Tuesday, February 6, 2018

Sigma 18-35 F1.8 "ART" focus issues

Some years ago, I bought a Sigma 18-35 F1.8 "Art" lens for my Pentax K-5II and, besides its huge size and weight, I liked it very much.

It's a very high optical quality lens for an unbeatable price. Image is tack sharp from edge to edge even at maximum aperture. At least on the K5-II.

Things started to be strange when I got my K3-II and I noticed that the lens was not sharp in any aperture larger than F4 independently of the focal length. Wow. Something was smelling bad.

I put the lens back on the K5-II and it worked without any problem. Was my K3-II faulty ? I checked it with three Pentax DA lenses (40, 50 and 70 mm) and besides a very slight front focus in the 70mm that I corrected by the in camera AF micro adjustment, everything was tack sharp and the focus dead on. So the problem was, at first, not the camera itself.

Then I decided to use the Sigma USB dock to fix the focus issues. Camera on a sturdy tripod, a measuring tape, a focus target and everything else needed.

I used the live view and the central AF point for the adjustments and for my surprise, all pictures came in perfect focus ! Strange. I took the camera and shot some random pictures at maximum aperture and... Some of them were out of focus.

To keep things short, the camera was missing the focus when the optical viewfinder was in use and making it dead on when using the live view.

This of course has to be something to do with the contrast and phase focus detection system.

After some DAYS wrestling with this lens and the USB dock I managed to get it working in a decent way.

There are lots of reports about this lens causing issues on Canon and Nikon bodies with the lateral focus points.

There are no real information from Sigma about what's the cause or if is it fixable by a lens or camera firmware update.

My advise is to TEST this lens in your camera before buying it. If it works well, you'll get by far the best lens on its class. If not you'll get a very frustrating and expensive paper weight.

I found a good article here about this.

Sunday, February 4, 2018

Konica Hexar Silver

Konica Hexar Silver

Konica Hexar Silver

Top controls

This is one of greatest film cameras of all time. It's wonderfully made and maybe the most silent 35mm camera.

It's a multi mode autofocus camera with Program, aperture priority and manual exposure modes. The viewfinder is very large, clear and distortion free, with three exposure and a focus confirm leds.

The Hexanon 35mm F2.0 lens is superb in all aspects, razor sharp even at full aperture. The only drawback is the maximum shutter speed of 1/250s at maximum aperture.

Sometimes you can find one at e-bay, but expect to pay a high price for it.

The optical performance is comparable with a Leica Summicron 35 but for a fraction of the price.

I said before it's silent ? It's very silent. Seriously. It's a perfect camera for street photography and also my personal pick for travel light.

It has all the possible modes you need, exposure compensation, sport metering and a very sophisticated autofocus system. I don't remember about having a single out of focus or bad metered photo with this camera ?

I think it's a much better deal than any Leica with a 35/2.8 Summaron. It simply does better and cheaper.

Wednesday, November 29, 2017

The Nikon "universal" mount. Not so fast !

Before some people start to go crazy about what I wrote, be advised that I have used Nikon for years. From Nikkormats to D800. So just relax and read before raging against someone who dared to say something against your god. =) 

Nikon and a huge legion of its users and fans always keep saying that Nikon has the most backward compatible lenses and mount system on earth. Wrong. Very Wrong.

The Nikon mount system is a total mess:

- Pre Ai lenses (prior to 1976)
- Ai and Ai-S manual focus lenses with aperture ring
- AF lenses with and without built in motor
- AF lenses with and without aperture ring
- Full frame and APS size sensor sizes
- Cameras with and without aperture ring
- Cameras with and without built in AF motor

- Coupling "horns" of two types

The real fact is that Nikon has no total backward compatibility and even worse, even lenses and camera bodies from the same year may not be compatible. The nikon mount is a mess by definition. Some lenses can even damage some bodies if you try to fit them together. What was supposed to be good can turn into a real nightmare and waste of time and money.

Lenses from 1959 to 1976 are the original A mount type. They can't be mounted in ANY Nikon body except pre-Ai bodies and the ones that have a foldable aperture index tab on aperture coupling ring, like the flagship Nikon DS. 

If you try, for example, to fit an old Nippon Kogakku 50mm F1.4 from 1970 (excellent lens by the way) , and if was not not modified to Ai, on ANY camera without the folding tab you may break the body's aperture coupling ring and stuck the lens on the camera mount.

There are two types of autofocus lenses, with the AF motor built in the lens itself and without it. Lenses without motor won't AF on camera bodies without AF motors. 

For example:

The D5XXX has no AF motor on the body neither the aperture coupling ring. You can use AF lenses with motor and Ai/Ais manual focus lenses that have electronic contacts. No contacts = no light metering.

The D7XXX has AF motor and the aperture coupling ring. You can use all lenses on it , but *NOT* old "Pre Ai" lenses.

There are even lenses with and without aperture ring. You can't use any lens without aperture ring in any non AF nikon, for example, the FM2. The FM2 will accept just Ai/Ai-S lenses or AF fullframe lenses with aperture ring.


- If you have an OLD Nikon like a Nikkormat you need a pre Ai lens with the famous "horns" to couple the lens aperture ring with the camera aperture ring. 

Be advised that there are TWO "horn" types and they're not compatible and mounted in opposite ways.  Pre Ai lenses have the aperture coupling "horns" facing to the lens front. Ai and later lenses have it facing backwards, to the lens rear. If you plan to use an Ai lens on a pre-Ai body you need to reverse the horn orientation to have the proper coupling.

Nikon Pre-Ai coupling "horn"
Nikon Ai coupling "horn"

- If you have a camera like the FM, FE, FM2, N2000 you need an Ai / Ai-S or pre-Ai converted to Ai lens, with aperture ring for proper metering.

- For autofocus cameras like the D40 to D70 and D5xxx you can use AF lenses with or without aperture ring but you need the AF motor on the lens to have autofocus. You need lenses with CPU for proper light metering.

- If we're talking about high end autofocus cameras like the D600 and D7xxx you are allowed to use all nikon lenses but NOT pre-Ai ones, unless they were converted to Ai. Those cameras should work with all AF lenses, with or without autofocus motor and aperture ring.

- Finally if your camera has a foldable tab on the aperture ring, like the Nikon DS, you'll be able to use any kind of Nikon mount lenses on your camera. This tab purpose is to allow the use of pre-Ai lenses.

If you want a really universal SLR system, go for Pentax. All K lenses work on all K bodies and you have an extra bonus, can also use all M42 screw mount lenses on a Pentax K body with a small and cheap adapter.

Funny fact: Any Canon EOS and any Mirrorless system with the proper adapter can properly exposure meter with any Nikon lens with aperture control ring. Just set the camera to aperture priority. Sorry but the Nikon F mount sucks.

Saturday, October 14, 2017

Pentax Espio Mini

The Pentax Espio Mini is probably my favorite compact camera.

It's a very tiny 35mm autofocus camera fitted with a very high performance 32mm F3.5 lens. It's beautifully coated and capable of jaw dropping images. It can easily fit in a pocket.

The autofocus is fast an precise and the exposure is fully automatic from 2s to 1/400s, and there's even a B setting (but no external cable release!). It also has a slow sync mode for night shots.

There's a panorama 16:9 crop mask that can be used to create pseudo panoramic images. 

Thursday, October 12, 2017

Fujifilm X-TRANS processing workflow - Part 1

This is not a review. Just some short comments about the most important programs that can handle X-Trans raw files.

Updated on October 11th, 2017


X-Trans raw files are a pain to process. Really.

The complicated nature of its non standard demosaic algorithms are a real nightmare for both users and developers. 

From the user side, there are just a few programs that are able to extract the full potential of this new class of color matrix, and all of them, besides the awfully complicated RawTherapee and Fuji's OEM version of Silkypix are paid and usually expensive.

Things aren't different from the developer's point of view. There are almost no technical information about the mathematical methods for the decoding process, and many of the amazing sharpen and noise reduction algorithms used be well known programs just can't cope with nothing else than the traditional Bayer pattern. That's why, for example, DxO just gave up on any non Bayer sensors.

These are my own opinions based on my experience and needs. Of course opinions can vary from people to people.

The most practical options on market due this day are:


It's a very powerful software and probably the best one in terms of extracting the highest detail from the raw files. It's really good on this and also on noise reduction and film profiles. The price is fair.

The drawbacks are a horrible interface and it's slow. By horrible and slow I meant really horrible and slow. Its features are sometimes hidden in non obvious places and I never managed to find how to apply setting on a group of images in real time. I suggest you to try to do this.

But it's the best program if you want to have extremely detailed images from the X-Trans sensors.

Don't forget to download the film simulation profiles.

Pros: Generally very good results if you don't need to push too much sharpness.

Cons: Annoying interface and SLOW. Sometimes the sharpening adds funny artifacts that looks like noise.


It's a stripped down Silkypix 4. It's free, so don't complain. =)

The interface is way better than the previous program but still have some serious problems with (maybe) the Japanese to English translation. Some terms are just too weird.

The overall results are pleasing but it's slow like hell. Can be upgraded to the las SP Pro version for $150. Not a cheap upgrade, but not awfully expensive.

Not recommended. It's slow like continental drift.

SILKYPIX 5,6,7,8

The 8 Pro is a solid program, but the full price is in my opinion too high, about $250. 

The good thing is that it has support for the camera's built-in film simulation profiles. The sharpen algorithms are very good and way better than the equivalents found on Photoshop, Lightroom and Capture One.

They offer upgrades for several OEM and previous versions for a reasonable price, from $250 to $100 in some cases. Worths checking.

After using SP 8 Pro for more than one month, I'm very impressed with the final result. The sharpen and noise reduction are maybe the best for X-Trans and the colors are far more accurate than any other competitors.

Pros: Just one program, generally good results IF you find out how to master the sharpen and noise reduction process. Image detail can be much better than Lightroom, Capture One and even Iridient.

Cons: You really need to read the manual. There are lots of "hidden" important features.

Forget about any version lower than 7 Pro. 


It's free, fast, well documented BUT it's by far the most complicated image processing program I've ever used in my life.

The sharpening and noise reduction functions are overwhelming and extremely comprehensive. Curves, color and histogram operations unfolds on many, many variations enough to make you scream when you see them for the first time.

The results can be awesome if you don't go nuts using it.

Pros: Can deliver stunning results and There are really good film simulation profiles for it.

Cons: Extremely complex and you need do be cross between a Zen monk and a Image Scientist to master it. Not kidding. 


Well, they work but honestly their raw engines are not a match for neither one of the above mentioned programs and they are very expensive for what they are. You need to do a true olympic marathon in adjustments to get "near" the image output from the other ones, so I won't even comment them. I just gave up on them.

Capture one is a solid option, but a bit pointless for a X-Trans camera. It handles X-Trans files reasonably well, but there are better options for less than the $300 they ask for it. The only reason I can imagine to buy it is IF you're a very heavy C1 Media Pro user AND also use a Canon or Nikon camera in tethering mode, otherwise is a complete waste of money. I've tried it by 60 days and I was not convinced.

Lightroom is almost a religion, and forgive me fanboys, its X-Trans support still  sucks in plain 2018 and I would never, ever use a subscription based software. It will be a money sink in the long run, just do your calculations and check by yourself.


This was a surprise. Its raw engine is still under development but I got some interesting results from it. I have to do some more experiments before giving it an honest rating.

There are many third party photoshop plug-ins that will run on Affinity. It's also compatible with Nik's collection.

Pros: It's FAST and good. Compatible with Nik collection, DxO Film Pack and Noiseware Professional plugins from Photoshop.

Cons: No film profiles

Apple Aperture

If you're an Apple user and still have Aperture installed and updated, it is capable of very good results, pairing even with Iridient. Images tends to have less noise. You need to add the raw fine tuning  control.

The raw engine is OS dependent, so it will support all cameras supported by Apple Raw Engine. Those updates are OS updates, not Aperture's.

For film simulation, I use DxO Film pack Aperture plugin. The response is a bit different than Silkypix's but I'm very pleased with it.


Pros: Very nice final look with good colors and well controlled sharpness. Compatible with Nik collection, DxO Film Pack and Noiseware Professional plugins for Aperture

Cons: Aperture reached end of life development. It still works on MacOS High Sierra but who knows the future. No film profiles.

Bottom Note:

In the end, after some years using the X Series, theX-Trans matrix doesn't appears to make any real improvement over a Bayer (without the AA filter) besides maybe some higher detail on high frequency zones. But the Fuji's package is very powerful considering the price and final result. Still a very good and solid option.

Fuji always liked to try some different approaches on sensor design, like the Super CCD and its numerous incarnations and I respect this. At least, like Sigma with the Foveon, they try.

Soon: Some examples using Iridient Developer, Silkypix, Capture One and Aperture. 



Monday, October 9, 2017

Olympus 35RC

This is a very nice and compact 35mm film camera.
It has two operating modes, shutter priority and full manual.

Olympus 35 RC

I got mine for $35 and it just needed a viewfinder and lens cleaning. The meter and mechanical parts were perfect. I also ordered a custom made light seal kit from Aki-Asahi. Their light seals are very well made and affordable.

The camera has a top shutter speed selector on the top plate and it's possible to choose from 1/15s to 1/500 plus B. It's a fairy limited range but it's amazing how you can do if combined with a razor sharp five element E.Zuiko 42mm F2.8 objective and a good 400 ISO film. 

The lens is EXTREMELY sharp at F5.6 and F8 and still a very good performer at F3.5 with some corner softness at maximum aperture.

Focusing is done manually by a nice coincidence image rangefinder. The viewfinder is very clear (when clean) and shows the selected speed and the calculated aperture.

The shutter priority mode needs a battery to work. The original one is a PX-625 1.35V mercury battery, now banned, but you can use a Zinc-air Wien battery and it works very well. Another option is to adapt a silver oxide battery (1.55 V) and have the light meter recalibrated by a technician, or just compensate the difference selecting a higher ISO. I do not recommend 1.5V alkaline batteries as the voltage drops during its life time. The difference from 1.35 to 1.5 V can result in a +2 stops exposure error. 

Finally I ended with a very nice voltage converter adapter. Worth every cent.

The manual mode is meter blind. You will need an external light meter or an exposure table to properly expose the film. It's possible to use the manual mode without the battery.

Also very interesting is the "Flashmatic" system used on several Olympus cameras from this era. It's a very clever approach. The idea is to set the camera with the flash guide number (luminous power) and the camera will automatically set the aperture based on the film ISO and focusing distance. Works like a charm and it's not fooled by the background. It can sync in any speed.

The CdS light meter sensor is positioned inside the filter thread, allowing automatic compensation for the filter factor.

It's a very precise meter and capable of good exposures even with positive film, but remember it's center weighted, so you must compensate manually for strong backlight or the classic bride on the snow and black cat in a coal mine situations. The shutter release also acts as an exposure lock when pressed half way.

And last but not least, the filter size is 43.5 mm, and not very easy to find. Like many other people, I decided to use a 43.5 to 46 mm step-up ring.

There are much more information about the 35RC  on the following web sites :

Andrew Yue website
Camera Quest
Compared to other Olympus cameras with rangefinder from the same era:

This RD is a much better than the classic Olympus Trip 35 and, in my opinion a better choice than the Olympus 35 DC. The later one has a more luminous lens but it's totally autoexposure within almost the same exposure parameters with the shutter speed range from 1/15s to 1/500s and a 40/1.7 lens. The manual mode of the RC is a killer difference.

The best one from the series is the RD. Think about a RC with a huge 40mm F1.7 lens and a mechanical shutter capable to go down to 1/2s. This little camera is a killer. It's also smaller than the Canon Canonet QL17 and QL19. But the RD is a rare camera and usually expensive.

Compared to the XA, it's much cheaper, has a better viewfinder and rangefinder and less prone to electronic malfunctions. I think the RC lens is sharper than the XA's one.

The 35SP has superior specifications in almost every aspect, but it's a much larger and heavier camera and the light meter sensor is placed outside the lens filter tread and you need to remember to compensate if you're using filters.

Thursday, October 5, 2017

Kodak Retina IIS

The Kodak Retina IIS (Type 024) is a simpler camera if compared to the IIIc (type 028). It's not a folder and it can't have the front lens group of the objective changed to make a wide angle or a telephoto lens. The IIIS (type 027) is like the IIS but like the IIIc has an interchangeable lens mount.

Kodak Retina IIS
The photo sucks, I know and I'll change it when I have time. 

Like all Retinas, it's made in Germany by Nagel. It's a sturdy camera, but, oh boy, its project has some stupid complications, like coupled aperture and shutter speed controls aka LVS. When you change the speed, the aperture is also changed to keep the same exposure. This is really annoying. Also terrible is the very primitive "auto" exposure control. To be honest, it's better to ignore it and do everything manually. Curious ? It's something like this: 

1) Set ISO properly by a very strange system, keep pressing the button at the top of the light meter assembly and turn the aperture setting at the camera bottom simultaneously until the right iso matches the index. You need to repeat this every time you use a different ISO film

2) Choose a shutter speed

3) Now point the camera to whatever you want to photograph and check the meter needle position. Then turn the aperture adjustment control (bottom of camera) until a white triangle matches the meter needle

4) Ta-daaahhh the camera now has the correct speed and aperture settings needed for the moment.

Really ? Just get a hand held light meter and be happy.

Not to mention the mechanism needed to do this is extremely complicated and prone to break.

Resuming Retinas: Very good optics but dreadful mechanics and very stupid   complications.

The selenium light meter is linked by an intricated cables and pulleys system to couple it to the aperture control. To be honest, forget it exists. The selenium cell is almost certainly dead by now. If one of those strings break, the aperture/shutter mechanism almost certainly will be jammed.

Like the IIIc and many other Retinas, the film frame counter is a nightmare, some sort of a sadistic joke from the designers. I'll not dive into details, better check the manual and see by yourself.  More information on Camera Quest (IIIS). 

Quoting Stephen Gandy from CameraQuest:

"The film counter is among the worst ever designed.   My theory is that it was really a CIA experiment to find out how long it would take to drive Photogs insane.  The film counter is manually set by 1st pushing down on that little button besides the film counter, and then moving the nearby chromed button on the back side of the top plate in the direction indicated by the arrow.  Each push resets counter 3 frames at a time.   That's right, 12 pushes are required for 36 frames, lovely, just lovely.   The frame counter shows how many exposures are left on the roll, counting DOWN to 1.  It then LOCKS, forcing you to stop and either reload the film, or re-set the film  counter to get that extra shot on the roll.  Arrgggh. - Stephen Gandy - CameraQuest" 

But the viewfinder is not bad, has a coupled rangefinder and moving parallax mask.

The lens is an excellent single coated 4-element Schneider Xenar 45mm F2.8 and very Tessar like, with excellent contrast and very sharp at mid range apertures. There's also a very neat depth of field indicator over the distance scale. Pray to not have it jammed, because it's another freaky mechanism. 

Last word: Forget about Retina's built in meters. They are all horrible. Also avoid any autoexposure Retinas. It's very unlikely be working properly.

Lens: Schenider Kreuznach Xenar 45mm F2.8 (4 element)
Shutter: Synchro Compur with speeds from 1s to 1/500s