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As I have stated before I have found the best method to be a Integrating sphere. That makes it much easier to have many different lightsources for testing and also makes it possible to mix them for...

There is also stuff like this http://www.lightillusion.com/matchlight_ims.html but as with most special stuff in the film industry its quite expensive. I use some other software for calibrating...

You can use Davinci on photos but its a bit cumbersome. Resolution is dependant on graphics memory and there is a ceiling around 5-6k on the more extreme hardware. My dayjob is in postproduction of...

Hi There!

I always had the best result from building a integrating sphere with leds as lightsource. What you need is a sphere with a diffuse interior. The hole should only be 5-10% of the surface...

Looking good!
I am eager to see a video, pretty please with sugar on top?

Ludvig

Very interesting.
Thanks for posting this, it is very encouraging to see you getting so good results.

Keep up the good work

Ludvig

This looks very good!
I have some questions for you if thats alright?

How long time do you estimate a scan takes? With mounting, taking the pictures and postprocessing(stitching)?

Do you...

Rudi, thanks so much for helping us out on this! I am a complete amateur and I dont understand the scientific words you mention but I understand "7 led". At least i think so. Could you descibe a bit...

This response curve is for ektar. Not exactly a good "cri" or blackbody response. In my experiments I have chosen leds with a similar wavelength to the peaks in colornegatives and my sensor.
97379...

In my tests with negative color film I have had much better results with rgb led then with sunlight. I think that when you stimulate the r g and b photosites without any splill between them you get a...

But how important is CRI? I know that drumscanners use Tungsten but the Nikon Coolscan series wich is more or less the goldstandard for 35 an mediumformat scanning ises rgb led.

I dont know how that three knob controller works but I guess that its PWM and has some transistors inside. If you wanted to you could easily drive the arduino with those pots and have arduino pulse...

Well if you want to control red green and blue with PWM from an arduino and control the light levels on r, g and b with digital control from 0-255 you could do it with three power transistors and one...

Yes I have the same it is crazy bright! Here is the sketch I made to maximize leds per square mm. I am looking forward to seeing this in action.
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Interesting!
I was also thinking of using rgb ribbons in a woven grid with diffusion. Also looked into using an acrylic with etched backface and filters like on a led tv, just replacing the...

Any news here? I am probably going back into this project again later this year. My wife just got bit by the largeformat bug. I have some new ideas too...

Ludvig

Sweet rig!
Is it Misumi or similar or did you machine the parts yourself? Can you give me a ballpark figure on the mechanics?

Looking forward too seeing more, keep up the good work!

cool! Nice to see some code Peter!

I think its best to just jump in like you do and try stuff out. Probably you will find more stuff out when you have the motors driving your rig. A couple of...

CRI not important? Finding and matching sensors sensitivity to r, g and b respectively better?

I have done a lot of test on negative color film and my best results so far comes from RGB LED. I can...

To David:

I have built a setup to make digital "contact sheets" of all my archive of negatives. These are mostly 120 film in A4 plastic sheets. I used a 24inch screen for this with a diffusion...

I only machined the parts touching each other and I have not machined the surfaces of the slides themselves. There i a weakness to my design though that could be easily fixed by mounting the slides...

I did some tests by just laying a piece of glass on top of the stage and running a program with a dial indicator measuring of the glass. Over the distance needed for acquiring a 6x7 neg I only had a...

Yes the IR is for dust and stuff. I will use photoshop to do the removal though, the new algorithms from cs5 and up(like content aware fill) are fantastic. I tested it with a raw scan with a IR extra...

I havent finished the negative carrier and the whole top frame needs to be trammed or aligned. But when its perfectly aligned it will hopefully not be more then 0.05 mm.

The math tells me I need...

yes most stuff came from a "home depot" type store. Standard metric square aluminum tubing, cabinet drawer sliders etc. All mechanical stuff like belts, pulleys and bearings come from old broken junk...

Here is the code running in this demo.


#include <AccelStepper.h>
#include <Encoder.h>


// Define a stepper and the pins it will use
AccelStepper stepper1(1, 6, 7);
AccelStepper...

more pics
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https://vimeo.com/46986255

Finally got some time to finish the machining on the second axis on the stage and got all the parts for building the electronics. Here are some pictures of my first run. The two rotary encoders are...

I have done quite a lot of testing on color neg lately. I have tested different LEDs, flash, sunlight, tungsten in my dslr scanner up against a hand tuned scan in Nikon coolscan 8000ed. With...

The uneveness is not a big issue at least not for me. I have done some testing where I take a picture of the lightsource and use to divide the uneveness from the lightsource. This also takes out any...

I googled quite a bit and could not find a good description on how a de vere box is constructed. It seems to involve two lightsources and a mirror plus some diffusor? Do you have a picture I could...

I have built a lightbox for flash. It works ok and is almost even but I am having trouble getting anything larger than 40x40mm even with my design. Ideally I would want something bigger so I can use...

Also the older digital backs arent that much larger, a h20 is 36.9 x 36.9mm and a 5d is 36 × 24 mm the 25s are a bit larger at 48.9 x 36.7 but still I think it is not worth it.

I was in a large hardwarestore today picking up some supplies for my house and I had a look at the drawer slides they had just for fun. I bought a small ball bearing sliding unit 310mm long. It was...

Like I said before I intend to project a laser pattern on the film and run one full cycle like that first when I start each batch, I will the stitch first using the laser pattern to make a perfect...

I looked around on some american vendors and updated the BOM with american prices. Its around $250. Here in norway it costs me around 320 but I already have most of the stuff anyway. I look forward...

I made a sketch based on aluminum profiles and drylin N 27mm sliders. Its quite cheap maybe around 200 bucks. Here is a small animation and a picture of drylin sliders

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If you want to...

I have worked out my plans for most of the aspects of this but one part is very unresolved in my mind. The issue of mounting the film. Since I am only interested in 120 film I have looked at some...

Yes these are quite good, I have a similar solution on my manual milling machine. But they have their readouts on the slider.
http://www.arceurotrade.co.uk/Catalogue/Measurement/Digital-Readouts...

I think they look good all of them, they all clearly resolve the grain in the film. Its hard to judge color spectrum differences on the different lighsources on black and white though. What would be...