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Author Topic: Phase One XT: The First Modern Field Camera (and X-Shutter and new firmware)  (Read 3398 times)

Doug Peterson

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Re: Phase One XT: The First Modern Field Camera (and X-Shutter and new firmware)
« Reply #40 on: September 13, 2019, 10:26:05 am »

Some observations w.r.t. an XT design and an integrated focal plane shutter:
- flash sync: 1/125 => I can’t deny this, but how troublesome is this? Think about the huge amount of cameras with a sync speed of 1/125… 1/250. Can’t be that unusable. I’d also like to mention HSS.

The use case here is adding fill flash (or in some cases, key-light flash) to architectural interior shots when direct daylight is streaming through the window. In this use case every stop of flash sync speed means (pick any):
- Another stop worth of lighting ratio between your flash and the ambient light
- The option to bring either half the power packs / heads or power packs and heads that are one stop less powerful
- The ability to light a room 40% taller/larger than you otherwise would have been able to do, without changing the ratio of the ambient light

HSS is a great technology that opens up focal plane cameras to flash at higher speeds in specific situations (e.g. close up portraits you can shoot at 1/4000th flash sync and overwhelm the sun if you choose) but it reduces the effective power output of the flash considerably, and is rarely useful in the use case of architectural interiors.

Obviously, like any technical advantage, this may matter a great deal to a given user, or may not matter at all. That will depend on the photographers style and needs.

- vibration: considerable => I question this. In many cases with DSLRs mirror slap and shutter vibration are mixed up. Here we only have risk of shutter vibration.

Yes, some people mix those two up. However, either can be problematic.

FPS vibration is most problematic within a "bounce" range, typically around 1/8th of a second plus or minus 1-2 stops. It is, for example, very rarely problematic at 1/125th or at 2". You can search "shutter bounce" for more information on this topic. It is typically more problematic with a lighter tripod (such as the one you might expect someone to travel with when they buy an XT motivated by its small and light form factor). It's also typically more problematic with a long lens; there are no such native lenses for the XT yet, but of course there will be in the future, so that has to be accounted for in the body design.

Note that there are three reasons this is more of a problem in high-end medium format than in the broader market:
- the FPS we are talking about here are for full-frame 645 and so are about twice the area and more than twice the weight, so create more vibration
- the resolution (150mp) makes any given absolute amount of vibration/shake/bounce more visually apparent when reviewed at 100% pixel level
- the user base here is disproportionally obsessed with image quality

- flange distance: uses up several mm => no impact in case of fully integrating it in the camera design.

Imagine you now want to add some new accessory such as a lens adapter for other types of lenses or a tilt-swing adapter. In such cases every mm you have eaten up in fixed-cannot-remove body depth is a mm you can't use for that accessory. I would definitely acknowledge this as a lower impact than the other items listed, but it is a real impact none the less.

alifatemi

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Re: Phase One XT: The First Modern Field Camera (and X-Shutter and new firmware)
« Reply #41 on: September 14, 2019, 02:24:21 pm »

Is there a chance we see a comparison between photos taken by XT vs XF with approximately equal focal lens here? I like to see if there is any meaningful differences regarding quality of XT compared to XF, if anything at all.
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TechTalk

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Re: Phase One XT: The First Modern Field Camera (and X-Shutter and new firmware)
« Reply #42 on: September 16, 2019, 09:18:17 pm »

If P1 used their FPS (focal plane shutter) for the XT:
- flash sync: 1/125
- vibration: more than LS
- aperture control: manual
- lens metadata: none
- durability: ~100,000
- flange distance: uses up several mm

Because P1 used their X-Shutter (a leaf shutter) on the XT:
- flash sync: 1/1000
- vibration: negligible
- aperture control: automatic
- lens metadata: automatic
- durability: 1,000,000
- flange distance: no impact

Shutter type has absolutely nothing to do with manual or automatic aperture control. Shutter type has absolutely nothing to do with transfer of lens metadata.
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BernardLanguillier

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Re: Phase One XT: The First Modern Field Camera (and X-Shutter and new firmware)
« Reply #43 on: September 17, 2019, 06:55:56 am »

What is the longest lens that is planned to be supported on the XT?

Thank you.

Cheers,
Bernard

matted

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Re: Phase One XT: The First Modern Field Camera (and X-Shutter and new firmware)
« Reply #44 on: September 18, 2019, 06:26:10 am »

Shutter type has absolutely nothing to do with manual or automatic aperture control. Shutter type has absolutely nothing to do with transfer of lens metadata.

Agreed; Phase could have just as easily put their FPS inside the XT and developed an “X-aperture” for the lens that does everything the x-shutter does, minus the shutter part. Heck, they could have put an FPS inside the XT AND released the x-shutter as is and give the user the choice between leaf, FPS, and electronic shutter.

Obviously these options could result in higher R&D costs and/or costs to the end user and are not “just as easy”, however all could have been possible should they have been Phase’s design goal.
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Doug Peterson

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Re: Phase One XT: The First Modern Field Camera (and X-Shutter and new firmware)
« Reply #45 on: September 18, 2019, 09:35:52 am »

What is the longest lens that is planned to be supported on the XT?

There is no upper limit on the longest lens planned.

Natively integrated lenses (with fully electronic aperture/shutter/triggering control etc) will be rolled out based on user feedback. You can submit yours here: https://phaseonext.com/category/feedback/

Logical outcomes of such feedback would likely include native XT implementations of:
- Schneider 240LS BR, including the optional 2X TC
- Rodenstock 180HR

However, I make no promise on when, or in what order compared to other lenses as, again, that depends on user feedback.

TODAY you can use:
- The native XT lenses (23/32/70) which obviously does not including anything long (though in a pinch you could crop the central, say, 50 megapixels from the XT 70mm for a relatively long effective lens length)
- Any Cambo mount lens that does not include a rear extension, including the new Rodenstock 138HR
- Any Hassy 500 lenses
- Any Canon lenses, though many will not cover the full 645 frame of course and you'll want the DT Lens Panel Removal tool for Phase One XTl to remove the pane afterward (otherwise the XT makes accessing the release quite a chore).

Doug Peterson

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Re: Phase One XT: The First Modern Field Camera (and X-Shutter and new firmware)
« Reply #46 on: September 18, 2019, 09:54:44 am »

Shutter type has absolutely nothing to do with manual or automatic aperture control. Shutter type has absolutely nothing to do with transfer of lens metadata.

Agreed; Phase could have just as easily put their FPS inside the XT and developed an “X-aperture” for the lens that does everything the x-shutter does, minus the shutter part. Heck, they could have put an FPS inside the XT AND released the x-shutter as is and give the user the choice between leaf, FPS, and electronic shutter.

Obviously these options could result in higher R&D costs and/or costs to the end user and are not “just as easy”, however all could have been possible should they have been Phase’s design goal.

You are, of course, both right on the technical merits. However, from a practical perspective the two are very closely linked as far as product design / product management goes.

The core of the XT lens lineup is the Rodenstock HR series. Other lenses are possible today (Schenider digitar, Canon, Hassy 500) and others (Schneider LS BR? Hassy? Contax?) can be  added to the roadmap based on user feedback. But I expect the Rodenstock HR series will forever remain the core lenses used by most XT users. They are incredibly sharp, and they have image circles designed for 645 sensors + movement.

These lenses do not otherwise have electronic control. Since simplifying the tech camera workflow is a core design goal of the XT it's important to have electronic control and integration into the system; for example the ability for the back to control the aperture for live view, capture, and bracketing purposes, and for there to be metadata for the lens model and capture aperture for automatic lens corrections.

So the XT definitely needed something to provide electronic control of a Rodenstock HR lens. It ALSO needed some sort of shutter (as sensor-based ES is very useful in many situations, but is limited in terms of moving subjects and flash sync speed).

So how can we solve these two needs: Electronic Lens Control Need and Shutter Need?

One way to solve the Electronic Lens Control Need, the way that Phase One chose, is to put an electronic shutter+aperture unit in the lens (the X-Shutter) and design the body to pass the electronic connections of the lens to the back. This also solves the Shutter Need. Two birds with one stone.

If Phase One chose to pursue a Focal Plane Shutter (FPS) in the body this would have addressed the Shutter Need but, in and of itself, would not have done anything about the Electronic Lens Control Need. As you correctly point out the two are "unrelated" in an engineering sense so adding the FPS has no effect on the Electronic Lens Control Need. So if adding an FPS would mean you'd need a separate solution for the Electronic Lens Control need.

Now, as Matted points out, Phase One could have absolutely done both: a Focal Plane Shutter (FPS) in the XT body and an "X-Aperture" for each lens. However, the result would be a "worst of both" situation in many ways:
- The limited durability of an FPS. Maybe not a deal breaker for many users, especially shooting landscape. But it is, none the less, a clear advantage for an X-Shutter that it is expected (and tested) to last a million captures.
- The increased vibration of an FPS. Maybe not a deal breaker for many users since it only affects certain combinations of shutter speeds, lens length, and tripod/head combos.
- The decreased design flexibility imposed by the mandatory space taken up by the shutter. I can't say more about this since some of the ideas that might take up this space are not public.
- The decreased battery life due to the higher power required to run an FPS vs LS. Carrying an extra battery or two on a longer shoot/trip, of course, is not a big deal, but the XT is built as a Field Camera explicitly with travel-friendly form factor as a high priority, so it runs against its goals.
- The lower flash sync speed of a FPS vs the 1/1000th of the X-Shutter. Of zero importance if you don't use flash. Of varying importance those who use flash depending on when/how they use flash. For some: quite important.

In addition I don't expect an X-Aperture would be necessarily less expensive. An X-Aperture would still require mounting/calibration, an aperture, new housing, and new electronics. Moreover, much of the X-Shutter (including the firmware, software, and mechanical design and testing) comes from developments done in the Phase One Industrial/Aerial division, so didn't carry the full development cost of a new product. An X-Aperture would certainly share some of that, but anytime you make significant changes to a product there is considerable overhead of branching development into a new product (new firmware, new testing, new housings etc). So you likely wouldn't get any cost savings per lens. Notably, by adding the FPS you would get the 1/4000th max mechanical shutter speed which would be useful for fast moving subjects (the sensor-based ES of the IQ4 can do 1/4000th but will exhibit rolling shutter effect on fast moving subjects) and that could be of value to some shooters. You would also gain faster flash sync speed (1/125s instead of 0.3s) for 3rd party lenses that don't have a shutter, though I expect most XT users will be using lenses that do have shutters (e.g. XT lenses, LS BR lenses, Cambo lens panels with copal shutters).

Matted also suggests the possibility they could have done both: an X-Shutter in every lens and an FPS shutter in the XT body. The tinkerer inside of me actually likes this idea quite a bit. But the XT is clearly and unapologetically targeting weight, size, and simplicity as its highest priorities other than image quality. For this to really hit home I think you need to pick one up and use it. We have an article where we compare its weight and size to other cameras and it's pretty surprising. https://phaseonext.com/the-xt-is-smaller-and-lighter-than-you-think/. Having both shutters I think would clearly play against that goal and would make the system even more expensive. But I do like the idea from a "have it all" perspective!

In conclusion, there would absolutely be a few advantages to adding an FPS, but the disadvantages play against the core goals of the XT. How those balance for any given user is of course going to depend on their needs/wants/priorities. If the benefits of a Focal Plane Shutter are very important to the work you do then the XT is clearly not a good solution for you! That's okay! There are lots of good solutions out there that differently prioritize different pros and cons. From the clients I work and the conversations I've had in the last few days, I'd say the vast majority will not miss a FPS and will enjoy the benefits of the X-Shutter, but "vast majority" is not everyone!
« Last Edit: September 18, 2019, 10:20:57 am by Doug Peterson »
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Doug Peterson

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Re: Phase One XT: The First Modern Field Camera (and X-Shutter and new firmware)
« Reply #47 on: September 25, 2019, 04:40:28 pm »

Just a note that the DT LCD Shade for Phase One IQ is now on our eStore and starts shipping on Monday (Sep 30) and we have a limited number of units in our first batch, many of which are already spoken for. So if interested I'd jump on it now.

DT LCD Shade for Phase One IQ


« Last Edit: September 25, 2019, 09:06:12 pm by Doug Peterson »
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teamwiess

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Does anyone have any hands on experience yet?  Would love to hear perspectives on the XT as I am thinking of getting one.  Also what lenses have you been using?
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