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Forum: Pentax SLR Lens Discussion 06-23-2019, 02:55 PM  
My old wide angles compared on Full Frame
Posted By Henrico
Replies: 4
Views: 1,243
Over the years I gathered lots of old glas for little money when they appeared on Marketplace. It seems many people got rid of their Pentax gear switching to digital Canons and Nikons. Now Pentax also offer decent full frame cameras the offerings on Marketplace dried up so I am happy to have my cabinett filled. These four lenses are my widest full frame lenses, I know how they behave on film and APS-C, I was just curious how they stand up on a full frame 36 Mp sensor. My back yard was an ideal test scene this morning with the rising sun from the left.

My quick observations:

Rokinon 14 mm F2.8 => Fits nice on the K1, balances well and is a real eye catcher. It suffers some mustache distortion, no real issue to my opinion. Amazing: This thing is equal clean and sharp at all apartures, even in the far corners it is sharp and shows only very little aberrations. Very usable already full open, it only vignettes up till F8. It is difficult to focus with this lens due to lower contrast full open. I also had to calibrate the focus scale using the 16x magnification function of the camera. Now infinity is infinity. Very nice lens for nature and indoor. For indoor use it is important to keep it straight horizontal/vertical to avoid disturbing perspectives.

Tokina RMC 17 mm F 3.5 => My oldest of these four lenses. Full open it shows low contrast and it is rather misty, avoid this setting. At 5.6 it offers decent center sharpness, only corner sharpness suffers unsharpness, fringing and coma. At F8 - F11 this gets more acceptable but it stays an issue. This lens also renders some flatter than the others do.

Pentax M 20 F 4.0 => Like all miniaturized M-lenses compared to their K-siblings this M20 performs very well on APS-C but less good on Full Frame. It offers very good (F4) to excellent (F8) center sharpness, it also has nice contrast, it renders briliant even with the sun in the frame and is very compact. Borders suffer a bit even stopped down and become acceptable at F8 - F11, far corners never live up totally. Anyway, this is a very usable lens, even on full frame. It looks like a dwarf on the K1 but in fact is a 40 years old masterpiece. My one looks like new without any dust in it.

Pentax A 24 2.8 => Apperture calibration is not OK, Av-setting results in overexposured pictures so I use it in the M/green button setting, then it works fine. This is a fine lens, already usable full open, it produces warm and contrasty pictures with only some purple fringing in the far corners.

In practice all four lenses deliver nice pictures used well. The Rokinon is a very good lens on full frame, only focussing is a bit difficult (low contrast) unreliable distance scale. The Tokina is very soft wide open and shows coma and purple fringing in the far corners. The 20 mm has a briliant contrasty center performance, the borders and far corners get acceptable at F8 - F11 but there still is some purple fringing even then. The 24 mm is a nice lens without any serious flaws, it already is usable full open.

Some full pictures now taken at F5.6, details (Full Open) are 200% and 400% expanded (F5.6 and F11)





















Forum: Film Processing, Scanning, and Darkroom 06-11-2019, 11:41 PM  
My best methodology for film scanning with RAW-camera
Posted By Henrico
Replies: 16
Views: 1,358
Before I used an old M-100mm F4 macro with an extension tube. Works fine with very nice results, manual focussing full open, stop it down to F8-F11 for the best results. Now I own the DFA 100 mm F2.8 macro with manual focussing. Because it is one stop wider the manual focussing goes more precise. Both lenses are more than sufficient for sharpness, they both out resolve your film.


I think 100 mm is to prefer over 35 mm from point of view for the more lineair perspective and shallow DOF. On the front top of the LED light bulb there is a little manufacturing rub that I removed with fine sand paper to achieve as equal possible light source. I kept some cm's distance between the bulb and the film so the uneveness of the bulb disapears in the shallow DOF. With a shorter focus length this might be more difficult to do.
Forum: Film Processing, Scanning, and Darkroom 05-27-2019, 02:13 PM  
My best methodology for film scanning with RAW-camera
Posted By Henrico
Replies: 16
Views: 1,358
Thnx for your replies. The road from shooting a analogue picture on film to a scanned view on your monitor is very interesting. First of all, I'm not an expert..., and I think the color management is very complex here.


Most of the times it is daylight illumination that lightens your object. Daylight is a more or less equal spread bound of wavelengths in the visual spectrum from 400 nm to 800 nm. Shooting pictures you project your object on a color negative film that is sensitive for three subtractive primary colors: yellow, magenta and cyan. When you scan this film, it is important the wavelengths of your light source correspondent with the three layers in the developed film. Best light source I think indeed is a clear blue sky with all the wavelengths in it. It will result in a complete spectrum of the illuminated exposed and developed film. LED light however is build up with specific bounds (or spikes) of wavelengths, in fact it is very unnatural light. It is a uncompleted spectrum. Warm white LED has a different spectrum than warm white halogen for instance… Warm LED also is cool lightbecause it consumes little energy. The sensor of your digital camera is sensitive for Red, Green and Blue. So this whole chain of components must result in a natural view on your screen, that hopefully is calibrated. Then there is the color space itself; sRGB, Adobe RGB and ProFoto RGB. Our the eye's retina finally consists these three different kinds of light receptors for red, green and blue. I started to get dizzy from this all, so I tried things out and stayed on what I liked most.


Illuminating your negatives with blue sky light absolutely will work fine, but here in the Netherlands we don't have that often those blue skies, it is difficult to do this reproducible, and most of time I do the scanning at winter evenings…


Using cooler light (higher K's) resulted to my experience to clipping oranges/reds due to the intensive blue transmission. But because LED light has those specific spectra, there might be a better fit with other bulbs than I chose myself (2700K).


Good to see more of you are experimenting in scanning, your pictures are nice too. I would like to learn from you to understand better what's all happening in this chain of conversions.
Forum: Film Processing, Scanning, and Darkroom 05-26-2019, 01:02 PM  
My best methodology for film scanning with RAW-camera
Posted By Henrico
Replies: 16
Views: 1,358
Ten years ago I started digitizing all my family prints, negatives and slides. For my prints that lacked the original film material, I used an Epson flatbed scanner, I cropped the photo's of the scan files with Photoshop and developed these to decent JPEGs. For all my thousands of negatives and slides I found a flat bed scanner disappointing, scanning is a lot of work and I choose to do it the best way possible. So I bought at ScanDig a brand new Nikon Coolscan V for € 900,- with SilverFast software to achieve what I had in mind. Nikon then already had stopped producing its scanners and prices were already getting higher and higher. In four years I scanned all my film material that I always had stored well organized, and I developed fine skills how to do that from 120 Mb TIFF files to decent 3-5 Mb JPEGS. The workflow started with Silverfast and was finished with Photoshop. During a scan (2-3 minutes) I did the digital processing of the former TIFF so there was no time lost. About two evenings a week I processed one complete film each. Four years later all my material was digitized, and stored in clouds, DVD's and hard disks and I used my Coolscan so seldom I decided to sell it. Buying, and not renting one had been a good decision, Coolscans were very looked after and I sold it for more than I bought it new...

But sometimes I still shoot film (Kodak Ektar) on my K2 and ME-super, just for fun, and my friends and family also know my skills on scanning... So I experienced how I could digitize these with my K-01. I found some info on the internet, but scanning color negative this way is pretty delicate to do. Choices for the best light source, blue filtering to neutralizethe red cast, white balance etc. resulted in a steep learning curve and I am happy now I found the right way to do it. The results are similar or even better than I achieved with my Coolscan, the digitizing itself goes rapidly fast, but the post processing takes more time, most for healing dusts and scratches. The advantage of the Coolscan is its Digital ICE; the pre-infrared scanning to identify dusts an scratches and repair this automatically with the Nikon software.
For anyone who wants to digitize its films I would like to share my experiences on how to do this in the right way. I only explain the procedure for color negative. Slide and B&W are rather easy to do if you own the skills for doing color negative. First of all; all the color information of your photo is captured in a narrow color space, so you must shoot RAW (16-bits) and develop in 16-bits. At the end you shrink to 8-bits and JPEG. My experience is that there is not more information on 35 mm film material than 10-12 Mpix, the resulting format is 3600x2400 or max 4500x3000. In my childhood I used to play with FisherTechnik. I still own it, now waiting for grandchildren, and I created a lay up with it for my scanning procedure. You can grab it for little on Marketplace here. The best light source is a larger Philips LED Bulb (18,5W 2700K), it offers equal warm white light and gets not too hot for the paper cilinder cover I use and the film itself. The light spectrum fits good with the color layers in the film and the RGB pixels on the sensor. I tried cooler light, blue filtering, tungsten light, but 2700 K LED is OK for the job.

I shoot RAW, the coolest possible manual White Balance (see picture below). Lens mounted is a 100 mm Macro (first M, later DFA, both are very good) at F8 or F11, ISO 100 and 1/500 - 1/1000. Nail the focus wide open on the grain in the film and be aware the whole spectrum in the film is covered in the histogram. I shoot with 2 sec timedelay to avoid any shaking, this is working good. Be aware of clean film stripsand take care during the shootings.

For the workflow of digitizing I use Photoshop / Camera RAW. Now the magic begins... Screenshots of how it works are shown below.
Upload the RAW file to your computer, open it in Camera RAW. I use CS5 by the way...
  • Crop the 3:2 frame, the histogram info shows just the info inside the cropped frame

  • Put the Temperature on 2000 K, Recovery on zero, Fill Light on zero, Brightness on zero, Contrast on 50

  • Now shift the "Tint" slider to the position that the blue channel in the histogram will be covered behind the other colors. Most that's nearby zero position. In fact you are compressing the histogram.

  • Finally adjust the "exposure" slider so the histogram expands to the rightside, and adjust the "blacks" slider to expands the histogram to the left side. What we are doing here is to expand the histogram as far as possible to get all the available information in full 16 bits color depth.

  • I always do some sharping in Camera RAW: Sharpness 50/1.0/2.5/0 , Color NR is 25 and Detail 50.

  • Now press on "Open Image", the 16-bits file will be loaded in Photoshop.

  • First thing I do is cropping it: 45cm x 30cm at 100 pix/cm, this results in a 4500 x 3000 pixels file.

  • To reduce digital noise and grain, choose Filter / Noise / Despeckle. This halves your file size without losing real sharpness.

  • Now invert your picture to positive; Image / Adjustments / Invert.

  • With the Levels menu you can make a brilliant picture of it; Image / Adjustments / Levels.
    • Expand for each color the histogram to full width (see screenshots) and press OK.

    • After that, tweak to good color balance by adjusting the central sliders for each color in the same histograms.

    • Not satisfied? Try to adjust the output levels under the histogram for each color, for instance, with the high Output Red you can cool a sky that is coloring toored. Press OK.

    • PS-experts; there are many more controls for the best results, I leave it here to the basics.


  • Now try "Auto Levels" and "Auto Color", sometimes this is the finishing touch, sometimes it worsens your result, then you undo it easily.

  • Finally pimp your result with some "contrast" and/or "vibrance" in your adjustments menu.

  • Remove dust, scratches and unwanted feet... with the healing brush tool in PS.

  • Now reduce by Image / Mode to 8-bits and save as a JPEG-file level 10.

First picture is the old original Coolscan-file, second one the recent result as described here. The Coolscan file is a bit cleaner due to the ICE-mode, the K-01 scan is more crisp and shows no halos. The Coolscans sometimes does show linear halos (line-sensor) near clipping contrasty areas. When you get used to this procedure, and you own some PS-skills, scanning with a RAW camera really goes fast. Most work is caused by restoration of damaged film and dirty sensors. Because you are expanding the dynamic range so much and use small lens opening, you will see every anomaly in blue skies etc.

My youngest son's face is expanded to 100% to see the difference, the left one is K-01 scan, the right one the original Coolscan. The boy has grown now over 1.90 meters...

I hope this is helpful and useful for you, please reply your improvements, I am still in a learningcurve... Thnx!



Coolscan first, K-01 scan second:






































Forum: Pentax Medium Format 04-04-2016, 12:05 PM  
645Z owners: Will you switch to a Sony 75MP A7RIII?
Posted By Henrico
Replies: 79
Views: 7,234
You can get as much as detail as desired. Take several pictures beside/above each other at exactly the same settings (ASA, shutter, and sweet-spot opening) in RAW and devellop to one super sized picture.


Works fine!
Forum: Pentax K-01 03-25-2016, 02:58 AM  
Hoodman makes K-01 awesome for manual focussing
Posted By Henrico
Replies: 14
Views: 2,459
This all works fine and nice. I use my K-01 with many K/M/A lenses, up to 400mm. It came with the XS40, what is a real nice lens also. Most legacy primes excel only stopping one step down. I really have no problem in focussing at F1.4, or long tele's. Tack sharp, only beware: there is some delay on your screen, it's not a OVF. Always wait a second or so to be sure that what you see is really what you get.
Forum: Pentax K-01 03-25-2016, 02:19 AM  
Hoodman makes K-01 awesome for manual focussing
Posted By Henrico
Replies: 14
Views: 2,459
In the Netherlands available now for €139.... I thought I paid less but I'm not sure.

Hoodman Cinema Kit
De Hoodman Cinema Kit maakt het filmen met een DSLR eenvoudiger. De kit bestaat uit de HoodLoupe 3.0, HoodMAG 3.0 en Cinema Strap. Hiermee kunt u het LCD-scherm gebruiken als viewfinder. De kit is geschikt voor schermen tot 3". De HoodLoupe zorgt ervoor dat u op het scherm kunt kijken zonder dat u last heeft van schitteringen. U kunt de dioptrie hierbij aanpassen tot +/- 3. De meegeleverde eye cup kunt u op het oculair plaatsen om zo een 3x vergroting te bewerkstelligen. Met de Cinema Strap houdt u de HoodLoupe op zijn plaats, zodat u beide handen vrij hebt om de camera te bedienen. De behuizing en het oculair zijn gemaakt van rubber, wat het draagcomfort vergroot en bescherming biedt tegen schokken.
Inhoud van de verpakking:
- HoodLoupe 3.0
- HoodMAG3.0
- Cinema Strap
Forum: Pentax K-01 03-24-2016, 09:34 AM  
Hoodman makes K-01 awesome for manual focussing
Posted By Henrico
Replies: 14
Views: 2,459
Just transparant silicone kit. Never use super glue or so! Silicone kit works fine, good adhesive and if necessary removable. You can simply remove the last silicone with your nails when you remove the hood. So it is a reversal solution.

I bought the hood 2 years ago, search for Hoodman Pro, the optics are multicoated and adjustable by turning the occulair.
Forum: Pentax K-01 03-24-2016, 04:30 AM  
Hoodman makes K-01 awesome for manual focussing
Posted By Henrico
Replies: 14
Views: 2,459
Recently glued my Hoodman on my K-01, looks odd but works fantastic! So I got rid of the elastic bandings. Result is a very stable camera (eye + hand contact), superb and bright 1K EVF, 6X digital zoom for nailed focussing and a bright view even in heavy sunshine! The Hoodman offers very good "German" optics for just 139, my K-01 now is a manual prime killer in all circumstances... Nothing wrong with this old stuff! :)
Forum: Pentax SLR Lens Discussion 09-26-2015, 12:56 PM  
Dissambling A 400 5.6
Posted By Henrico
Replies: 4
Views: 1,989
I got some advice from an expert, he told me to cut two 2mm slots with a grinder at the front tube, so I could put much more force to unscrew. I fixed the other side with duck tape and a screwdrawer and still needed WD40 to make it going.


I cleaned all with pure alcohol, removed the oil and fungus, and now it's clear as new....!
Forum: Pentax SLR Lens Discussion 12-28-2014, 07:07 AM  
Dissambling A 400 5.6
Posted By Henrico
Replies: 4
Views: 1,989
I became this far, the fungus is in between lens 2 and 3, especially at the center aerea where 2 and 3 are allmost in contact with each other.

I tried to unscrew the fronttubeout of the outer tube, the front tube is reaching a just few mm out of the sun cap when it's not extended, but it seems locked very tied. I do lack any grip to force it.
My thoughts are it must be possible to remove the sun cap but it's cought around the tube.
There seems no screwing rings in the inner part of the tube.

Has anyone the right suggestion for me to get in between 2 and 3 ?
Forum: Pentax SLR Lens Discussion 12-23-2014, 08:32 AM  
Dissambling A 400 5.6
Posted By Henrico
Replies: 4
Views: 1,989
I own this 400 mm for a while, and noticed the 2nd or 3rd elements from the front side have some fungus. I removed the front element, but that does not give me entrance to the affected surfaces.


Has anyone experience in disassembling the front side of this objective?


There are three tiny x-screws at the tube in the middle, but they are too tied to unscrew withoud harming the inner profile.


thnx


Henrico
Forum: Pentax SLR Lens Discussion 10-26-2014, 04:21 AM  
Misty 24mm.... Oil or Fungus ?
Posted By Henrico
Replies: 16
Views: 2,121
Hi you all,

I bought me a lens spanner from China and disabled my lens as described.

There was some oil on one lens surface but the biggest problem indeed is lens separation in the group elements. I suppose that's not easily fixable.

So it definitely now has become my 2.8 soft lens....

Thnx for your advice!
Forum: Pentax SLR Lens Discussion 09-03-2014, 12:33 PM  
Misty 24mm.... Oil or Fungus ?
Posted By Henrico
Replies: 16
Views: 2,121
Thanks Alex,

Yesterday I tried to open it up from the front side. I easily removed the name plate and started unscrewing the three tiny screws. Two of those went easy, one did not cooperate and I ruined that screw. I tried to drill it out but that was more difficult than I thought it was so I left it....

Question to you; is it necessary to remove those three screws to remove the front group, or do I only need to remove the narrow ring around the group? I tried to do that with two screwdrivers but failed to unlock it. So I doubt what to do now...

Don't pay attention on the dust under the front lens, I removed it to inspect those surfaces and they were not affected, I cleaned them quickly with a tissue but I have to repeat that with a dust free handkerchief .
Forum: Pentax SLR Lens Discussion 08-27-2014, 02:34 PM  
Misty 24mm.... Oil or Fungus ?
Posted By Henrico
Replies: 16
Views: 2,121
Thanks for your advices!

A closer inspection of both sides of the lens in bright light with a magnifier shows there ar obviously two different surfaces infected, one in the front-group, one in the back-group. So I get pretty convinced it is condensed oil, it looks as many tiny drops on the glass. Last year I cleaned the blades of my M 35mm f2.0 and those inner lenses also were a bit affected with condensed oil.

So I'm best gonna buy me a lens spanner, try to remove the front group in one part, to reach the inner elements close at the blades and clean them up. Has anyone experience in disassembling this lens?

Despite some reservations on the lens reviews I am pretty impressed by the sharpness this lens produces already now. It's close to my 28 mm K. This 24 mm also has a very nice look & feel, it's more a "M" than a "K", so I definitely will adopt it in my collection of old full frame glass....
Forum: Pentax SLR Lens Discussion 08-26-2014, 09:05 AM  
Misty 24mm.... Oil or Fungus ?
Posted By Henrico
Replies: 16
Views: 2,121
Fortunaly not that much. I think I will keep it and might use it for special morning misty effects....

The two garden pictures were taken with sunshine straight in the lenses, to express the extreme flare effect. Avoiding that this little beauty produces soft but tack sharp pictures one stop down...
Forum: Pentax SLR Lens Discussion 08-26-2014, 08:21 AM  
Misty 24mm.... Oil or Fungus ?
Posted By Henrico
Replies: 16
Views: 2,121
Bought me an oldie goldie, the K24 f2.8, which looks obviously mint with super clear outer glass. Unfortunately it suffers of flare caused to two inner elements close to the blades. A closer inspection makes me think it's oil, the structure of the pollution is pretty uniform, as if it's sprayed over the surface. The bigger outer lens elements seems very clean to me. It's very good visible shining a bright light straight through the lens.

What's your opinion on this? Dissasambling and cleaning with isopropanol?
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