What will the fujifilm medium format mirrorless camera be like?

Thanks, fujirumors, for sharing the rumour about an interchangable viewfinder for the hopefully upcoming Fujifilm mirrorless medium format. If true, this makes all the difference in the world for the camera and says so much more about what it is going to be like that i can almost give a shot at predicting it.

What the heck, ill give it a try.

(Its been released now, so how did i do? Find out at the bottom.

An interchangable viewfinder, what difference does it make?

When making an interchangeable viewfinder for an EVF camera one have two options. 

1. A detachable EVF.
2. A small sized amoled screen, much like an SLR focusing screen. Lets call it the EFS, electronic focusing screen.

Nr 1 has been used with quite low success but several mirrorless camera manufacturers. All the solutions were technology driven, expensive for the photographer and commercially rather unsuccessfull.

Nr 2 is an modern version of common solution from SLR world, but untried in a mirrorless camera. It is a lot cheaper, especially for a waist level finder that is nothing more than a foldable shade with a likewise foldable looking glass. For the eye-level viewfinder, prisms cost a bit more, but sometimes a cheap mirror may do the trick almost as good. If the EFS thingy is up-flippable within the eye-level finder it may in fact obsolete the prism all together.

With Fujifilm, a release of a new system always seems to come with a twist. Something novelle or quirky, sometimes brilliant, sometimes more or less pointless. I think its because most Fujifilm product lines start with an idea of how to improve or revive a certain aspect of photography with a new solution. It could be another new kind sensor pattern, moster tilt-shift medium formats, 6x8 frame size to fit magazine covers perfectly, reinventing instant photography, very short 120-films to suit drop-in studios, film simulations, yet another sensor pattern or another one again. Nothing has been predicted in the MMF rumours we have heard up until now.

I'd say Nr 2 would make this camera fit right into what to expect from a new Fujifilm product line. At the same time it makes the whole rumour of a MMF a lot more beleavable. It would also be the cheaper way to go and being cheaper than Hasselblad is kind of important here. 

The implications

With a focusing EVF on top of the camera, it will not look like the Hasselblad, the x-t1 or an x-pro2. It will look more like a SLR or a classic MF camera (of which there are many different designs, a bit more on that later).  Whatever they choose, the camera will be deeper than the Hasselblad that is a very thin camera being a medium format. That means that they can fit a focul plane shutter where the mirror would have gone in an SLR, without making it bulky. I know, Fuji do like their leaf shutters, but large leaf shutters are expensive and if you want to make them really fast, they are really expensive. They also make the lenses heavier. Another implication of a deeper camera is that the lenses can be shorter, since the sensor can be a bit further back and some of the focal length can be kept in the camera. I would love a telescopic tube or a TLR-like movable front behind the mount to keep the lenses down to large format size and even allow crude AF with adapted lenses, but i think the R&D and production cost of that would be a bit on the high side unless they come up with a super brilliant solution. I would rather expect a fixed register, something in the range of a regular small frame (D)SLR. Short enough to adapt most medium format lenses, but long enough to keep 44x33 covering optics rather small.

Interchangable viewfinders also limits where you can put the hot shoe and a pop-up the flash. We will most certainly not see a pop-up and the hot shoe may either be left out too, pushed to the left of the viewfinder or put in an unconventional place. Far left is is my guess.

Other conclutions

Sensor

Well, there is only one that would meet the requirements of being not to expensive and good enough. The Sony 50Mp 44x33mm one. Bayer or xtrans then? Rumours sais bayer and so does logic. Fuji will want to go with a perfect colour alternative here. Binning the 50Mp bayer would give true RGB on every pixel on 12,5Mp and a smart demosaicing algorithm would give twice the size with almost perfect RGB and almost 50Mp shapes. Then there is the problem with the current cost of a computer (and internal circuitry) that can demosaic an 50Mp xtrans file in bearable time. There is also the fact that a bayer sensor may still scare off less potential customers than an xtrans.
Bayer it is!

Interface

Fuji allready has a well tested interface of dials, knobs and buttons on the x system. I dont expect them to put resources into another one. We will propobly see the film simulations and most of the menu system duplicated as well. Then there is the question of the screen. If the camera is sold with the WLF as standard, its not impossible that they may skip the big screen in the back. However, i think the first release will be the premium model, a cheaper single screen may come later.

Touchscreen? Not yet, first they need to evaluate that on the cheaper x cameras.

Form factor

SLR-like, TLR-like, HB-like, P-67-like or even GA645-like? Well, i think they will keep the system specs so that they can build most of these in the future. However, for the first model i think its going to look a bit like the Reflex Beauty, but with a grip for the right hand. A small box to house the shutter inside and the EFS on top with a mount for the lens in front and another for the viefinder on the top. The box will most likely be a bit smaller since the 44x33 is smaller than the 55x55 of the beauty reflex. Maybe they will keep the electronic focusing screen at the modern standard 645 size of 56x42mm or their own 645 that is more like 55x43.5mm. Behind the box there would be a fixed back, with electronics, battery and memory card slots, with knobs, dials and buttons much like an x-pro2 or x-t2 and the same screen as them on the back.  All and all like if one would take an x-pro2 and put a small box in front of it and the viewfinder mount on top.

Ofcourse there will be cheaper models if the first one sells well enough. An HB 500c form factor or even a TLR-like camera, but with only one lens at the entry level are viable options in the future.

IBIS

The only reason why Fuji would implement IBIS would be that they were planning to go for a 645 sensor in a future genration so that the lenses were allready 645 prepared. That would actually make some sense here. But the do allready have in-house tech for OS lenses and IBIS is harder to implement the larger the sensor is. So its definetly a no anyway.

Lenses
Three lenses are rumoured to be first released. One normal and one portrait tele plus a wide to normal zoom.

Summary of my prediction compared to the real deal.

• Reflex Beauty style camera
  Not to bad. I didnt see the brilliant move of moving the grip of the camera forward to make it more balanced. But the box is there, just as predicted but its just visible on the back instead of the front.
  
• X system like handling and output
  Was pretty obvious.
  
• 50Mp 44x33 bayer sensor with True RGB binning option
  This is not clear as of yet. We still think bayer and they presented a few tricks of downsizing. More info on this later.
  
• Invention of the EFS, the electronic focusing screen
  Fail! It may still come on a future model.
  
• Small lenses compared to the ones of Hasselblad
  They are smaller, but not super small.
  
• Sadly no bellows, tube or other retractable mount
  Right, sadly enough!
  
• A bit thicker a body compared to the Hasselblad one, but smaller with most comparable lenses mounted
  Spot on!
  
• First body only slightly cheaper than Hasselblads, cheaper ones coming later
  First part is right at least, time will show if the second part is right.
  
• Neither touch nor flippable screen
  Half fail, with no WLF, the flippable screen has to be there. They didnt say anything about touch though.
  
• A focal plane shutter is slightly more likely than leaf shutters
  Right
  
• No IBIS
  Right
  
• Pop-up flash, no
  Right
  
• Hot shoe, far left on top of the camera
  Wrong, sort of. They have an odd hotshoe solution, but its on top of the viewfinder on the regular one. But with the angle finder, where is it then, is there none at all?
  
• Three lenses: Wide-normal zoom, normal and portrait tele primes.
  Kind of wrong. I don't think anyone see them anounce a six lens system.
  
• Weather resistant
  Right.

Oh, im gonna be so wrong...
Well, it could have been a lot worse. What was really wrong was the viewfinder construction and thus also the touchscreen. I'm pretty impressed with what i have seen of the system so far and hope for more (hopefully) cheaper bodies to be released in the future.

Thanks Fujifilm, for releasing such an impressive system!

Purple flares and grid pattern on xtrans: Why its there and how to remove it

There have been a few discussions and posts over the years about a phonomenon on some digital cameras where a grid pattern is appearent in purple flares when pixel peeping. Here is a discussion on the topic from a few years back, that time about a Sony camera.
Now it has become appearant that the effect can occure in xtrans sensors as well. A few months ago Mathieu att Mirrorlessons wrote an article on it. I first read about it on a discussion a few days ago and have been doing some digging since, here is what i know and what have been able to find out the last couple of days.

Purple flare effect in general

Purple flare origins when there are strong light sources in line of sight of the front lens. The source can be, but doesnt have to be, in the frame to cause a flare. If its outside the frame, a well made shade usually helps on a prime. On a zoom lens the shade has to be made to protect only the widest end and if one zooms in, a light source outside the frame can still be in line of sight from the front lens. Filters and dirty front lenses will usually increase the effect.

Flares can usually be avoided, but sometimes they look really good and thats when the real problem occure. If you want it there it has to be well rendered in your photo.

Film vs digital

On film this is usually not a problem unless you scan the negative. If one makes an RA4 copy, a well placed purple flare looks awesome. On a digital camera or a scanned image, things get more complicated. Purple flares over highlights usually work ok, but on shadows, and gray to black highlights in particular, they often become problem. On every camera i have been using (doesnt include sigmas) and every scanner i have used (which are a lot) what always happen is that the post processing latitude turns to almost zero if such a flare is present. Any pushing, pulling, sharpening or even white balance shift will make it look horribly ugly if you dont treat it carefully. Further more, if shot with a digital camera, usually the tolerance for cropping decreases a lot too. To much cropping and one of several kinds of artifacts are bound to appear. It can, for example, be clotting, loss of contrast or that part of the image just gets a different look. On xtrans files is it the grid pattern.

Why?

Mixing bright colour with dark gray is obviously not easy. Try to imagine it yourself. However, when its done right it can look very pleasant. I like to do in postprocessing my darkroom prints. On most papers it doesnt work at all. When it works, its because the papers have a structure like tiny hills and valleys. The black silver then only forms its shade of gray of the photo on the mountain tops in the highlights. Then i can rub colour down in the valleys without desturbing how much silver that should be visible. Even with such a paper it only works in the highlight areas of the photo, in shadow areas the silver reaches down in the shadows and there can be no mix. Digital images face very much the same kind of problems, a single pixel cant be both bright purple and dark grey at the same time. To create something that looks like that, some pixels have to have one property and others the other one. With some clever maths and enough pixels, this is fixable if you start with a picture that have all the colour information for every pixel. But ouch, a digital sensor doesn't have that. Every pixel only have one colour, and its green in 50% of the time on a bayer sensor and even more on an xtrans one. To a green pixel, purple looks almost black. So the amount of pixels the clever maths have to work with is seriously reduced in a purple flare.

The grid pattern

Why does xtrans form a grid pattern? To answer that we have to take a look at the xtrans pattern, so here it is.

As you can see, every fifth green pixel have a different coloured pixel on its side and a green one at its corners. However, four out of five green pixels only have differently coloured pixels at two of the sides. Demosaicing is complecated stuff and ill give you a very very simplyfied version on how it works from one of the green pixels perspective when being faced with purple light.

First it looks to its own information and sees black. Then it asks its longside neighbours. Half of them say black, one says slightly red, and one slightly blue. Including itself, a 3 to 2 majority vote black. Then it asks its corner neighbours and gets the same answer, 3 to 2 for black. The 5th green pixel gets another ansew from its longside neighbours, 4 to 1 majority says its not black which changes its mind.

Now lets look closely at an affected picture converted with lightroom and compare to the xtrans pattern. 

The result is the complete opposite of the prediction, but the pattern remains as the algorithm seems to overcompensate when there is not enough data. I have now looked at the output from several different raw converters including the in-camera one. Every single one creates this reverse pattern in the purple flares. Clearly some tweaking of the demosaicing algorithm in affected areas would be in order. It would still need the mix of brighter and darker pixels to keep the luster, but they have to be scrambled somehow.

Is this a problem worth bothering about?

Yes and no. It only shows this clear when pixel peeping and the kind of screen you use also affects how visible it is. However, when trying to post process a photo with a purple flare by any means to achive sharpening, cropping, clarity, opening up the shadows or changing the contrast, it is always the flare areas that sets the limit of how much one can do. If i was at charge at Fuji, i would dedicate some resources to investigate it and if i was in charge at Silkapix id definetly see it as a chance to show the world i was still ahead of Adobe.

Does it affect my pictures as a photographer? Almost never, and when it does, i know how to fix it in post for almost every case.

The post production solution

Lets start with a picture. This is from the x-pro2 with a 10-24 with a street lamp slightly in front of me, shining down on the camera from above . It wasnt in the frame, but the shade didnt cover my lens enough to keep the light from reaching my front lens. 

Here is a 1:1 crop, it dosnt look pretty at all:
(it uses the adobe standard profile with no modifications but slight clarity and slight dehaze to exagurate the effect)



From lightroom i then right click on the image and chose "Open as smart object in Photoshop". In fotoshop i select the whole image and apply box blur with the minimum strenght of 1, (I use gaussian blur 2 if the pattern appears as diagonal rather than horisontal/vertical). I then close photoshop and click save.

Here is the result that then automatically opens up i Photoshop as a PSD file next to the RAF:

The grid is gone and the loss of detail is much like using a sensor with aa-filter.

Here you can download the before and after pictures side by side. It is a crop at approximatly 1/4 of an xtrans III file.

Happy shooting with purple flares again!

P.S.
In Mathieus article there are pictures with a diagonal pattern as well. I have not been able to recreate that pattern. Could someone, please, mail me (roos@swedish.photography) a RAF of such a photo so that i can investigate it further?

More facts about film sizes

You should know that in photography, 6x6 doesnt equal 6x6cm image area, neither is 645 the same as 6x4,5cm nor is 4x5" 4x5", it would just have been too easy. Except for 135 film (small frame) the sizes include the borders of the roll film, making a 6x6 lens have to produce a circle of good quality that can fit a square of around 55x55mm. It varies a lot though. For example, im pretty sure my 6x6 P6 produces a smaller picture area than my 645 fujis do and my 6x12 produces only around 10cm wide a picture.

For large format it gets even more complicated. First we have to take into account that the nominal sizes are those of the film holders rather than the film itself. The film sheet has to be i bit smaller to fit the holder. By chance, this makes the slightly larger 13x18cm format have exactly 5" wide sheets, while film called 5x7" is slightly narrower than 5". In addition to this, there are the borders. For 4x5" format in total that means the image area is about 95x120mm which is between 0.5 to 1 cm smaller in each direction than the name suggests.

Does this affect digital as well? In a way, it does. Making a 60x45mm or a 60x60mm mf back wouldnt make anyone happy except the lens manufacturers. A lot of lenses for regular 6x6 or 645 systems would be quite useless with such a back since the corner would lose light, image qualitey or both. However, on digital backs and cameras, if you look carefully you will find the actual size mentioned. Just remember that while 44x33 is a 645 crop, around 55x55 is a perfectly sized 6x6 sensor.

On top of that, there are so many misconceptions on how film/sensor size affects the photos floating around the internet. I tried to straighten them out during a rainy day this winter.

http://bit.ly/2bFPmKO

I should try to make a shorter and better version of this, i know. But it at least tells how it sorts the myths out from the facts if you can get yourself through it.

Thats all for today, or tonights darkroom class will be a teacher short.

Entry level mirrorless medium format camera

Early summer, i put down my mirrorless medium format wishlist. Reading about the rumoured lenses on fujirumors made me realize a MMF done right could have so much potential. Here is how Fujifilm could make an affordable entry level that would still be attractive in low end medium format price ranges. (Edited the text after fixing some seriously flawed arithmetics)

The only certain known about the hopefully upcoming fuji MMF is the sensor. It will be the Sony 44x33 or not at all in the close future, whether modified to xtrans or not. This gives us a 4x3 aspect ratio which is quite close to optimal for fitting a lot of sensor area in an image circle so the lenses will not have to be too big. Its also gives the images the same proportions as the classic 6x45 film format, making it very suitable for waist level shooting.

Even an entry level MMF camera wouldn't come cheap so it would have to come with something very appealing, much like the x100 attracted a lot of attention and buyers without being the best performer at its going price. It would also have to strip away a lot of the extra stuff we would expect from an expensive Fujifilm camera.

One obvious thing we can expect to lose on an entry level camera is both the EVF and optical viewfinders. Other things that may have to go are big buffers, extra jacks for headphones and mics, dual sd-slots, weather sealing and so on. So would anyone buy a £2000-3000 x-m1 with those things missing?

I wouldn’t and i guess you wouldn't either. But what if i offered you this, but with the sony 44x33 instead of 127 (40x40mm) film?

A rather small (and thus cheap) screen as a wlf with a foldable cover and there you are, a small and retro MMF camera in TLR style but with only one lens, interchangeable or not. Maybe the screen could even flip back so that we can use it like a regular non-evf mirrorless camera when we want to look stupid instead of super trendy.

The X-T2 - the end of an era

Until now, the x series has been all about photography. We have all felt it, the cameras walk, talk and look like cameras. The knobs are in the right places, the needs of photographers have been dictating the firmware updates and development of new models.

With x-t2, the heat produced by 4k dictates the internal airflow design of the camera, some of the precious firmware development resources will be put on video features and bug fixes, not to mention the extra buffer memory that could have been there if all those video modes were not there. If it sells well among videographers, designers of future models will consult both photographers and video shooters regarding ergonomics, button layout and lens needs.

Ofcourse more sales at least in theory will come with more resources to r&d which hopefully can negate some of the drawbacks. But there is no question about it, from time to time there will be choices between what is best for photographers and what is best for videographers and from now on fuji will have to consider both groups. Thats why video cameras and camcorders dont look like still cameras and why spoons dont look like forks.

Let's hope we don't end up with a spork like those sonys and panasonics out there!

The MMF (mirrorless medium format) wishlist

Tomorrow, Hasselblad will announce their MMF. It's going to be fancy and expensive for sure and hopefully good and even groundbreaking. Given the history of cooperation between HB and Fujifilm with the H series, xpan and Fuji manufacturing HB lenses, there is a good chance Fuji is involved somehow. But let's leave exactly how and how much to when we know more and dream away a bit of what a Fujifilm MMF could offer!

Here is my wishlist in short (details follows):

1. 33x44
2. Price
3. X system look, feel and handling
4. EVF
5. Small size and low weight
6. Good lenses
7. DR and low light performance
8. Protect the sensor
9. Filming

33x44

There is only one sensor that makes sense for a Fuji MMF today. The sony 50Mp, roughly twice the size of a regular small frame (FF DSLR) picture frame. Anything larger would be too expensive and make the camera bigger. It's uses more or less the same tech as the x-trans II sensor, only it's about four times bigger. I will simply not wish for anything better, because i wouldn't want to pay the price for it. If Sony has improved it by making a second generation that gives the same or better performance at a lower price, i am all for it, of course.

Price

It has to be lower than the Hasselblad MMF, but it will most certainly be more expensive than a A7R2. Lets wish for closer to the Sony than the HB.

Look, feel and handling

Fuji has done very well with the x system in this regard. Lets hope they don't spend any money on doing it in a new way. An x-pro2 like body back and top with a better iso-dial would do great. They may go for x-t2 like, but losing the street and action photography advantage of seeing things moving into the frame that you get with the HVF would really be a petty on a small MMF.

The front will have to be different with bigger mount and i hope they will add a bigger grip to cope with more of the weight in the front.

They may even start with a fixed lens version or a step zoom like their 645z and go for interchangeable mount later. I think we will get a hint about that with the HB release tomorrow.

Bringing in the film simulations are crucial, lots of photographers are so happy with the jpegs that they only use the raws in special cases and Fuji will need them to tag along to MMF to get the volume up.

EVF

They could make an optical viewfinder only camera like the ga645 ones, but i really hope we will have a hybrid viewfinder. It has to be competitive, but not market leading in size and refresh rate.

Small size and low weight

This is arguably the very key to the product, thus i will elaborate quite a bit more on this subject.

How small can a MF be?

Well, have a look at the Voigtländer Bessa RF. It fits in a large pocket and it has 6x9cm picture frame.

That's about four times larger than 33x44!!!

How can that be?

Well, it's all about extendable flange. If you put a lens (or even a very small hole) 65mm away from the film or sensor, it will have the focal length of 65mm, hence the name. The amount of glass you need is minimal and you focus closer than infinity by moving the lens further away. However, if one want to keep the same flange and use a longer lens, you either need more and heavier glass or you have to put a longer barrel on the lens between the camera mount and the lens package. Let’s compare a regular 85mm DSLR lens with a 210mm large format lens (about the same angle of view on 4x5” as the 85 on the 24x36mm). The large format lens is very small and covers an image circle that is several magnitudes bigger than the DSLR lens. The drawback is that it has to be placed 8-9” away from the film.

When you make a fixed flange camera, like a DSLR or Fuji X or the Sony A7 you can make use of this when making a lens that has the same focal length of the flange of the camera. Just like Sony did with the 20/2.8 that more or less gave it it’s reputation of being a small and lightweight system. The price with such a short flange is that there has to be a tube on every lens making longer lenses big and bulky. If you, once again like Sony, add IBIS to the equation, making the sensors effectively bigger by moving it around, your long tube problem piles up on a wide problem and lens size goes from small to big to huge.

So how to solve it? Fuji already did on the ga645 cameras. On them a retractable tube can be telescoped into the camera when not in use. Bellows works just as well and are cheaper but comes with durability issues.

On the Fujifilm MMF i wish for a retractable tube with a lens mount in the front. This would provide all the following.

• Small and light lenses regardless of focal length. Fast lenses will ofcourse be bigger than slow, but that's just as it is.
• Design choices on auto focus. The lenses can have internal motors for fast focusing or money and weight can be saved by using the slow but accurate focusing method of moving the tube.
• The camera would be very flat with the tube retracted.
• Almost any lens that covers 33x44 could be mounted and used with slow but accurate AF.

In the end i wish for the camera plus a few lenses to fit in the same bag that holds an Canikon DSLR or a Sony A7 with equivalent lenses. If the camera with a small lens could fit in one of the large pockets of my jacket i would pay $500 more.

Good lenses

Fuji knows how to make good small frame lenses, good medium format lenses and good large format lenses. If they make the effort, they will make good 33x44 lenses. I just wish they will focus on that rather than dirt cheap or lots of lens options early on. If they build the camera smart, there will be enough options by adapting lenses while they expand the system slowly.

DR and low light performance

We know what we get with this Sony sensor, it performs well and Fuji will tweak it a little further. Two stops better than aps-c is the mark to reach for, but 1.5 is good enough.

Protect the sensor

Please Fuji! There should be a shutter-like thingy that covers the sensor when the lens release button is pressed and opens when next lens clicks into place. Why don’t we have this already?

Filming

Any minute on spending R&D time and resources on filming features are wasted on me. But if it pays itself by reaching a larger audience i'm all for as long as they don’t dedicate any buttons or knobs for filming and that fiming settings don’t get in the way of finding useful menu entries and alike.

Pure speculations: The G4433 - the digital exchangable lens folder

Do you remember this?

That is the GS645, Fuji's pocketable 6x4.5cm rangefinder from the mid 80s. Folding rangefinders are usually single lens cameras. The lenses are usually neither tele nor wide angle designs, but sits at the same distance from the film as their focal length. That way the lenses can be kept very small even if they are of the best possible quality, much like large format lenses. Up until now, digital folders and interchangeable folders have been scarce. It is very hard to create a rangefinder system that is reliable with different lenses. Every lens needs its own cam and they also need different infinity stops.

However, now we have EVF and phase detection pixels on digital sensors. We neither need a proper rangefinder nor a big mirror flapping around to focus. The implications are very interesting. One now could build a folder with swappable lenses or even with an extending telescopic tube like on pocket cameras or the ga645 cameras, only with a mount at the end where one could attach very light and small lenses. And we still could focus them just as well as with an x-t1 or x-e2.

The current rumours says Fujis next camera system will be a digital one with a large 50Mp sensor. That fits perfectly with the excellent dwarfed medium format sensor of the Pentax 645Z. (Dont worry, with its 44x33mm it's still almost twice the size of a full small frame sensor.  Put an xtrans filter on it and put it in a ga- or gs645 package and it will be an excellent sony a7 killer.

Ofcourse I could be totally wrong or the Fuji MF rumour could be nothing but a rumour, but a G4433 fits the specs well and it would be very very Fujiesque.