Mamiya 7 and IQ180 in black and white

[timparkin]

I'm currently working with Lenny Eiger to get some scans of the film we shot for the big camera comparison done (using an Aztek Premiere 8000dpi scanner) and I thought I'd show a quick preview of the Mamiya 7 T-Max scan file alongside the IQ180 ... The Mamiya stands up fairly well. We've obviously got a fair bit of halation in the film and fundamentally it's a very different aesthetic but the fact it's in the ballpark is quite impressive. I've clipped the highlights on the film scan a little by the way but then the jpg compression in the highlights is making a mess of things too..

http://gbl.bz/mamiya7

http://gbl.bz/iq180-alpa

Tim

 

[Jorgen Udvang]

Is that T-Max 100 or 400?

 

[timparkin]

Is that T-Max 100 or 400?

100

 

[cunim]

Thanks for the comparison, Tim. Very instructive.

Peter

 

[Shashin]

We've obviously got a fair bit of halation in the film...

Where? I looked at the film image and could not see any evidence of halation. It would be a rather odd thing to see with a modern emulation and camera.

Thanks for the post. The Mamiya 6 was a real favorite of mine and it is interesting to see the comparison.

 

[Jorgen Udvang]

There's something I don't understand here:
- If the film image is scanned at 8,000dpi, it's either downsized or cropped. An 8,000dpi scan of a 6x7cm negative gives 22,000 pixels longest side.

- When I look at some of my scans of 35mm Delta 100, a film that I thought would be similar to T-Max 100, I don't get the same level of detail as you do with your scan, but still far too much considering the huge difference in film format and the fact that I scanned my negs on a 10 year old Epson 3200 flatbed scanner (4,500 pixels longest side).

There's something I don't understand here.

 

[ClydeR]

I agree, something about this is confusing. I scan TMAX 100 with a Imacon PIII and get less grain, more detail and better contrast than this image shows (assuming the image is not cropped). Lenny has excellent credentials, I fully expect his scans to smoke mine.

I'd like to see the results of this comparison, but don't understand what's going on well enough for this comparison to work for me.

Later,

Clyde

 

[timparkin]

Here's the original test to show the context of the sample you can see

Big Camera Comparison – On Landscape

We'll post more when we've finished the proper comparison...

 

[Jorgen Udvang]

Something must have gone wrong during the scan of the Mamiya film file. Here, on the 4x5 file (Delta 100), the scan holds up very well compared to the microscope view:

But with the M7 example (T-Max 100), the resolution test is falling apart completely when scanned compared to the microscope view:

 

[SCHWARZZEIT]

As far as I understand Tim's test, the trumpet chart crops are scaled to the same size as the 4000 ppi scan of the 8x10" reference which puts the Mamiya 7 trumpet at almost 16000 ppi. I agree there are some strange artifacts in that scaled 8000 ppi scan. A good scan should look better than this. On the other hand Lenny's new scan does look really good. If you open the file you can see that it's an 8000 ppi crop of a small area on the film. The contrast of the Mamiya 7 TMX film seems rather low. I'd expext TMX to have more punch.
My personal interpretation is that for higher contrast details the 6x7 film has a slight advantage in resolution over the IQ180 but for mid to low contrast the IQ180 is better and the overall rendition is much cleaner.

Tim, did you process Lenny's 8000 ppi scan in terms of noise reduction and sharpening?

-Dominique

 

[timparkin]

Hi,

You need to take into account that the photographs have been framed the same on the different cameras - so the 4x5 has over twice the linear resolution than the 6x7 because it's using over four times the surface area of film.

and yes the area is quite a dramatic crop (otherwise the scan would only need to be about 2000dpi.

I agree, something about this is confusing. I scan TMAX 100 with a Imacon PIII and get less grain, more detail and better contrast than this image shows (assuming the image is not cropped). Lenny has excellent credentials, I fully expect his scans to smoke mine.

If you think so I'd be happy to send you some of the film.. Have a check of the test conditions etc and then if you still think you can get less grain and more detail and more contrast, just send me your address ...

Now we can play with aperture to reduce the grain but at the cost of some resolution - that is an aspect we are looking into.

Where? I looked at the film image and could not see any evidence of halation. It would be a rather odd thing to see with a modern emulation and camera.

Have a look at the circular aperture in the hassleblad - on the IQ180 you get a nice contrast edge whereas with the Mamiya 7 you get a bleed from the centre aperture into the surrounding dark shades.


Tim

 

[timparkin]

As far as I understand Tim's test, the trumpet chart crops are scaled to the same size as the 4000 ppi scan of the 8x10" reference which puts the Mamiya 7 trumpet at almost 16000 ppi. I agree there are some strange artifacts in that scaled 8000 ppi scan. A good scan should look better than this. On the other hand Lenny's new scan does look really good. If you open the file you can see that it's an 8000 ppi crop of a small area on the film. The contrast of the Mamiya 7 TMX film seems rather low. I'd expext TMX to have more punch.
My personal interpretation is that for higher contrast details the 6x7 film has a slight advantage in resolution over the IQ180 but for mid to low contrast the IQ180 is better and the overall rendition is much cleaner.

Tim, did you process Lenny's 8000 ppi scan in terms of noise reduction and sharpening?

-Dominique

Hi Dominique - yes I did a bit of post processing for noise and also used a large area unsharp mask to help with the halation (40px radius about 20% amount). And some sharpening too.

Tim

 

[Jorgen Udvang]

I agree there are some strange artifacts in that scaled 8000 ppi scan. A good scan should look better than this.

-Dominique

It would of course be interesting to know where the artifacts come from, since they are not there in the microscope view. From what I can gather, they influence the resolution of the image as a whole. Can it be the scanner setting or some mismatch between the grain structure of the film and/or the lens rendering with the scanner? It doesn't look like grain to me

 

[ClydeR]

and yes the area is quite a dramatic crop

If you think so I'd be happy to send you some of the film.. Have a check of the test conditions etc and then if you still think you can get less grain and more detail and more contrast, just send me your address ...

There's no need for that, the link provides the context for the test, the image is a crop. I've figured that I get an equivalent of a bit under 40Mp from the Mamiya 7/PIII combination, which seems reasonably in line with your results (a bit lower resolution than your 4000 dpi scan results). Lenny's scans are better than mine, just what I'd expect.

Interesting test, thanks.

Later,

Clyde

 

[timparkin]

It would of course be interesting to know where the artifacts come from, since they are not there in the microscope view. From what I can gather, they influence the resolution of the image as a whole. Can it be the scanner setting or some mismatch between the grain structure of the film and/or the lens rendering with the scanner? It doesn't look like grain to me

If you mean the vertical spiking, it's jitter in the system (possibly in the belt/encoding disk) this causes slightly offsets in each vertical line scan. I have thought about using a single line horizontally as a 'reference' and to 'fix' these using this (should be possible as long as the offset is consistent along a vertical column but I have a feeling it's not).

At worst it's a slightly speed up/slow down of the rotation as you go through the scan.

 

[Jorgen Udvang]

If you mean the vertical spiking, it's jitter in the system (possibly in the belt/encoding disk) this causes slightly offsets in each vertical line scan. I have thought about using a single line horizontally as a 'reference' and to 'fix' these using this (should be possible as long as the offset is consistent along a vertical column but I have a feeling it's not).

At worst it's a slightly speed up/slow down of the rotation as you go through the scan.

I see, but why are we seeing this only in the Mamiya 7 images? Is it a randomly occuring problem?

 

[timparkin]

I see, but why are we seeing this only in the Mamiya 7 images? Is it a randomly occuring problem?

Because they are the only 8000dpi scans... (the original 8000dpi scans were done 90 degrees and so the variance is along the trumpet shape rather than across it.

Tim

 

[Jorgen Udvang]

Because they are the only 8000dpi scans... (the original 8000dpi scans were done 90 degrees and so the variance is along the trumpet shape rather than across it.

Tim

How about this one?

You see, my point is that, while on the 4x5, the 8000dpi scan seems to improve on the microscope view, while on the Mamiya scan, it seems to be the other way around, and quite dramatically so. It might be me who don't understand the methodology her (wouldn't be the first time ), but still...

 

[timparkin]

How about this one?

....

You see, my point is that, while on the 4x5, the 8000dpi scan seems to improve on the microscope view, while on the Mamiya scan, it seems to be the other way around, and quite dramatically so. It might be me who don't understand the methodology her (wouldn't be the first time ), but still...

I'm afraid I can't see your point as it doesn't look like the 8000dpi scan improves on the 4x5 view. In fact you'd be hard pushed to say that that 8000dpi scan improves on the 4000dpi scan.

If you look at the microscope view you can clearly see horizontal lines up to 12 and maybe 13. On the 4000/8000 scan they stop at 10 maybe 11.

Of course the scan of 4x5 will get more of the full amount out because of the resolution limit of the lenses means you can't put as fine a line down on film, which makes it easier to read by the scanner.

With the Mamiya 7, the lenses can put down such fine detail that the scanner has difficultly in reading it. The 8000dpi scanner that Lenny has manages better than any other scanner I've tried yet though!

 

[Jorgen Udvang]

The 8000dpi scan of the 4x5 is more contrasty than the 4000dpi. In my view, it also shows more detail, although some of that detail is grain. IN my view, scanning to a level where grain becomes visible is an advantage, since it also shows the true character of the film, but no everybody will agree on that.

What is important is that, since there are strong artifacts on the 8000dpi scan of the Mamiya 7 image, that scan can't be trusted and makes it irrelevant for the comparison. That's a pity, considering all the work that must have gone into this and since for some of us, finding the resolution potential of medium format film gives us an indication of where the limit for our cameras are, at least for the film used in this test.