Phase XF with IQ3 100 tips request

[tashley]

Good morning.

My XF/3-100 has arrived and I'm cracking on with using it both as a kit and with the back separately on an Alpa STC.

Having only last month taken delivery of my X1D, it's an exciting and interesting time. However, the Phase kit, purely as a result of its exceptionally deep and rich feature set, is the closest to overwhelming that I've ever come across. I've owned and used quite a lot of MFD gear so I know the territory but wow, is there a lot to learn.

My 'known unknowns' mainly relate to ISO and DR. With the IQ180 you really had to shoot at ISO 35 to get the best from the back. With the the 3-100 I have started similarly by shooting at 50 but I'd really appreciate input from those with experience of the system as to whether this is really necessary? For example, well before dusk yesterday I was shooting the back on the STC and using the full electronic shutter. I kept on running into shutter speeds that required a dark frame which means you have to put on the lens cap.

This felt fiddly, and I thought I would generally revert to the leaf shutter on my Rodie in future. However, were I to bump up ISO to 100 or even, gasp, 200, how much DR would I lose?

In other words I have no idea what the base ISO of the sensor is. Is 50 truly base or is it a pull? Is the sensor ISO invariant? Do I lose DR as I move to low-middle ISO? I can't seem to find much information on this.

My 'unknown unknowns' are just that: I have no idea what I don't know but might be useful. I've read a few reviews but the gnarly and wise folk on here will no doubt know all the down and dirty stuff that I would take months to work out on my own - such as how to deal with the issue of setting latency as you shuffle between technical camera use and use on the XF!

All donations of knowledge gratefully received, and thanks in advance!

 

[voidshatter]

This felt fiddly, and I thought I would generally revert to the leaf shutter on my Rodie in future. However, were I to bump up ISO to 100 or even, gasp, 200, how much DR would I lose?

In other words I have no idea what the base ISO of the sensor is. Is 50 truly base or is it a pull? Is the sensor ISO invariant? Do I lose DR as I move to low-middle ISO? I can't seem to find much information on this.

Congratulations and welcome to the CMOS era! :grin: I'm sure you'll enjoy the Live View, DR, high ISO performance, tiling-free image quality etc!

Base ISO for IQ3100 is ISO100. ISO50 is a pull of ISO100. Evidence: link (Note that base ISO for IQ180 is also ISO100, while ISO35 is just a pull. Evidence: link)

For anything above ISO100 with the IQ3100, you lose 1 stop of DR per stop of ISO increase (link).

To fully utilize the DR, you expose to the right without overexposing much highlight (at ISO50 or ISO100). You'll need to get familiar with the property of the back and verify with RawDigger whether you can trust the in-camera histogram and highlight warning. For example, if you pick ISO50 then stick with it every time you shoot on a tripod, and get familiar with the histogram of ISO50 (check with RawDigger how much overhead there is, so you know how to ETTR without blowing out much highlight details).

 

[dchew]

Tim,
I can't add anything to the ISO question, but I do use ES all the time and I don't put the lens cap on, I just close the leaf shutter to take the dark frame. Never had any poor dark frame/light leak issues that I can tell.

It still does feel fiddly to me. Wayne points out if you get in the habit of pressing the shutter button while on the live view screen, you won't ever make the mistake of taking a black shot with the shutter closed because of the previous dark frame. I have a lot of those images. :facesmack:

I do think once you get in the habit of using ES you will fall in love with it. Can't remember the last time I pulled out the cable release and sync cables.

I went so far as to remove Alpa's shutter lock, thinking that would make it a bit smoother. But, after 6 years with the camera it felt weird without that quirky little lever so I put it back on.

Dave

 

[voidshatter]

I went so far as to remove Alpa's shutter lock, thinking that would make it a bit smoother. But, after 6 years with the camera it felt weird without that quirky little lever so I put it back on.

Dave

I think the new golden ring Alpa lenses have no shutter lock? I tested a sample of golden ring from Linhof Studio, which did not have the shutter lock, but from Alpa's website I can see the shutter lock there. I'm also told that the non-golden ring Alpa lenses have depreciated for second-hand value, because a Chinese workshop is producing lots of knock-off Alpa lenses with raw lenses, so that customers in the second-hand market are wary :facesmack: Actually they can replace pink ring and blue ring with golden ring easily...

 

[vjbelle]

There are numerous settings for Dark Frame on the 3100 and the one I use requires a single dark frame and after that no dark frame. To access this setting the camera is in 'Normal' mode and the dark frame icon on the back is turned off (by pressing and a X should show). With this setting the only times the back would require a new dark frame is for a wide exposure difference from the first dark frame or if there is an iso change. I also use a 2 second delay just for safety. If I need to fire the shutter instantly I use my iPhone 7 plus and capture pilot which is very handy but WIFI activated on the 3100 is an additional drain on the battery which is noticeable.

I shoot at iso 100 almost exclusively unless conditions are such (wind) that I need more speed. I have had extremely good results up to 800 which is more than I would ever need.

I don't have an XF (no need) so no help there.

I have toyed with either of the two new mirrorless offerings but still can't find a need. If the camera goes on a tripod then it will be my Actus. If its hand held (which is 1/10 of 1% of my shooting) then it may as well be my iPhone. Only speaking for myself.....

I don't think you will ever regret your purchase of the 3100.

Victor

 

[Paul2660]

Victor's comments are right on.

On the tech camera, once you hit the x for no dark frame unless you make a large change in the shutter speed, the back will no longer continue to fire one. I SURE WISH THIS WAS AVAILABLE ON THE XF. Should not be that big a deal, but for now, you can't turn off the dark frame at all with the XF (unless this was added with the latest firmware) My XF has been in for a few repairs lately.

ISO, opinions vary here, mine are that again up to 800 the back will perform very well, but even at ISO 800 I don't expect much push. Past 800, 1600 and 3200, results can be very good, if you expose for the frame and don't plan to push, but still the results could be better. IMO P1 doesn't get the best from high ISO on their backs, just doesn't seem to be a point of dedicated design.

I use 50 and 100 the most and you can expect as much as 2.7 to 3 stops of push with either when needed.

Paul Caldwell

 

[algrove]

Congrats Tim. Nothing more to add, but I always thought native ISO was 50. Learn something everyday.

 

[dougpeterson]

Victor's comments are right on.

On the tech camera, once you hit the x for no dark frame unless you make a large change in the shutter speed, the back will no longer continue to fire one. I SURE WISH THIS WAS AVAILABLE ON THE XF. Should not be that big a deal, but for now, you can't turn off the dark frame at all with the XF (unless this was added with the latest firmware

Paul, this is available when using the DT Time Lapse Suite. 100% control of the dark frame, including the ability to absolutely disable it, even when making large changes in shutter speed. The app also provide a read out of the current sensor temperature and the temperature at the time of the last dark frame, so that you can make an informed decision whether a new dark frame is called for (which you can then request on demand from the app).

 

[dougpeterson]

Re: native ISO of the IQ3 100mp: Assuming the question is a more sophisticated way of asking "what ISO should I shoot at if I want to get the best image quality?" then my answer is unquestionably ISO 50. The availability of the clipping warning on the IQ3 (different and more useful than the "exposure warning" that is found on the IQ3100 as red blinkies, as well as on nearly any other camera) means you can easily, and with absolute confidence, check that you are exposing in such a way that you're coming close to, but not actually clipping (i.e. lots of exposure warning but little to no clipping warning, at least in any subject matter you care to retain any detail in) the raw data in a way that is not elegantly recoverable.

Therefore for nearly all photographers and use cases shooting the IQ3 100mp at ISO50 and using either the normal histogram or the new clipping warning tool shooting at ISO50 will lead to consistently better image quality.

Any explanation more technical than this is just a pissing contest about technical inner workings of the sensor, the definition of ISO (and rampant divergence from this specification by a variety of manufacturers), and the ramifications of 1-channel recovery in modern bayer raw processing. I can hold my own in such a pissing contest but can attest that it has little practical value.

Note: looking at the browser render the JPG render and forum resize don't handle his face very well; that looks better in the TIFF on screen. I should probably have reprocessed it at forum size, but you get the point.

Summary
Put it at ISO50 and don't blow any highlights that you care about.

Other ISOs
As a side note, of course the IQ3 100mp will also produce very good results at higher ISO. If you're not making a huge print then some truly crazy ISOs should not be ignored. Here is an ISO 32,000 equivalent image from an IQ3 100mp (ISO12,800 marked on camera, with a ~1.5 stop push in post):

Most of the grain in this image is added in Capture One using the Film Grain tool. This image would NOT make a stellar 5 foot print (the noise/detail/tonal-smoothness/blotchiness when viewed at 100% or other large-print-size equivalent magnifications is pretty rough - it is ISO 32,000 after all) but it easily handled what I'd normally use a dSLR for in the past – quick shots that only need web resolution (this project was processed at 2000px wide) but which require high ISO.

 

[voidshatter]

Any explanation more technical than this is just a pissing contest about technical inner workings of the sensor, the definition of ISO (and rampant divergence from this specification by a variety of manufacturers), and the ramifications of 1-channel recovery in modern bayer raw processing. I can hold my own in such a pissing contest but can attest that it has little practical value.

There is practical value of marketing. If you admit that the Nikon D810 can shoot at ISO32, then where's the so-called advantage of medium format IOS35 and ISO50?

 

[Paul2660]

Paul, this is available when using the DT Time Lapse Suite. 100% control of the dark frame, including the ability to absolutely disable it, even when making large changes in shutter speed. The app also provide a read out of the current sensor temperature and the temperature at the time of the last dark frame, so that you can make an informed decision whether a new dark frame is called for (which you can then request on demand from the app).

Hi Doug,

I looked up the suite on the DT site, is there anywhere to download a users manual?

Also, do you have to be tethered the entire time? Not a huge issue just curious.

For star work, this is a great tool for sure. Here I would be using a set series of exposures say 2" each, so the app would for sure kill the normal dark frame. But on the XF I thought this was possible anyway as long as you are in Time lapse mode?

But would it help in this situation? I want to shoot a 1", 2", 5" and 10" series of exposures all on the XF and 100. Normally even on the tech camera as I understand it with this great a range of exposures, I still be asked to shoot a shot with a lens cap on at least on the 5" and 10". But with the app from DT, can you defeat the Dark frame altogether, and thus shoot the 4 exposures without any dark frame? That would be worth the price of the app for my workflow.

Thanks in advance.

Paul Caldwell

 

[dougpeterson]

I looked up the suite on the DT site, is there anywhere to download a users manual?

No. But the feature set is straight forward enough that we can gladly answer any questions as they arise.

Also, do you have to be tethered the entire time? Not a huge issue just curious.

Yes.

For star work, this is a great tool for sure. Here I would be using a set series of exposures say 2" each, so the app would for sure kill the normal dark frame. But on the XF I thought this was possible anyway as long as you are in Time lapse mode?

In this case the XF Time Lapse Tool will suffice.

If, for example, you do the same thing on a tech camera rather than the XF then the DT Time Lapse Suite would be needed.

But would it help in this situation? I want to shoot a 1", 2", 5" and 10" series of exposures all on the XF and 100. Normally even on the tech camera as I understand it with this great a range of exposures, I still be asked to shoot a shot with a lens cap on at least on the 5" and 10". But with the app from DT, can you defeat the Dark frame altogether, and thus shoot the 4 exposures without any dark frame?

Yes.

 

[tashley]

Paul, this is available when using the DT Time Lapse Suite. 100% control of the dark frame, including the ability to absolutely disable it, even when making large changes in shutter speed. The app also provide a read out of the current sensor temperature and the temperature at the time of the last dark frame, so that you can make an informed decision whether a new dark frame is called for (which you can then request on demand from the app).

Us poor Brits - we can't buy from you guys!

 

[tashley]

Re: native ISO of the IQ3 100mp: Assuming the question is a more sophisticated way of asking "what ISO should I shoot at if I want to get the best image quality?" then my answer is unquestionably ISO 50. The availability of the clipping warning on the IQ3 (different and more useful than the "exposure warning" that is found on the IQ3100 as red blinkies, as well as on nearly any other camera) means you can easily, and with absolute confidence, check that you are exposing in such a way that you're coming close to, but not actually clipping (i.e. lots of exposure warning but little to no clipping warning, at least in any subject matter you care to retain any detail in) the raw data in a way that is not elegantly recoverable.

Therefore for nearly all photographers and use cases shooting the IQ3 100mp at ISO50 and using either the normal histogram or the new clipping warning tool shooting at ISO50 will lead to consistently better image quality.

Any explanation more technical than this is just a pissing contest about technical inner workings of the sensor, the definition of ISO (and rampant divergence from this specification by a variety of manufacturers), and the ramifications of 1-channel recovery in modern bayer raw processing. I can hold my own in such a pissing contest but can attest that it has little practical value.

Note: looking at the browser render the JPG render and forum resize don't handle his face very well; that looks better in the TIFF on screen. I should probably have reprocessed it at forum size, but you get the point.

Summary
Put it at ISO50 and don't blow any highlights that you care about.

Other ISOs
As a side note, of course the IQ3 100mp will also produce very good results at higher ISO. If you're not making a huge print then some truly crazy ISOs should not be ignored. Here is an ISO 32,000 equivalent image from an IQ3 100mp (ISO12,800 marked on camera, with a ~1.5 stop push in post):View attachment 126146

Most of the grain in this image is added in Capture One using the Film Grain tool. This image would NOT make a stellar 5 foot print (the noise/detail/tonal-smoothness/blotchiness when viewed at 100% or other large-print-size equivalent magnifications is pretty rough - it is ISO 32,000 after all) but it easily handled what I'd normally use a dSLR for in the past – quick shots that only need web resolution (this project was processed at 2000px wide) but which require high ISO.

So here's a left field idea. Shoot at 1600 and overexpose A LOT so that you get a lot of red blinking and a touch of pink blink on the speculars.

This evening I set the STC on a tripod and pointed it at some remote controls (far too embarrassing to post here!) and shot it at 50 thru 1600 ISO at the same shutter speed and aperture. 50 was underexposed, the correct exposure was probably between 100 and 200 and 1600 was horribly overexposed. Until I pulled the files into C1 and adjusted the exposure slider so as to make them all look about right.

And the winner was the overexposed 1600 frame because, with exposure pulled back in post, the brightest bits of the buttons and the sheen on the steel were not blown - whereas on the other frames, there were unrecoverable highlights. The 1600 file had no more noise than the 50 file, or not that I could see.

I don't know why, but I do know that it was therefore the best frame.......

 

[ErikKaffehr]

Hi Tim,

The figure below explains a lot:


It says that ISO 50 and ISO 100 settings are the same, but ISO 100 may underexpose to protect highlights.

So, ISO 100 is just ISO 50 underexposed one stop. Or say exposing 0+EV at 50 ISO and exposing +1EV at 100 ISO would give the same result.

The interesting part is that the raw data are not affected at ISO settings above 3200 ISO. Exposure is shifted so mid tones get more noisy, but the capability to capture highlight detail is expended.

I would recommend checking out the raw data with RawDigger. It helps a lot with understanding how the camera works.

The histogram shown in raw developers like C1 or LR is always shown after exposure offset and tone so they are highly unreliable.

It seems that Lightroom does not handle the raw files from the X1D correctly, throwing away the highlight information in high ISO images. That very probably explains what you see. I would hope that Adobe fixes this soon. I would also hope that other vendors take a similar approach to raw data to the one taken by Hasselblad and Phase One, leaving the data alone but adding an underexposure tag. That's the smart thing to do.

Best regards
Erik

So here's a left field idea. Shoot at 1600 and overexpose A LOT so that you get a lot of red blinking and a touch of pink blink on the speculars.

This evening I set the STC on a tripod and pointed it at some remote controls (far too embarrassing to post here!) and shot it at 50 thru 1600 ISO at the same shutter speed and aperture. 50 was underexposed, the correct exposure was probably between 100 and 200 and 1600 was horribly overexposed. Until I pulled the files into C1 and adjusted the exposure slider so as to make them all look about right.

And the winner was the overexposed 1600 frame because, with exposure pulled back in post, the brightest bits of the buttons and the sheen on the steel were not blown - whereas on the other frames, there were unrecoverable highlights. The 1600 file had no more noise than the 50 file, or not that I could see.

I don't know why, but I do know that it was therefore the best frame.......

 

[tashley]

Hi Tim,

The figure below explains a lot:
View attachment 126163

It says that ISO 50 and ISO 100 settings are the same, but ISO 100 may underexpose to protect highlights.

So, ISO 100 is just ISO 50 underexposed one stop. Or say exposing 0+EV at 50 ISO and exposing +1EV at 100 ISO would give the same result.

The interesting part is that the raw data are not affected at ISO settings above 3200 ISO. Exposure is shifted so mid tones get more noisy, but the capability to capture highlight detail is expended.

I would recommend checking out the raw data with RawDigger. It helps a lot with understanding how the camera works.

The histogram shown in raw developers like C1 or LR is always shown after exposure offset and tone so they are highly unreliable.

It seems that Lightroom does not handle the raw files from the X1D correctly, throwing away the highlight information in high ISO images. That very probably explains what you see. I would hope that Adobe fixes this soon. I would also hope that other vendors take a similar approach to raw data to the one taken by Hasselblad and Phase One, leaving the data alone but adding an underexposure tag. That's the smart thing to do.

Best regards
Erik

Thank you Erik, but I don't think that's the entire story because the blown highlights were visible at every ISO apart from 1600.

So with the same aperture and the same shutter speed, just ISO 1600 was unaffected. I think something might be going on in addition to what you described above...