Report 4

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Finally – here is the much overdue update I promised a while back! Progress has been made on several fronts since the last post: the projector now has an appropriate backlight, I drilled a hole in the backplate I made to allow for projection, a new lens has joined the lineup, and an Arduino UNO has been thrown in the mix!

Backlight

RGB_Backlight_OnThe backlight is a 3 watt, Red, Green, Blue (RGB) LED I purchased on eBay. The idea is that the red, green, and blue colors can be mixed independently to set the white balance and supposedly, an RGB LED will provide a fuller color spectrum as compared to a standard white LED. This is important for capturing all the different colors present in the original film.

Arduino

Arduino_Backlight_Control

The Arduino has been added mostly because I had eBay bucks to spend making the $12.79 Arduino essentially free.  While slower than the Propellor, the Arduino is easier to program (for me anyway). It supports hardware pulse width modulation (PWM) which I attempted to use to control the red, green, and blue channels of the LED (we’ll get to that…). As the Arduino is limited in how much output it can drive directly, I have the rather power LED powered through the transistors seen on the breadboard.

So why am I not using the Arduino’s hardware PWM controller to drive the LED channels? It turns out that the frequency the PWM controller operates at causes visual artifacts on the webcam. Cheap digital cameras scan their sensors sequentially – imagine the pixels on the sensor as being arranged into columns and rows. The sensor will start in the begin to scan the pixels in rows from top to bottom which takes a small amount of time. This is generally imperceptible, but when the image is changing quickly, it is possibly for the position of a picture element to change as the pixel rows are being scanned, leading to visual artifacts. This is easily seen when an iPhone takes pictures of an aircraft propellor. I think the same thing is happening to the webcam – the LED light is strobing as the image sensor is scanning rows of pixels. This is seen as visual stripes in the webcam output :-/

How is this solved? One way is to change the PWM implementation. The LED must remain lit short enough to strobe once every pixel row scan OR the LED can remain lit long enough that the entire image is scanned in one go. This latter solution works for still images – I’m not sure how it would hold up in video. Finally, the LED’s current could be controlled directly. This is the ideal solution that will allow the LED to remain constantly lit while being able to alter its brightness.

Telecine_Output

 

Projection hole

I drilled a hole through the back of the plate I made earlier to allow the film to be viewed. Due to space constraints, the backlight is mounted in the front of the projector where the lens was originally and the image is projected in reverse.

Telecine_8mm_Film_Rear

 

Lens

The lens is now mounted to the rear of the projector. At this stage, the mounting is temporary – as you can probably tell by the zipties. Instead of enlarging the image, the lens now serves as a macro lens providing approximately 1:1 magnification. I’m actually using the original lens for this demo, but I also purchased a new zoom lens from eBay.

Putting it all together

Telecine_BacklightTo the left is the current state of the backlight. There are four wires soldered to it – common, red, green, and blue. At full brightness with the resistors I had in my shop, the backlight casts a purple light; this was supposed to be remedied by the Arduino. Indeed, the Arduino is able to control the backlight color – but with visual artifacts, a new solution is needed.

 

Telecine_Webcam_Projection_CloseOn the right, you can see the lens barrel (far right silver object), the webcam board in the center with the blue power LED, and the projected image itself on the sensor in the center. Remember, this is the bare webcam without any lens at all! It’s all held in temporary place by a “third hand” soldering tool so it’s not in the best alignment.

 

Below is a wide view of the setup, with the white arrow pointing to the projected image. Here you can clearly see the zipties holding the projector lens in place. Additionally, note that the backlight now casts a warm white light – this is from the adjustment provided by the Aduino.

Telecine_Webcam_Projection

Finally, here’s a video of it in action.

 

How to Vinyl Dye Your Parcel Shelf

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I picked up a (formerly) black parcel shelf complete with premium rear speakers for my e30 at the junkyard. Here’s how I renewed this parcel shelf with some vinyl dye and sweat.

First, meet my parcel shelf, complete with plenty of dog(?) hair.

Original Parcel Shelf

Next, you need to prep it for dye. This involves removing all the accessories, like the speakers, third brake light, vents, and seat belt trim. If your’s has a hair problem like mine, a lint roller will do wonders to clean it up. Remember – the key to a good final product is in the preparation!

Prepped Parcel Shelf

All prepped!

 

DuplicolorNow, get yourself a couple cans of vinyl dye. I used Duplicolor as seen here. One can will probably get the job done, but pick up two to be safe. Spray many light, consistent coats in many directions to get full coverage. Vinyl dye is more forgiving than spray paint, but if you go heavy in one place – well, you’ll need to go heavy everywhere for it to look right! You will be fine just spraying dye on the parcel shelf, but for carpet or other “deep” fabric, the dye will need to be brushed into the fabric for full coverage. Once you get one good coat, let it dry for 15-30 minutes, then hit it again. I went with at least three coats to achieve my final finish. Again, vinyl dye is forgiving – it doesn’t really run and just gets absorbed into the material, but heavy applications will make cloth materials feel stiff.

 

Here’s my first coat

First Coat

 

And eventually you’ll end up here, the bottom result. The top was dyed by my friend and requires more coverage. On the plus side, it’s been exposed to constant sun for over a year and has not faded!

Final Product

LED Tag Lights

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One of the tag lights was out on my e30 making for a good mod opportunity. I figured LED lighting would help update the look of car, so I ordered these guys from Amazon.

E30 Rear at Dusk

E30 rear at dusk with LED tag lights

They look good to me! I know the camera doesn’t do the best job, but just compare the license plate white to the yellow light given off by the incandescent lights in the background!

New LEDs!

New LED lights on the left, comparison of the original halogen light vs an LED light right

Installation is a snap too. Just find your tag lights, remove the screws (hopefully they’re not as rusty as mine!), pop the light out, replace the old halogen lights with the LED replacements, and reinstall. Be sure to test the LEDs prior to reinstallation – direction matters. Also be sure to orient the LED facing down.

Install Process

 

Here’s a quick comparison of new vs old:

Old halogen light (left) vs new LED light (right)

Old halogen light (left) vs new LED light (right)

Note: The LED rotated in its socket as I installed it for this shot. The new LEDs are actually much brighter (as seen in the opening shot).

6 Tips for Great Kodachrome Scans with Nikon Scan

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I’m still learning, but slowly perfecting Kodachrome scans. My preferred software package for working with Kodachrome is the good ‘ol Nikon Scan. If you are running Windows 7 x64, don’t fret, I have a solution for you here.

Okinawa 1952

Okinawa 1952

1. Use the Kodachrome profile in Nikon ScanKodachrome Profile

Nikon has already done the hard work for you and profiled Kodachrome which has a unique color signature. Use this to your advantage and select the “Kodachrome” profile in Nikon Scan to see nicely color corrected scans!

Kodachrome Profile vs Standard

Kodachrome Profile (left) vs uncorrected Epson V330 scan (right)

2. Use the “Fine” Digital ICE setting

Kodachrome is exceptionally challenging film to scan and only the Nikon Super Coolscan 9000 ED is capable of perfect dust & scratch removal. The Coolscan V & Super Coolscan 5000 have a special Kodachrome version of Digital ICE that does a pretty good job of removing dust and scratches without futzing up the detail. Use it! For more damaged slides, change to the default “Positive” profile and select “Normal” Digital ICE. This will lose detail, but also better correct your scans. I find “Normal” Digital ICE correction to be too light handed to be useful in the Kodachrome profile. While using the “positive” profile, your Kodachrome slides will exhibit a dreadful color cast. You can get close to correcting this by enabling “Digital ROC” at level 5 and dialing in -48 red, -44 green, and +4 blue in the Color Balance section.

ICE Comparison

“Positive” with “Normal” ICE (top), “Kodachrome” with “Fine” ICE (middle), “Kodachrome” without ICE (bottom)

3. Scan with the emulsion (dull) side facing down

For the best quality scans, scan with the emulsion side of your slides facing down, towards the sensor. You can tell which side is the emulsion side by looking for the dull side of the film – the other side will be glossy.

4. Clean your slides prior to scanning

Digital ICE is not a golden parachute. Your scans will look better with less correction, so clean them (or at least dust them) prior to scanning. Your scanner will thank you too!

 5. Use the Analog Gain settings to your advantageAnalog Gain

Some slides may be appear to be overexposed or underexposed so badly that they are not salvageable. Fear not! Analog gain changes the backlight intensity / scan speed allowing new life to be breathed into these slides. It works like exposure on a camera – add gain for underexposed, dark slides and subtract gain for overexposed, overly bright slides. You will be surprised what can be recovered! For more advanced users, tune analog gain to be as positive as possible without blowing the highlights to reduce the noise in your scans.

Gain Comparison

+.71 analog gain (left), no gain adjustment (right)

 6. Scan and save using the highest quality available.

Scan using the highest bit-depth available, 14-bit for the Coolscan V and 16-bit for the LS-5000, and save the output as a TIFF. At 4000 DPI, this will create 100+ megabyte files. This allows edits to made using the highest quality source and will render a better final output. Once you are done any edits, the original TIFFs can be deleted – or better, archived for future use.

Nikon Coolscan V and Kodachrome

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In conjunction with the telecine project (updates soon!), I purchased a Nikon Coolscan V, also known as the Nikon LS-50, to scan in my Grandfather’s 35mm Kodachrome slides from the early 1950s. The Coolscan V is appealing for its 4000 dpi optical resolution and a fourth version Digital ICE automatic dust removal. However, Digital ICE does not work with all films.

Kodachrome slide from 1952

Kodachrome slide from 1952 with Digital ICE

ASF’s, now Kodak’s, Digital ICE performs automatic dust and scratch removal – the ICE being short for “Image Correction and Enhancement.” It works by scanning a fourth, infrared, color layer in addition to the conventional red, green, and blue layers that is used to create a dust mask which is later subtracted from the scan. The infrared light is expected to pass through the film emulsion but not through dust. So why doesn’t it work with all films? It turns out that black and white film uses silver nitrate for the emulsion layer, and silver nitrate also blocks infrared light, rendering Digital ICE useless. So now you’re probably asking, “So what does all this have to do with Kodachrome? It’s color!”

Kodachrome is not a normal color film and shares more in common with black and white film than color negatives or the typical color reversal (positive) film. This is easily illustrated by looking at a Kodachrome emulsion which has a 3D appearance – these are the color layers in the film, and each color layer is very similar to traditional black and white film. In fact, Kodachrome starts out as black and white only to slowly become color during its long and convoluted development process. These days Kodachrome can no longer be developed as color film because the chemicals necessary for development are long out of production. Owing to its similarity to black and white film, old, undeveloped Kodachrome can still be developed in black and white!

So how does the Coolscan V’s implementation of Digital ICE work with Kodachrome? The answer is “it sort of does.” The Coolscan V does a good job with removing dust and an alright job removing defects from a slide. That’s where the good ends – Digital ICE detects strong contrast areas as defects and tries to remove them, leading to blurry images with noticeable defects at 100% crop. Where real defects, like scratches, exist, a mark is often left on the image although it is significantly less noticeable than an uncorrected scan. Furthermore, I have noticed instances where defects are seemingly introduced to the scan.

100% crop with Digital ICE

100% crop with Digital ICE

Pay particular attention to the orange handle and the sailors’ faces. ICE detects these fine details as defects and completely mangles the image. I think the Coolscan V still manages to extract more detail with ICE enabled than my Epson V330 flatbed does without ICE.

100% crop without Digital ICE

100% crop without Digital ICE

Digital ICE reduces images sharpness when fully enabled, even when used properly with color negatives. This side effect is worsened with Kodachrome – even at web sizes, the loss of sharpness is clearly apparent.

With and without ICE

ICE (Fine) on the left, without ICE on the right. Scanned using the “Positive” setting, not Kodachrome.

Even with the Coolscan V’s more advanced fourth version of Digital ICE, it is clear that Kodachrome does not play well. Home users will likely be happy with the results, but a professional will not. There is exactly one scanner on the market that can properly remove dust and scratches from Kodachrome, and that is the Nikon Super Coolscan 9000. I will continue to leave Digital ICE enabled since the corrected, dust free slides look much better than sharp and dusty slides to my eyes.