150mm Printing-Nikkor 1/4-4X version

Sager · Post by **Sager** » Fri Nov 09, 2018 3:19 pm

Greetings!

I have the floating optics 150mm Printing-Nikkor (1/4-4X) en route to me now. I wanted to query the community on experience with this lens and see if anyone can confirm my suspicions on the quality and image circle.

Based on coinimaging tests up to around 1.4X the corner sharpness improves quickly as magnification increases. Also, resolution seems to remain outstanding up to the tested ~1.4X.

Based on the information available online it would seem this lens was designed for converting various film formats and based on conventional wisdom the image circle should grow as the magnification increases.

I made the image below based on the standard film sizes.

If we take the sharpest aperture to be f3.3 (based on coinimaging results) the effective aperture at different magnifications would be (based on 1+Mag x fstop = effective aperture)

Using 5um pixels as a baseline for when diffraction sets in, I get these results:

@f3.3
1X / 30mm IC: f6.6 (below diffraction limits for ~5um pixels)
2X / 60mm IC: f9.9 (below diffraction limits for ~5um pixels)
2.3X / 70mm IC : f10.89 (right at diffraction limit)
3X / 90mm IC : f13.2 (diffraction sets in)

If f2.8 maintains quality at higher magnifications then the results would be:

@f2.8
2X / 60mm IC : f8.4 (below diffraction limits for ~5um pixels)
3X / 90mm IC : f11.2 (right at diffraction limit)
4X / 120mm IC : f14 (diffraction sets in)

Wondering if anyone has real world experience with this lens that might manage my expectations on what tests to pursue when the lens arrives. I currently have a Phase One IQ150 (44x33 sensor @ 5.3um pixels) but am thinking of getting the 100MP or 150MP Phase One sensor when I can afford it - if the quality holds at higher magnification and larger image circles it would make this lens stand out even more than it already does.

ray_parkhurst · Post by **ray_parkhurst** » Fri Nov 09, 2018 5:59 pm

Will be interested to see your test results when the lens arrives!

I have always avoided this lens due to the small published image circle, and the required extensions due to long FL. I complain about the 105IXL needing 15" extension for 3x, but the 150PN would need 22" or so! Would be great if it was a strong performer at 3x at f3.3 (or f2.8!!), as there seem to be few high resolution / long WD options at that mag. Perhaps I will change my mind about the lens if your tests show good coverage and IQ.

Sager · Post by **Sager** » Fri Nov 09, 2018 9:39 pm

Hey Ray!
One thing to remember is the Printing-Nikkors have non-standard calculations for back focus.

The 105mm PN has a back focus of 55.1mm at 1x and the 150mm PN has a backfocus of 74.5mm at 1x. About 1/4 the rough calculation of 2x focal length for 1:1 on most lenses (and strangely about the half the focal length). If this remains consistent the bellows draw for the 150mm would look like this:

1X : 74.5mm
2X : 149mm
3X : 223.5mm
4X : 298mm
5X : 372.5mm (out of optimized range)

If I use the focal plane shutter on the Phase One XF body (with a flange to focal plane of 63.3mm) I only need these extensions:

1X : 11.2mm
2X : 85.7mm
3X : 160.2mm
4X : 234.7mm
5X : 309.2mm (out of optimized range)

An easily achievable range on most bellows with a few extension rings at higher mag.

Focusing by sensor you could achieve these ranges starting with the minimum image circle of the format and matching it to the magnification (@ max quality if you take the trouble to automate the float ring like Nathan did for the Rayfact and Macro Varon)

@DX format you could sweep 1x-3x w/ ~150mm rail travel
@FX format : 1.5x-3.5x w/ ~150mm rail travel
@65mm Cine (44x33 digital) : 2x-4x w/ ~150mm rail travel
@IMAX (larger than full frame 645 digital) : 3x-5x w/ ~150mm rail travel

However with the extended working distance of 150mm FL I wonder if focusing by rail on a deep stack would be better??? Plenty of working distance to not crash your lens in to the subject... Perhaps Rik has an opinion...

Interestingly if you look at the Rayfact specs on the new 1-2X floating optic 105mm lens and the 2-5X 116mm (that Nathan picked up) the original Printing-Nikkors had about half the back focus distance at similar magnifications:

ray_parkhurst · Post by **ray_parkhurst** » Sat Nov 10, 2018 8:40 am

Be careful about interpreting those diagrams. The most relevant number is the "Flange Focal Distance", which is 123.5mm for the 150PN. This gives the basic extension required for infinity focus, but you still can't use this number for calculating the extension required for higher magnifications. For this you must use the actual focal length of the lens. So the Total Extension (TE) table should be:

TE at infinity: 123.5 (which is the published FFD)
TE at 1x: 273.5 (FFD + FLx1)
TE at 2x: 423.5 (FFD + FLx2)
TE at 3x: 573.5 (FFD + FLx3)
etc

In the doc that shows the diagrams you published, there is another useful spec..."Overall Working Distance", which is stated as 573mm at 1x. This is basically twice the TE at 1x. The full page is shown below:

Sager · Post by **Sager** » Sat Nov 10, 2018 3:20 pm

Ahhh, thanks for the correction!!! I didn't know the old spec sheets reference flange to focal distance at infinity.

The newer Rayfact drawings all have the flange to focal distance at the rated magnification.

I just put a 105mm Printing-Nikkor A-version on my test setup and quickly lined up a 1:1 target. I roughly measured ~188mm which is close to Rayfact spec sheet for the 1X Printing-Nikkor, they quote it at 189.8mm.

Using your correct formula you arrive at a very similar number for the older 105mm PN in the spec sheet : (FFD + FLx1) = TE @ 1x

105mm + 85.2mm = 190.2mm

Thanks again for the correction Ray!!!

These numbers make way more sense:

TE at infinity: 123.5 (published FFD)
1x: 273.5 (FFD + FLx1)
2x: 423.5 (FFD + FLx2)
3x: 573.5 (FFD + FLx3)
4x: 757.5 (FFD + FLx4)

So, a 2X-4X sweep moving the sensor would require rail travel of 334mm...
Actually doesn't sound too bad to me. The bellows on my Linhof M679 view camera has around 325mm of bellows travel. The camera is not motorized (yet) but it would be easy to mount this lens on the Linhof and at least have a manual adjustment range that covers the magnification range of the lens. The whole Linhof M679cs could then be put on a motorized actuator for focus.

For focus stacking, focus by rail (versus sensor) starts to sound much more practical at these extensions.

Sager · Post by **Sager** » Thu Nov 15, 2018 10:58 am

Received the 150 PN variable last night. Confirmed that Ray's extension calc's were correct (no surprise).

What was interesting was that the IC at 1:1 on a 44x33 sensor was not as bad as I thought it would be... I had a 150mm PN fixed 1:1 for a brief time, the lens had very bad astigmatism (radially smeared details) outside of the ~30mm IC at 1:1 - I sold the lens because of the very limited IC. IMHO the 105mm PN is a much better 1:1 lens than the fixed 150mm (old version).

The 150mm variable 1/4-4x is a totally different beast. At 1:1 the corners are soft but not suffering from typical aberrations. By about 1.25-1.5x the corners get much better on a 44x33 sensor (especially stopped down to f4). I see the primary utility in this lens from 1X-2X where it's incredible working distance is a huge asset. For my work I also love the compression of the long focal length and the ability to choose which portion of the image on a deep stack that I want to optimize for. For my miniature landscape photography, loss of resolution at lower magnification is not necessarily a bad thing as it can mimic the loss of contrast caused by atmosphere in a normal landscape photo. So if I have a foreground at 1.75X I can optimize my image stack so the foreground is sharper and that quality decreases as the magnification decreases.

I found a M72 tube from a machine vision setup that happened to fit the 150mm perfectly - this started me off with about ~250mm extension that made it easy to sweep the range of 1X-2X with 150mm travel focus actuator.

So far, I have found that there are at least three distinct models of 150mm Printing-Nikkor:

Version A: 150mm Printing-Nikkor 1/4-4X ~30-86mm IC
Version B: 150mm Printing-Nikkor fixed 1X ~30mm IC
Version C: 150mm Printing-Nikkor fixed 1X ~86mm IC

While researching the 150mm Printing-Nikkors I got in touch with the Technical Director at Fotokem. He was able to confirm the lens they used for IMAX transfers (IMAX and 65mm 5-perf film for Christopher Nolan's Dunkirk was processed at Fotokem for instance). There is a newer version of the 150mm Printing-Nikkor that has a 86mm image circle which is the primary "off-the-shelf" lens for IMAX 1:1 film printing. This is the only model Printing-Nikkor with a large image circle other than the variable model which only reaches this IC at 3X. BTW: The specs on redbook are for the newest 150mm PN from the early to mid 1990's even though the pics are of a variable model from the 70's/80's. I have the feeling this is the source of some of the confusion around image circle for the 150mm lens.

Version A (150mm variable I just received):

Version B (previous 150mm that I owned):

Version C (from Fotokem):

ray_parkhurst · Post by **ray_parkhurst** » Thu Nov 15, 2018 6:23 pm

Good info on the different versions. Will be interested to see an aperture sweep around 3x to see how well this lens could work for stitching on FF.

Sager · Post by **Sager** » Tue Jul 16, 2019 11:41 pm

I finally found the newer 150mm Printing-Nikkor with the 86mm image circle... Now I just need to find time to mount it and test it out... In fact I still haven't really shot with the 1/4X - 4X version though I did figure out a somewhat makeshift mounting solution for it. Too many lenses, too little time...

For any Phase One XF users out there... To be honest I've been shooting a lot with the Phase One 120mm LS Blue-Ring lens. The XF body supports automatic stacking with this lens in the camera body (also factoring in the aperture setting to optimize the shot count with the proper overlap between frames). The SK 120 BR shoots from infinity to 1X and is pretty good, unbeatable for efficiency when you factor in the optimized native focus stacking. No wasted frames on a deep stack. Resolution on the lens is great but CA is only OK.