How to bring 4x5 and 6x17 slides on to 6x4,5 film

[Pere Casals]

If you are projecting them anyway, why not just scan them into image files and project them from a computer with an LCD projector?

Let me point what happens then:

1) Image ressolution , a Provia/Velvia 4x5 has an IQ equivalent of 200 MegaPix, a video projector may trow some 2. You loss 99% of the IQ

2) Colors, the infame sRGB triangle monitors and TVs have are not a great thing, Velvia colors would make a hard man cry (in AC/DC wording). This will be better when standard "Rec. 2020" in use, but for now...

3) Static contrast, in a common TV this has a (crappy) 1:100, Velvia DMax 4 (Minus DMin) is some 1:3000, 30 times better. Projected both decrease... true, but an equivalent performance ratio may be there.

Note all of them (manufacturers) talk about "Dynamic Contrast" being 1:10000000000000, in fact it could be infinite, with a perfect black if scene regulation completely shutdown rear TV lamps. Static contrast talks about contrast displayed in a single frame, and this is the significative thing.

[Pere Casals]

mount the slides in opaque masks that completely cover the glass plate of the projector. The big problem with those is that they spray
stray light all over the room.

Thinking about it, you are right the masks are important, also perhaps, to cancel stray light, a cloth cone can be placed from slide to the overhead mirror.

Getting enough light through a view camera is really going to be a challenge. A condenser head from an enlarger is a starting point, but projection images are subject to the inverse square law, and the viewing space will never be as dark as a darkroom.

Rick "sorta liking the overhead projector idea" Denney

I use a Cambo 8x10 as a projector to project 8x10 BW slides from an contact interpositive, as condenser type illumination source I used the illuminator (with its Fresnel) from a broken overhead projector, also I tried with a MF projector (with no slide) throwing light to the slide (in place of the GG), so plain solution. The lens, a Sironar N 300...

Now I want to use a powerful (colder) LED source to reach some 3000cd/m2...

How can I describe the result ??? Lets say than one can cry of emotion !!!!!

I feel this like photo-graphy, "photo and graphy", capturing photons and throwing photons with little in the middle. Purity...

Difficult to explain how much detail and dynamic range and static contrast appears on the wall by throwing there a 8x10, one has to see it, and then one may cry...

I bought expired 4x5 and 5x7 Velvia and Ektachrome to go forward.

How many times do we look at a sunset and we figure that we can capture a composition but little of that magic ?

Projecting a 4x5 Velvia/Provia (or BW !!!) is projecting that magic !!!!


Note that one may take advantage of Velvia DMax 3.8D, now I'm testing to shot high contrast scenes being shadows way underexposed, and then throwing a lot of light throught the slide, I'll try to adjust process for optimal projection peformance. BW film usually reach DMax 3, Silvermax can go closer to Velvia, in terms of DMax, but it's 135 only, also charming.

[Drew Wiley]

Depends on your expectation of quality. A lot of this is easy in theory but a real chore to get right. Finding a suitable duplication film like Astia that is not out
of date is the first problem. Then you need to precisely color balance the light box or duplication camera itself, get the original film nice n'flat, and hardest of all,
control the excess contrast of the original. Flashing is the traditional method to do this, but inherently degrades the quality of the lower values in the image. I prefer masking; but this is way too much effort for casual usage. Digital projections are like eating half-melted imitation ice milk instead of real ice cream. Velvia
is a horrible choice for duplication work. If you can't find any frozen Astia, try for E100G.

[tgtaylor]

There was a 4x5 Noblex projector that sold for ~$3,000 in the late '90,s/early 2000's. I saved for one but when I finally had the money together, it was discontinued. I looked for a used one for some time before giving-up. Only one turned up on ebay for $2000 but it was from an east European seller with a 0 rating - not enough at the time to qualify for the ebay buyers insurance. I sure that if you looked long enough, one will turn-up. If that happens, I have a few hundred 4x5 cardboard Blaire mounts you can buy.

http://www.cameras-scanners-flaar.or..._projector.htm

Thomas

[Tin Can]

Thinking about it, you are right the masks are important, also perhaps, to cancel stray light, a cloth cone can be placed from slide to the overhead mirror.





I use a Cambo 8x10 as a projector to project 8x10 BW slides from an contact interpositive, as condenser type illumination source I used the illuminator (with its Fresnel) from a broken overhead projector, also I tried with a MF projector (with no slide) throwing light to the slide (in place of the GG), so plain solution. The lens, a Sironar N 300...

Now I want to use a powerful (colder) LED source to reach some 3000cd/m2...

How can I describe the result ??? Lets say than one can cry of emotion !!!!!

I feel this like photo-graphy, "photo and graphy", capturing photons and throwing photons with little in the middle. Purity...

Difficult to explain how much detail and dynamic range and static contrast appears on the wall by throwing there a 8x10, one has to see it, and then one may cry...

I bought expired 4x5 and 5x7 Velvia and Ektachrome to go forward.

How many times do we look at a sunset and we figure that we can capture a composition but little of that magic ?

Projecting a 4x5 Velvia/Provia (or BW !!!) is projecting that magic !!!!


Note that one may take advantage of Velvia DMax 3.8D, now I'm testing to shot high contrast scenes being shadows way underexposed, and then throwing a lot of light throught the slide, I'll try to adjust process for optimal projection peformance. BW film usually reach DMax 3, Silvermax can go closer to Velvia, in terms of DMax, but it's 135 only, also charming.

I also tried OHP with large slides. No Good. Now I think a horizontaL enlarger is way better. I can now throw 5x7 slides very well with my DIY LED Head, which is not the one I was using last year with Makrolon Diffusion.

Since I get too much negativity here from 'experts' I seldom share my success.

Next 8X10 projection. When I can afford it. Battling City Hall and Taxes today.

[Pere Casals]

Finding a suitable duplication film

yes... preflash is the classic recipe, but the result it's not the same. As Astia/Sensia is not there then too much preflash would be required.

Clearly contrast control is a main concern... An option may be a pull. Provia 100 shot at ISO 12 and then developing N-3, this is with Tetenal Colortec E-6 kit, mantaining First Developer time but decreasing Temperature from 39ºC to 28.6ºC, the rest of the process as always.

http://www.freestylephoto.biz/pdf/pr...structions.pdf

I've not tested it, but as I'm starting with Velvia sheets, I've planed to make some tests by acting on First development... the 2nd developer is way more intouchable I think, withoug going to lomography results : )

Perhaps another option would be using seasoned first developer with reduced or no agitation, instead rotary. Same tricks than with BW film may work with first developer, but a lot of test have to be done, I think...

Velvia is a horrible choice for duplication work.

Way sure !!! But with Provia perhaps it may be a question of contrast control and perhaps some slight preflash to control oversaturation, again a lot of tests...

Digital projections are like eating half-melted imitation ice milk instead of real ice cream.

Drew, please call the things by its proper name : ) , it is not possible to define digital projections without including the "bull" word, : ) (just joking a lot !!!!)

[Pere Casals]

I also tried OHP with large slides. No Good. Now I think a horizontaL enlarger is way better. I can now throw 5x7 slides very well with my DIY LED Head, which is not the one I was using last year with Makrolon Diffusion.

Since I get too much negativity here from 'experts' I seldom share my success.

Next 8X10 projection. When I can afford it. Battling City Hall and Taxes today.

A challenge for 8x10 projection is the lens, it has to be fast and afordable, I was thinking about something like this:

http://www.ebay.es/itm/Leitz-Leica-L...YAAOSwfZ1WbA0Y

f4, this saves half of heating in the slide, to obtain a bright image. A lot of MF projectors are f/2.8, so having f/4 for 8x10 is great preformance.


About OHP, projectors that has light source at the top are for document and won't work, but the ones that have the light source (with a fresnel) under the slide can work pretty well, just a mask for the slide is necessary, and a pyramidal cloth cone from mirror to slide to cancel stray light.

[Tin Can]

A challenge for 8x10 projection is the lens, it has to be fast and afordable, I was thinking about something like this:

http://www.ebay.es/itm/Leitz-Leica-L...YAAOSwfZ1WbA0Y

f4, this saves half of heating in the slide, to obtain a bright image. A lot of MF projectors are f/2.8, so having f/4 for 8x10 is great preformance.


About OHP, projectors that has light source at the top are for document and won't work, but the ones that have the light source (with a fresnel) under the slide can work pretty well, just a mask for the slide is necessary, and a pyramidal cloth cone from mirror to slide to cancel stray light.

That's a nice lens and i would buy it, but not this month. I have a fast lens from my OHP.

I did try an OHP under table light with fresnel, not good enough. I now have a powerful LED source for 5x7. Not too hot and horizontal projection is more easily cooled. Heat rises, they tell me. Color temp is not ideal. Yet. But LED are improving constantly while prices drop.

I'm using old enlargers with Rodagon lenses. Been planning this for 5 years. A 5X7 Elwood tips horizontal in little space. Throw the light on a good screen. Of course the old screens, which we all have, induce a 'coarseness/grain effect. Still playing.

I also have a good stash of old stock LF Chrome film. 4x5 in the 5x7 rig for now.

[Pere Casals]

Color temp is not ideal.

Color temp can be adjusted with gels, but problem is other, I think: that SPD that LEDs have !!

I'm a bit focussed to BW slides, until now in smaller formats to learn https://www.flickr.com/photos/125592...posted-public/

I found that light source for BW projection is less critical, but to show velvia colors like they are... there is a need (I guess) of an illumination that has an spectral power distribution SPD close to Hallogen.

It would be necessary to see in LED datasheed shows how it spreads power over visible range. Perhaps by combining more than one LED source the Hallogen SPD can be matched aproximately.

Problem is that some LEDs have some narrow band R,G,B channels, and deep reds, for example are not seen as it should.

A bit it's like viewing a cloth fabric inside a shop or at daylight.

A good option is a xenon arc lamp, if you look at its SPD here https://en.wikipedia.org/wiki/Xenon_arc_lamp

it makes clear why it was used in movie theaters. Just need a hot mirror to reflect out the infrarred peaks.

Anyway slides are transparent to infrarred and retain an small amount of IR energy, you can see it with a Sony "night shot" video camera: in "night shot" mode it retires the IR blocking filter, and black velvia slide will appear transparent when illuminated with a tugnsten light (90% is IR). But this only happens with color slides, as they have organic pigments. BW slides (silver) is not transparent to IR, and gets more heat.

[Tin Can]

Perhaps you missed a recent experiment. X-Ray enlarged Positive from 6X17.

Not great, but a test. See this link.

http://www.largeformatphotography.in...=1#post1338876