Print quality after dslr scan

Gorbas: If I may, have you pursued this approach with LF 4X5 at all? I'm using Negative Solutions holders for smaller formats, and have thought of the PB-5, but never thought of how to attach an enlarger lens. Will enlarger lenses work with a PB-5? And then I assume a Nikon D750 works with the PB-5 as well? Sorry to both you, just always doing what I can to push the envelope and 1) get high quality and 2) do this thing at speed as well. Thanks!

runswithsizzers said:

I know from personal experience that a 100mm enlarger lens mounted on a Pentax Bellows Unit II works for both 135 and 120 formats when copying with an APS-C sensor camera. I'm guessing an 80mm lens would also work, but have not tried it.

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I'm hoping that a 105mm enlarging lens will be sufficiently long for 6x7 with a micro 4/3 sensor, but I've yet to receive all my necessary step-up and reversing rings to be able to say for sure.

Sorry, using it only with 35mm and 6x6. I had trouble attaching old (the first model of Nikon F bellows) to modern digital nikons body. Designs of the prism and cameras changed over the the last 50-60 years. I did not have any issues with attaching PB-5 with D7000, D600 and D810. Yes, you can attach enlarger lens to Nikon bellows. Look for M39 to Nikon F adapter or combination of M39 to M42 and M42 to nikon. Don't forget to plug inside chanel for f stop illumination, if you enlarging lens has it!!!
Speed is the main thing for me. Uncut 36ex negative roll I can scan between 8 to 10min. With cut negatives I need around 12 min for 36ex. It will take me better part of the day to do it with Nikon Scan film scanner. I still scan my most important negatives.

MattKing said:

I'm hoping that a 105mm enlarging lens will be sufficiently long for 6x7 with a micro 4/3 sensor, but I've yet to receive all my necessary step-up and reversing rings to be able to say for sure.

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I tried a 105mm bellows Pentax on the Durst slide copier yesterday. I still get too much magnification. The Durst has a limitation of distance, so a different set-up may be needed.

based upon this conversation, and the tortured processes it describes, it's clear that when god invented analog then digital photography she never meant them to cross-pollinate, hybridize or be used together - it's just unnatural!!!!

JVO whatever floats your boat! I have fun doing both I just made myself one promise. I will never coat my own photo sensitive material.

gorbas said:

JVO whatever floats your boat! I have fun doing both I just made myself one promise. I will never coat my own photo sensitive material.

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isn't it interesting how one persons grey cells handle one type of complication while another persons are at the other end of the spectrum - vive la diffe'rence!

p.s. give me some credit, i did just buy my first digital camera a couple of weeks back... i have every intention of taking my first picture with it before the end of the summer!

Try it sooner, please! Its fun!

I have been experimenting with a 4x plan-achro microscope objective plus stitching using a crop sensor camera to acquire the images. I have a way to go before I know how good this approach can be. I am already seeing one issue, namely that stitching using photoshop does not always work very well. Sometimes there are significant errors in the stitched photos. Hugin might be a better way to stitch, but for Hugin I am finding a fairly steep learning curve.

Also, it requires a relatively huge number of photos to be taken of a single negative, which is time consuming in addition to the issue of having a good stitching solution.

It remains to be seen how well the color fidelity issue will pan out.

In principle, with this approach it should be possible to equal or exceed the quality of a drum scan.

On my rig I did rephotographing of 56mm long panoramic negative taken with 35mm film in 2 shots, left and right and it worked quite well. I don't think I have patience or desire to do anything more elaborate

alanrockwood said:

In principle, with this approach it should be possible to equal or exceed the quality of a drum scan.

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Yes, it is possible to beat a top drum scanner by stitching a 3x3 dslr mosaic of a 35mm shot. To beat the scanner with MF or LF film you need many crops stitched. Still this requires a substantial effort and good skills

As always it's not much benefical to go beyond a certain point as many times there are other limiting factors, many shots won't see a benefit beyond 3000dpi effective resolving power, many times beyond that we only may obtain a more defined grain depiction that may be seen well beyond x10 enlargements.

alanrockwood said:

I have been experimenting with a 4x plan-achro microscope objective plus stitching using a crop sensor camera to acquire the images.

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The 4x Plan may require a relay lens, is it infinite focus corrected type?

For top resolving power you may try a reversed enlarger lens, adjust magnification to make the projection on the sensor be around 4 times larger than the original, in thise conditions a Nikon EL 50 f/2.8 stopped at f/5.6 or f/8 will deliver around 10.000 dpi effective witch beats any drum in effective dpi terms, this is very cheap and probably and probably the easy way. Still there are other factors like dynamic range and color accuracy...

You also may add a window in the rear to frame a crop matching the sensor size, if not excessive illumination circle of the optics may generate flare, or you may mask on film to frame only the region the sensor sees.

alanrockwood said:

It remains to be seen how well the color fidelity issue will pan out.

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The DSLR scans won't deliver "good" colors straight from the acquisition, for sure you may obtain the same colors than with any other systems but there is a substantial effort in that. You may simple shot a color checker and make a calibration, but this is not the end of the history...

Color film has evolved over a century by delivering sound color interpretations o different subjects that are beyond color accuracy or neutrality.

Let me say an analogy. Electric guitars and valve amplifiers have evolved over decades together, with the armonic distortion provided by the valves being incorporated in the aesthetics, today a solid state amplifier may have to add something to the technically perfect linear amplification if wanting a cool sound from guitars.


In the same way a perfect color calibration of the dslr scanning won't deliver those colors that make a hard man cry, you need something more to exploit the film spectral interpretation, this is specially well seen in portraiture: nailing those tonal nuances that Portra/Fuji 160 can deliver is not that easy.

Silverfast has "Negafix", this delivers an specific color mapping for each kind of film. That mapping is not an easy color balance you may emulate with a few mouse clicks... I guess that mapping is inspired in the RA-4 interpretation of the inverted colors in the negative.

So a way to calibrate the DSLR colors would be making a calibration that maps the DSLR result with the Negafix results for each film type. Perhaps an easy way may be the Color Matching feature of 3D LUT Creator tool, to get a 3D LUT that can be used in Photoshop.

With slides color is easier, the slide itself is the reference, with Color Negative film there is no absolute reference, and color interpretion has to be sound for a refined result.

I haven’t combed through this thread, so excuse me if this is redundant:

LED lighting is mostly a bad idea for colour film scanning.
Look at your light source in the reflection of a CD, or better yet a real diffraction grating.

If you see many coloured iterations of the light source then you have a problem (which most certainly will be the case).

Most LED light sources have big peaks and valleys in their spectrum. These are mostly impossible to correct in post.

That of course includes all LCD screens (not sure about OLED (but pretty sure it isn’t even)), all light pads and panels.

I’m told there is a few LED RGB lights sources that are better, but mostly LED is only good for focusing on the film.

For the best result use a powerful Flash.
Flash has a spectral signature very near noon daylight.

Flash has the advantage of being so strong that you will be able to stop as much down as you need, and of course use the lowest ISO setting.

Also, it will allow you to piss away a lot of the light in dispersion and getting an incredibly even field of light.

Helge said:

Most LED light sources have big peaks and valleys in their spectrum. These are mostly impossible to correct in post.

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A good LED illumination is perfect for scanning if it is of high enough CRI (96 rate is excellent), anyway if you see the SPD graphs of good CRI LEDs... they are way better than those fluerescent lamps in high end flatbeds, like the Sylvania F15T8 used in the highly expensive Creo machines.

In particular the newer LED illumination in the EPSON V850 has absolutely no drawback compared to the non LED previous V750 model, being the V850 color rendition absolutely top notch.

138S said:

A good LED illumination is perfect for scanning if it is of high enough CRI (96 rate is excellent), anyway if you see the SPD graphs of good CRI LEDs... they are way better than those fluerescent lamps in high end flatbeds, like the Sylvania F15T8 used in the highly expensive Creo machines.

In particular the newer LED illumination in the EPSON V850 has absolutely no drawback compared to the non LED previous V750 model, being the V850 color rendition absolutely top notch.

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CRI is a very flawed standard.
It’s quite easy for a manufacturer such as Epson, who does the whole hog, to correct for deficiencies in the light with software and filtering.
Not so for the DIYer who is piecing the whole thing together from disparate parts.

Helge said:

CRI is a very flawed standard.

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This depends on if you use the Ra standard proposed in 1960s or the R96a standard made in 1990s.

The R96a method ads six colors (four are quite saturated), the last six in this table, and it's a quite reliable method in any situation:



To a LED obtain a CRI 96 or 98 the spectrum has to be really, really good, you will need very specialized Lab equipment to notice a difference, and it's quite difficult you notice a flaw.

Good LEDs (violet LED source) even surpase Ceramic Discharge Metal-Halide lamps in light quality. Today we can obtain very high quality LEDs at bargain price, in the past this was not like that.

Or on any doubt you may use the TLCI index... but for high CRI light sources spectrum has to be really good anyway. With a source of CRI R96a 96+ rating you won't have problems. Any flaw in the CRI method is not an issue for the high CRI R96a ratings, because to get a high rating you need a really good spectrum.

i can't tell you if something like this will work but years ago Polarood made a slide copier. It was a rather simple device. For those who are handy you might be able to rig something like that to use as a scanner with the DSLR taking the place of the film. Perhaps not needing a lens on the camera and a fixed distance from film to the sensor.

http://www.jeffreyglasser.com/

http://www.sculptureandphotography.com/

They also made a slide printer which is what i was thinking about in the post.

jeffreyg said:

Polaroid made a slide copier

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Are you thinking about this? If it's not right thing, can you please post a picture of it?

Enlarging lenses perform poorly at 1:1 compared to true macro lenses. As well, true macro lenses resolve well at (for example) f/4... enlarging lenses are considerably less sharp at full aperture. .

Reversing is intended to allow focus to shape better around small 3-d subjects, such as bugs. It doesn't help with relatively flat subjects.

Inkjet printing deliver far more if one is willing to learn how to print, than if one expects the printer itself to do all the work...and that's not even considering the contributions of fundamental software such as Photoshop and NIK....which doesn't necessarily involve sharpening.

It takes a little time to acquire basic digital printing skills....with those minimal skills one will demand more from their inkjet prints than they ever demanded from enlarger...and inkjet printers allow papers far more subtle, with far more options, than available with darkroom papers.

Another thing...using a DSLR (old fashioned digital camera) with continuous light (e.g. light box) you will almost certainly need to lock up the mirror. Big win for mirrorless over DSLR.

Flapping mirrors were acceptable for routine photography except with very long lenses... definitely a handicap for slide copying etc. Easy to see..not subtle. Macro work makes short exposures crucial. 100th is a LOOONG exposure for macro...seriously impacts sharpness.

MattKing said:

You may find it challenging to get the entire 35mm negative into a crop sensor (D3200/3300) frame if you are using a bellows and an 80mm lens. Even a 50mm lens may be too long.
The thickness of the bellows leads to higher magnification than you will want, unless you use a lens that matches better with the size of the sensor.
A 50mm enlarging lens may very well work with the bellows, a crop sensor camera and 6x7 originals.

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I use a 70mm macro lens on a 32MP crop sensor and have no issues fitting a 24x36mm frame onto the sensor. Heck, I regularly scan 35mm half frames with no issues.

Adrian Bacon said:

I use a 70mm macro lens on a 32MP crop sensor and have no issues fitting a 24x36mm frame onto the sensor. Heck, I regularly scan 35mm half frames with no issues.

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I use 50mm Pentax SMC-A Macro with 30mp APS-C camera. Use of any lens with bellows might introduce alignment issues because bellows front/rear standards aren't as perfect as is mount alignment with film plane.

Adrian Bacon said:

I use a 70mm macro lens on a 32MP crop sensor and have no issues fitting a 24x36mm frame onto the sensor. Heck, I regularly scan 35mm half frames with no issues.

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It has become clear to me that the problems I and others have encountered are due to the configuration of bellows and slide copying units. The problem that I (and others) run into is that the minimum camera to lens distances and maximum lens to subject distances imposed by the bellows and slide/negative copying equipment designed for film duping often result in too much magnification when crop sensors are employed.

138S said:

...The 4x Plan may require a relay lens, is it infinite focus corrected type?

For top resolving power you may try a reversed enlarger lens, adjust magnification to make the projection on the sensor be around 4 times larger than the original, in thise conditions a Nikon EL 50 f/2.8 stopped at f/5.6 or f/8 will deliver around 10.000 dpi effective witch beats any drum in effective dpi terms, this is very cheap and probably and probably the easy way. Still there are other factors like dynamic range and color accuracy...

You also may add a window in the rear to frame a crop matching the sensor size, if not excessive illumination circle of the optics may generate flare, or you may mask on film to frame only the region the sensor sees.

Click to expand...

The 4x plan achro lens I obtained is not corrected for inifinite image distance, so it doesn't need a relay lens. Mine is corrected for 160 tube length.

It is unlikely that an enlarger lens (reversed or not) will beat a 4x microscope lens if both are operated at 4X magnification because microscope lenses are designed to be diffraction limited at their specific operating point.

The microscope objective I bought cost less than $20. It was reviewed and recommended at a website that specializes in this sort of application. There is more info in a thread I started a while back: https://www.photrio.com/forum/threads/scanning-with-digital-camera-and-stitching.174808/.

Two big disadvantages of this approach are that it takes a lot of shots to cover the frame and that the stitching process can sometimes be dicey and give inaccurate results.