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Author Topic: Is focusing more critical with a MFDB than film?  (Read 5762 times)

VanKou

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Is focusing more critical with a MFDB than film?
« on: April 05, 2008, 01:17:47 pm »

Hi:

I just picked up a V96C for a Hasselblad V and I am seeing that focusing should be more accurate than film.  Is this what other more experienced MFDB users believe?
Are there any suggestions (especially from other Manual focus camera shooters) as to how to focus more accurately and effectively?

Thanks
VanKou
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Dustbak

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Is focusing more critical with a MFDB than film?
« Reply #1 on: April 05, 2008, 02:13:13 pm »

Yes.

Part is probably due to the fact that nowadays we look at screens at 100% but I am pretty sure it is not all perception or shifting perception of acceptable sharpness.

Good news is that you get the hang of it eventually and your images have never been so sharp and well focussed.

For me, I found the V very difficult to focus even with Brightscreen & Acute Matte. Despite the big screen it was very hard to see where exactly focus was.

I now use H and some other more exotic stuff.
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ErikKaffehr

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Is focusing more critical with a MFDB than film?
« Reply #2 on: April 05, 2008, 04:06:30 pm »

Yes!

Main reasons:

- Sensor is perfectly flat, film has never been.
- Sensor lacks depth
- It is easy to look at finest detail, just click actual pixels. You would need a microscope to that with film. I actually have done that...

Solutions:

- Check that focus screen and sensor is well aligned.
- Be careful
- Stop down but not beyond 1/11 or so

Digital is not more demanding then analogue in any way but is making problems much more obvious as far less errors are masked in the processing chain.

Best regards

Erik

Quote
Hi:

I just picked up a V96C for a Hasselblad V and I am seeing that focusing should be more accurate than film.  Is this what other more experienced MFDB users believe?
Are there any suggestions (especially from other Manual focus camera shooters) as to how to focus more accurately and effectively?

Thanks
VanKou
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« Last Edit: April 05, 2008, 04:08:12 pm by ErikKaffehr »
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Erik Kaffehr
 

Justinr

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Is focusing more critical with a MFDB than film?
« Reply #3 on: April 05, 2008, 06:12:53 pm »

Quote
Sensor is perfectly flat, film has never been

I was told by a Phase One salesman that sensors can vary by up to 25 microns in height due to 'lumps' in the glue that stick them to the base plate.

Producing an absolutely flat surface or straight line (which is the same thing) is quite an engineering challenge and such things are measured in how close they come to being perfect, not that they actually ever are.

Justin.
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rovanpera

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Is focusing more critical with a MFDB than film?
« Reply #4 on: April 06, 2008, 05:06:25 am »

the digital sensor is smaller than film, so you are magnifying the image the lens produces more. So what is "acceptable" sharpness in film may not be acceptable anymore in digital. It's like judging the focus point and DOF of a print from 2m distance versus 0.5m distance.

The DOF scale in lenses is film based, so to use it with DB, you have to compensate the aperture, +1 stop at least. So if the scale shows you to use f/8, you leave the focus at that but dial f/11 for aperture.
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Bernd B.

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Is focusing more critical with a MFDB than film?
« Reply #5 on: April 06, 2008, 08:12:46 am »

With Hasselblad V and a digital back I found that using an Acute Matte "D" screen  with a new version WLF or a HM2 magnifying hood #72524 gave stunning acuracy even when shooting aperture open.

With a prism finder acuracy wasn´t´that good. I just couldn´t tell exactly if it was focussed perfectly or not.

BTW: The 80mm might have been a good lens wide open for film. But with digital it is only good when stopped down.

Bernd
« Last Edit: April 06, 2008, 08:13:18 am by Bernd B. »
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Gary Yeowell

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Is focusing more critical with a MFDB than film?
« Reply #6 on: April 06, 2008, 08:24:04 am »

I also found that my Hassy 503CW with Acute Matte D screen when used with my Phase P20 with all lenses (40CFEIF/60CF/100CFI/180CFI) was absolutely spot on for wide open focus. I have a much harder time getting my Canon 1DS3 focussed with lenses wide open, with the likes of the 35f1.4 and 85f1.2, but when done they are very sharp.

Gary.
« Last Edit: April 06, 2008, 08:24:52 am by Gary Yeowell »
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buzzski

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Is focusing more critical with a MFDB than film?
« Reply #7 on: April 06, 2008, 08:56:21 am »

Quote from: Bernd B.,Apr 6 2008, 01:12 PM
With Hasselblad V and a digital back I found that using an Acute Matte "D" screen  with a new version WLF or a HM2 magnifying hood #72524 gave stunning acuracy even when shooting aperture open.

Hi there, I'm using one of the first generation acute matte screens - probably at least 15 years old now. Is the "D" screen that much different? I too struggle a bit, especially with the 80mm lens to get pin-sharp every time so any aid would be a good one. Thanks, Craig
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Bernd B.

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Is focusing more critical with a MFDB than film?
« Reply #8 on: April 06, 2008, 09:19:10 am »

With the Acute Matte "D" it works better, after my experience. I ´ve got both.

With the 80mm it SEEMS difficult because it IS impossible wide open. The lens is just not sharp enough at 2,8 and 4.

If you want to shoot wide open in that range get youself a 100mm.

Bernd






Hi there, I'm using one of the first generation acute matte screens - probably at least 15 years old now. Is the "D" screen that much different? I too struggle a bit, especially with the 80mm lens to get pin-sharp every time so any aid would be a good one. Thanks, Craig
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BJNY

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Is focusing more critical with a MFDB than film?
« Reply #9 on: April 06, 2008, 09:32:07 am »

I've used the AFi/Hy6 on three separate occassions, and my eyes couldn't be happier with how clear the focusing screen is.  I've owned or used every brand of MF SLR extensively, and I'm more sure of the focus than ever.
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Guillermo

buzzski

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Is focusing more critical with a MFDB than film?
« Reply #10 on: April 07, 2008, 08:40:32 am »

Quote from: Bernd B.,Apr 6 2008, 02:19 PM
With the Acute Matte "D" it works better, after my experience. I ´ve got both.

With the 80mm it SEEMS difficult because it IS impossible wide open. The lens is just not sharp enough at 2,8 and 4.

If you want to shoot wide open in that range get youself a 100mm.

Bernd
Hi there, I'm using one of the first generation acute matte screens - probably at least 15 years old now. Is the "D" screen that much different? I too struggle a bit, especially with the 80mm lens to get pin-sharp every time so any aid would be a good one. Thanks, Craig
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[/quote]


I've just visited my local Calumet and compared an off the shelf 503CWD focussing screen with my own. It had a split which is an advantage but I didn't see any difference in ease of focus overall. Could it be that this isn't an acute matte D screen? The Blad website is of no use in determining this. Anyone with knowledge of this would be great. If there is a difference then I'd go for it. Thanks in advance, Craig
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