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Author Topic: Large amount of P1 backs for sales  (Read 15507 times)

Graham Welland

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Hi,

Bernard found that AF is not accurate enough to achieve critical focus. That kind of issue is never mentioned on forums or in tests.

Diglloyd (Lloyd Chambers) has tested the Hassy some years ago and did not complain about focusing. That is more like an exception.

Best regards
Erik

There seems to be here a lot of pontification from folks about gear that they neither own or shoot ... just saying. My XF is a slow focus camera but it does focus.
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Graham

Bo_Dez

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Re: Large amount of P1 backs for sales
« Reply #161 on: May 18, 2018, 07:58:51 AM »

Exactly. My H focuses very accurately.

I don't expect it focus as fast as a 35mm camera, nor do I expect it to capture a moving subject as easily.
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ErikKaffehr

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Re: Large amount of P1 backs for sales
« Reply #162 on: May 18, 2018, 12:30:23 PM »

Hi,

This posting may illustrate AF accuracy a bit: http://forum.luminous-landscape.com/index.php?topic=123230.msg1027538#msg1027538

The topic is here: http://forum.luminous-landscape.com/index.php?topic=123230.0

Best regards
Erik



Exactly. My H focuses very accurately.

I don't expect it focus as fast as a 35mm camera, nor do I expect it to capture a moving subject as easily.
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Bo_Dez

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Re: Large amount of P1 backs for sales
« Reply #163 on: May 18, 2018, 12:49:43 PM »

Hi,

This posting may illustrate AF accuracy a bit: http://forum.luminous-landscape.com/index.php?topic=123230.msg1027538#msg1027538

The topic is here: http://forum.luminous-landscape.com/index.php?topic=123230.0

Best regards
Erik

I started using the Hasselblad H in 2005. How about you?
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ErikKaffehr

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Re: Large amount of P1 backs for sales
« Reply #164 on: May 18, 2018, 03:26:46 PM »

Hi,

You have an interesting point...

On the other hand, the H6D owner did have a problem and I suggested a solution that actually worked: http://forum.luminous-landscape.com/index.php?topic=123230.msg1027810#msg1027810

You can check some of the postings near by.

It is very clear that Bernard, who also owns a H6D finds that focusing the Hasselblad is tricky with off axis subjects. It seem that magnified live view works well, but it takes careful work.

This is actually the point I would like to make. Things like that should be discussed before suggesting that someone would spend like 35k$US on gear.

Another point, that I think that Bernard also makes, is that we have 100 MP around the corner from both Hasselblad and Fuji. At the present state, both systems offer CDAF with many focusing points that are accurate. The lenses for both systems are probably optimized for 100 MP, Fuji says so and measurements by Jim Kasson certainly confirm Fuji's statements.

I have not seen testing like Jim's for the X1D, but Hasselblad's MTF data tells a similar story.

Just to say, I made my living as an engineer, mostly simulating nuclear power plants. In science/engineering we are used to rely on work made by others. So, for me it is quite natural to read available info and make estimates based on existing work.

My MFD experience is with the P45+ on Hasselbad 555/ELD, I bought it 2013 and I still have it, although it sees very little use. Obviously, I recognize that the H6D is a very different animal.

Best regards
Erik

I started using the Hasselblad H in 2005. How about you?
« Last Edit: May 18, 2018, 04:29:02 PM by ErikKaffehr »
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Erik Kaffehr
 

eronald

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Re: Large amount of P1 backs for sales
« Reply #165 on: May 18, 2018, 03:43:52 PM »


Just to say, I made my living as an engineer, mostly simulating nuclear power plants. In science/engineering we are used to rely on work made by others. So, for me it is quite natural to read available info and make estimates based on existing work.


Yes, and when we rely on the work of others we usually deduct an "optimism factor" from specs on a datasheet, eg. MTF graphs from the manufacturer which are often computed rather than measured MTF, or else from a handpicked perfect lens sample.

Edmund
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ErikKaffehr

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Re: Large amount of P1 backs for sales
« Reply #166 on: May 18, 2018, 04:08:15 PM »

Hi Ronald,

I would agree with you, but I would make two points.

  • If Hasselblad releases MTF data for a HC-lens or an XD-lens, both will probably be hand picked.
  • The Swedish monthly "Foto" did make MTF testing using Hasselblad's MTF equipment and got results very similar to the MTF data that Hasselblad published.

The question we may ask: is there any better information than that?

Jim Kasson has done a lot of testing on Fuji GFX lenses and found them extraordinary. Jim did compare Fuji glass to some of his samples of HC and Hasselblad CF glass. The GFX lenses played in another division. My guess is that the X1d lenses compete head on with Fuji's GFX lenses. But, that is just a guess.

Best regards
Erik




Yes, and when we rely on the work of others we usually deduct an "optimism factor" from specs on a datasheet, eg. MTF graphs from the manufacturer which are often computed rather than measured MTF, or else from a handpicked perfect lens sample.

Edmund
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BernardLanguillier

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Re: Large amount of P1 backs for sales
« Reply #167 on: May 18, 2018, 05:36:26 PM »

Exactly. My H focuses very accurately.

Mine does also, on static subjects located reasonnably close to the center of the frame.

On the Fuji vs X1d lenses, I have no first hand experience, but Lloyd Chambers seems to think that the Hasselblad lenses have much less sample variation.

Cheers,
Bernard
« Last Edit: May 18, 2018, 05:39:38 PM by BernardLanguillier »
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eronald

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Re: Large amount of P1 backs for sales
« Reply #168 on: May 18, 2018, 11:04:47 PM »

Hi Ronald,

I would agree with you, but I would make two points.

  • If Hasselblad releases MTF data for a HC-lens or an XD-lens, both will probably be hand picked.
  • The Swedish monthly "Foto" did make MTF testing using Hasselblad's MTF equipment and got results very similar to the MTF data that Hasselblad published.

The question we may ask: is there any better information than that?

Jim Kasson has done a lot of testing on Fuji GFX lenses and found them extraordinary. Jim did compare Fuji glass to some of his samples of HC and Hasselblad CF glass. The GFX lenses played in another division. My guess is that the X1d lenses compete head on with Fuji's GFX lenses. But, that is just a guess.

Best regards
Erik

Hi Erik,

 My first name is Edmund :)

 One would expect the new Fuji lenses to be better than the H, they are after all from the same manufacturer  as the "Hassy" lenses, and much younger. That with 100MP crop resolution the Hassy H lenses will be nearing the end of their useful design life shows how well the system was initially specced and manufactured.

 I expect the H system will be retired as soon as the lens collection for the XD is built up completely.

Edmund
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Jim Kasson

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Re: Large amount of P1 backs for sales
« Reply #169 on: May 18, 2018, 11:56:11 PM »

One would expect the new Fuji lenses to be better than the H, they are after all from the same manufacturer as the "Hassy" lenses, and much younger.

And have to cover a smaller image circle.

jim

eronald

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Re: Large amount of P1 backs for sales
« Reply #170 on: May 19, 2018, 12:04:58 AM »

And have to cover a smaller image circle.

jim

Yes, this is the part I don't quite understand, I would have expected Fuji to leave more space between full-frame 35 and their offering.

Edmund
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ErikKaffehr

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Re: Large amount of P1 backs for sales
« Reply #171 on: May 19, 2018, 12:40:43 AM »

Hi Edmund,

This posting on DPReview is quite interesting: https://www.dpreview.com/forums/post/61122175

Fuji probably went with the 44x33 mm sensor from Sony because they wanted to build the camera around an off the shelf sensor that was available at a cost allowing for a product at cost that would sell in volume.

Best regards
Erik



Yes, this is the part I don't quite understand, I would have expected Fuji to leave more space between full-frame 35 and their offering.

Edmund
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Bo_Dez

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Re: Large amount of P1 backs for sales
« Reply #172 on: May 19, 2018, 04:05:38 AM »

Hi,

You have an interesting point...

On the other hand, the H6D owner did have a problem and I suggested a solution that actually worked: http://forum.luminous-landscape.com/index.php?topic=123230.msg1027810#msg1027810

You can check some of the postings near by.

It is very clear that Bernard, who also owns a H6D finds that focusing the Hasselblad is tricky with off axis subjects. It seem that magnified live view works well, but it takes careful work.

This is actually the point I would like to make. Things like that should be discussed before suggesting that someone would spend like 35k$US on gear.

Another point, that I think that Bernard also makes, is that we have 100 MP around the corner from both Hasselblad and Fuji. At the present state, both systems offer CDAF with many focusing points that are accurate. The lenses for both systems are probably optimized for 100 MP, Fuji says so and measurements by Jim Kasson certainly confirm Fuji's statements.

I have not seen testing like Jim's for the X1D, but Hasselblad's MTF data tells a similar story.

Just to say, I made my living as an engineer, mostly simulating nuclear power plants. In science/engineering we are used to rely on work made by others. So, for me it is quite natural to read available info and make estimates based on existing work.

My MFD experience is with the P45+ on Hasselbad 555/ELD, I bought it 2013 and I still have it, although it sees very little use. Obviously, I recognize that the H6D is a very different animal.

Best regards
Erik

The OP in your link was shooting a portrait with a large 100MP medium format camera, and a wide open 150mm lens, with no experience of doing so. With all respect, I'm not surprised he had difficulty in getting sharp pictures.
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ErikKaffehr

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Re: Large amount of P1 backs for sales
« Reply #173 on: May 19, 2018, 09:02:29 AM »

Hi,

The guy just spent a few tens of thousand dollars on an system that is supposed to deliver 100 MP of detail, having a focusing system that is supposed to compensate for camera rotation.

We don't have 100 MP on mirrorless yet, although Phase already uses the new sensor for aerial imaging.

The existing mirrorless systems allow you to select the focusing point freely, so there is no need for True Focus.

One interesting issue that was quite obvious in Neil's images that the 150 mm lens is not well corrected for axial chroma. The straight image with True Focus activated has green fringing:


The next image with True Focus engaged and a camera rotation has magenta fringing:


After that it seems that Neil tried magnified live view and got no fringing:


These samples show that the HC 150 lens is not well corrected for axial chroma and that focusing may not be accurate enough to avoid axial chroma.

An interesting question may be: Would Neil achieved a better image with a 50MP camera like the X1D or the GFX?

Jim Kasson has run a lot of tests on his GFX lenses and it seems that they are very well corrected. My guess would be that X1D lenses perform at the same level.  It may be that GFX lenses have more sample variation than X1D lenses, but it seems that all lenses Jim got were pretty good.

It also seems that most lenses are pretty decent. Obviously, no lens can exceed the design criteria. Jim Kasson has developed a lens screening method. I put some of my lenses trough it and all three were pretty OK.

https://blog.kasson.com/lens-screening-testing/examples/good-100mm-lens-on-p1-p45/
https://blog.kasson.com/lens-screening-testing/examples/ok-60mm-lens-on-phase-one-p45/

The third lens was the Sigma 24-105/4 Art at three different focal lengths. I don't think that Jim Kasson has a public link to that lens, but he felt it was quite OK.

To sum it up a bit...
  • I don't think that old film era lens designs are a good match for today's digital sensors. They may deliver good results, but axial chroma is probably not corrected well enough.
  • Modern focusing systems allow for critical focus anywhere over the frame. Older systems have a single focus point and using that focus point for of axis focusing does induce an error. Hasselblad has developed a complex solution around the issue with "True Focus".
  • Modern, EVF based, systems use the sensor itself for focusing. A simple and good solution.
  • Both the X1D and the GFX are designed around the sensor. In all probability they are designed around 2018 sensor technology /li]
I would argue that it makes a lot of sense for newcomers to MFD to spend their money on systems that are designed for 2018 sensor technology than on systems designed for film around the turn of centuries.

Best regards
Erik


The OP in your link was shooting a portrait with a large 100MP medium format camera, and a wide open 150mm lens, with no experience of doing so. With all respect, I'm not surprised he had difficulty in getting sharp pictures.
« Last Edit: May 19, 2018, 09:32:08 AM by ErikKaffehr »
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Erik Kaffehr
 

Bo_Dez

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Re: Large amount of P1 backs for sales
« Reply #174 on: May 19, 2018, 09:20:49 AM »

Hi,

The guy just spent a few tens of thousand dollars on an system that is supposed to deliver 100 MP of detail, having a focusing system that is supposed to compensate for camera rotation.

We don't have 100 MP on mirrorless yet, although Phase already uses the new sensor for aerial imaging.

The existing mirrorless systems allow you to select the focusing point freely, so there is no need for True Focus.

One interesting issue that was quite obvious in Neil's images that the 150 mm lens is not well corrected for axial chroma. The straight image with True Focus activated has green fringing:

No such camera compensates for a lack of experience. It does deliver 100MP of detail, he just needs to learn how to work with it properly.

The 150 is a 16 year old lens, it was never designed to work with a 100MP sensor but I have found it to work surprisingly well, even so.

I use the 120mm II over the 150mm for a critical applications. But the 150mm has a very nice rendering nonetheless and it's quick and easy to get rid of the CA.
« Last Edit: May 19, 2018, 09:38:14 AM by Bo_Dez »
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ErikKaffehr

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Re: Large amount of P1 backs for sales
« Reply #175 on: May 19, 2018, 09:48:14 AM »

Hi,

Getting rid of axial chroma is pretty much impossible. What you can do is to desaturate the affected colors, essentially turning the edges into monochrome.

It may not be a problem if you don't view the images critically. But, why would you spend a lot of k$US on image quality if you don't look close?!

Admittedly, my experience is with the P45+ and Hasselblad V-lenses. Also, I guess that I have not spent more than 25k$US on MFD. But from where I stand, larger than 44x33 mm MFD is old technology. Going with that technology is just wasting money, IMHO.

Spending on modern technology, like GFX and X1D, may make some sense in some cases. Spending on old technology is in my humble opinion a very bad advice.

Best regards
Erik


No such camera compensates for a lack of experience. It does deliver 100MP of detail. He just needs to learn how to work with it properly.

The 150 is a 16 year old lens, it was never designed to work with a 100MP sensor but I have found it to work surprisingly well, even so.

I use the 120mm II over the 150mm for a critical applications. But the 150mm has a very nice rendering nonetheless and it's quite quick and easy to get rid of the CA.
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Jim Kasson

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Re: Large amount of P1 backs for sales
« Reply #176 on: May 19, 2018, 10:00:52 AM »

Yes, this is the part I don't quite understand, I would have expected Fuji to leave more space between full-frame 35 and their offering.

They only had two CMOS sensors bigger than 24x36mm to pick from, didn't they? And Fuji's presence in smaller than MF is in APS-C. It's a pretty big step from that.

Jim

BJL

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Large amount of P1 backs for sales—and why is 44x33mm a new standard?
« Reply #177 on: May 19, 2018, 10:29:46 AM »

I would have expected Fuji to leave more space between full-frame 35 and their offering.
As others shave said, FujiFilm did not really make this decision: the big end of sensor formats has for whatever reason converged on three sizes: the two roughly matching film formats (36x24mm and 54x40mm) and one in between, 44x33mm.

Why this choice for the new intermediate size? It is fairly close to midway between 44x33 and 54x40, but maybe it also relates to the fabrication constraint that the maximum field size on the equipment used to make these sensors is the industry-standard 26x33mm. That might mean that a short edge of 33mm is the largest that allows fabrication by stitching in one direction only, with as few at two  fields, whereas any larger format requires stitching in two directions and at least four fields, which could lead to a significantly slower process and significantly more rejects, driving prices up substantially.

P. S. I also agree with Jim Kasson that the gap in Fujifilm's offerings from 24x16 to 44x33 is big enough: bigger percentage-wise than the film format gap from 36x24mm to the 56x42mm of "645".
« Last Edit: May 19, 2018, 10:36:34 AM by BJL »
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eronald

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So Sony sell everybody including themselves 24x36 and Fuji are competing with their only supplier.

And the 24x36 sensor versions have the features that make computational photography tick,well  before Fuji gets them - eg pdaf, eye focus, fast backing memory for handheld superresolution, global shutter, just look at everything the A7 series can do.

Edmund

As others shave said, FujiFilm did not really make this decision: the big end of sensor formats has for whatever reason converged on three sizes: the two roughly matching film formats (36x24mm and 54x40mm) and one in between, 44x33mm.

Why this choice for the new intermediate size? It is fairly close to midway between 44x33 and 54x40, but maybe it also relates to the fabrication constraint that the maximum field size on the equipment used to make these sensors is the industry-standard 26x33mm. That might mean that a short edge of 33mm is the largest that allows fabrication by stitching in one direction only, with as few at two  fields, whereas any larger format requires stitching in two directions and at least four fields, which could lead to a significantly slower process and significantly more rejects, driving prices up substantially.

P. S. I also agree with Jim Kasson that the gap in Fujifilm's offerings from 24x16 to 44x33 is big enough: bigger percentage-wise than the film format gap from 36x24mm to the 56x42mm of "645".
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Bo_Dez

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Re: Large amount of P1 backs for sales
« Reply #179 on: May 19, 2018, 11:20:58 AM »

Hi,

Getting rid of axial chroma is pretty much impossible. What you can do is to desaturate the affected colors, essentially turning the edges into monochrome.

It may not be a problem if you don't view the images critically. But, why would you spend a lot of k$US on image quality if you don't look close?!

Admittedly, my experience is with the P45+ and Hasselblad V-lenses. Also, I guess that I have not spent more than 25k$US on MFD. But from where I stand, larger than 44x33 mm MFD is old technology. Going with that technology is just wasting money, IMHO.

Spending on modern technology, like GFX and X1D, may make some sense in some cases. Spending on old technology is in my humble opinion a very bad advice.

Best regards
Erik

You have no idea what you are talking about.

« Last Edit: May 19, 2018, 11:53:48 AM by Bo_Dez »
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