Hasselblad Focusing Tips/Tricks

[mshchem]

Oh I know how to load the blad backs.

 

[nickandre]

Alright not to be bamboozled, I went ahead and did a second set of focus test exposures but this time I took a picture in the finder for each so I could compare. I do not believe the camera is front-focusing, I think I'm just inept. I consistently see the old ground glass giving a little more accurate focusing for my use.

For the curious it's a pretty good comparison of the AM and AMD screens:

Note how the AM exaggerates the DoF:

versus AMD:

 

[Sirius Glass]

Alright not to be bamboozled, I went ahead and did a second set of focus test exposures but this time I took a picture in the finder for each so I could compare. I do not believe the camera is front-focusing, I think I'm just inept. I consistently see the old ground glass giving a little more accurate focusing for my use.

For the curious it's a pretty good comparison of the AM and AMD screens:

Note how the AM exaggerates the DoF:
View attachment 270117
versus AMD:
View attachment 270118

The difference looks to great, time for a CLA with emphasis on A.

 

[Pieter12]

Surprising how the viewfinder shows much more depth of field than the actual shots in both cases. Something is out of whack.

 

[nickandre]

Surprising how the viewfinder shows much more depth of field than the actual shots in both cases. Something is out of whack.

That's the Acute Matte screen. This is the reason they sell for a lot less than the Acute Matte D screen, since the exaggerate the DoF and make it more difficult to focus.

 

[nickandre]

The difference looks to great, time for a CLA with emphasis on A.

Should I send in the screens too? Do I just send in the entire kit?

 

[Sirius Glass]

Should I send in the screens too? Do I just send in the entire kit?

The entire body with the screens. The screens may not be sitting correctly on the camera.

 

[eli griggs]

Sorry for the exceptionally long post. My conclusions:


Depending on your vision, the waist level finder can be very accurate.

I am very near sighted and I've found lowering my eye, to make physical contact (no the ball of the eye) over the pop-up hood, no glasses, nor magnifier, allows me a very sharp vision for focusing.

This with zone focusing with pre-focus and the pre-set shutter and iris, at the minimum speed for the lens in use, are a good combo and do no need a tripod for normal sized prints.

If you need to use a slower speed or open F-stop, carry and use good ND filters and (always) a tripod or quality monopod for some support.

Using a basic film camera is kind of like using a Windows software.

There are always more than one way to do a job, you just need to discover what they are and make use of the on a regular basis.

Cheers.

1. Probably good move to get the whole kit CLA'd again.
2. Probably need to work on my technique and focusing combo (e.g. which focusing aids, prism vs WLF)
3. Some of this error is definitely mine, focusing tests suggest the possibility that focus is slightly front.
4. I should probably note that I have myopia, though I usually shoot with contacts in or glasses. Would be cool to find a -3 diopter for the WLF or prism.

I have the receipt from Hasselblad service center for a full overhaul of the camera. The back, camera, and AMD screen that I did the focusing tests with were overhauled together in 2019 and sat in the factory until I received it this year. I suppose I should reach out to Hasselblad service and see what they say -- if there was an error will they stand behind the service?

A few service questions:

1. In the US do people recommend I go with the factory service on the 200 series or is there a good independent shop? Ideally I'd like a reasonable turnaround.
2. I assume the whole kit needs to go together, right? Can they match two screens? Will they calibrate with the lens?

I ran focusing tests last night. Frames:

1. AMD: with split prism. Seems pretty close, perhaps near (sorry the paper is askew, focused in the center)
2. AMD: Using microprisms, towards the front side of what looked "in focus" - seems garbage
3. AMD: Using microprisms, towards the back side of what looked "in focus" - also seems garbage
4. AMD: Using the screen, perhaps near but close
5. AMD: Split prism on the line, really near
6. AMD: Using microprism over the "lake" text. Seems just about dead on.
7. AMD: microprism on the 6 on the ruler. Quite close, tad near.
8. AMD: microprism over the reflection on the speaker. Seems dead on.
9. GG: Switched to ground glass screen, dot pattern on 6, seems quite close but a tad near
10. GG: Ground glass (best I could), seems dead on.
11. GG: on the right side of the brick divet dead center.
12. AMD: right side of brick divet

Notes:

• It's hard for me to determine how much of this is my error versus calibration. It would appear there may be a small calibration issue to the front.
• I think the suggestion that the focusing aids aren't always good for precision focus may be on the right track.
• GG seems closer, not sure if that's just due to my finding it easier to use.
• AMD feels like it exaggerates DoF (see cell phone shot). I think I need to work on using the AMD.

I will master the art of the 110 f2 handheld, just you see



Which side is "up?" I think I may need to revisit relying on the microprism focusing aid in the WLF for my photos. I feel like I pull the focus back and fourth and have trouble figuring out what's "right."



Yeah I've been a bit frustrated with the microprism on the WLF. It seems to not be very precise. Do you use the split prism on the WLF or rely on the screen? Is WLF plus no focus aid a popular strategy?

 

[warden]

Alright not to be bamboozled, I went ahead and did a second set of focus test exposures but this time I took a picture in the finder for each so I could compare. I do not believe the camera is front-focusing, I think I'm just inept. I consistently see the old ground glass giving a little more accurate focusing for my use.

For the curious it's a pretty good comparison of the AM and AMD screens:

Note how the AM exaggerates the DoF:
View attachment 270117
versus AMD:
View attachment 270118

These images are fascinating. Thanks for sharing them.

 

[itsdoable]

Surprising how the viewfinder shows much more depth of field than the actual shots in both cases....

This is how the current lenticular or prismatic "bright" screens work. A GG will show something close to the correct DoF, the image of the GG screen attached above appears slightly back focused on the screen image, that and the Fresnel lens make the rear part of the image look sharper. The current bright screens redirect the scattered light towards the eye-point, making the screen look brighter, but at the same time affecting OOF blur and DoF. Take a look at focus screens available pre-autofocus, and you'll see that they made separate screen for small aperture telephoto lenses, and microscopes, fast primes and slower zooms. The reasons are that the F-stop determines the angle that the cone of light that hits the screen, and the lenticular/prismatic/fresnel components are optimized to redirect this cone of light. The Hasselblad screens were designed for f/2.8~f/4, where it works really well. Unfortunately these screen do not handle the 2/110's wider light cone, and only uses the central ~f/2.8 part, thus showing a D0F approximately ~f/2.8~4.

If you put a wax film GG screen (ie: BOS), you will see the DoF correctly - but the image will be relatively dim.

If you take a non-pro SLR, which were sold with moderately slow zooms, and put a fast prime on it, you will see that the DoF visible in the viewfinder will be quite a bit larger than recorded - because those screens were optimized for slower lenses.

 

[nickandre]

The entire body with the screens. The screens may not be sitting correctly on the camera.

Alright will do, thanks for all the help! I may shake my piggy bank a few more times and get a 42210 so that I can try AMD without the focusing aid. Wondering whether AMD is worth it or if ground glass is sufficient with the f/2 lens...

Imagine how much better my pictures will look when they're in focus

 

[nickandre]

These images are fascinating. Thanks for sharing them.

Happy to burn an evening doing something like this Plus now I know that my ol' ground glass is the closest of them, and I have an important shoot coming up with the fam over Easter.

This is how the current lenticular or prismatic "bright" screens work. A GG will show something close to the correct DoF, the image of the GG screen attached above appears slightly back focused on the screen image, that and the Fresnel lens make the rear part of the image look sharper. The current bright screens redirect the scattered light towards the eye-point, making the screen look brighter, but at the same time affecting OOF blur and DoF. Take a look at focus screens available pre-autofocus, and you'll see that they made separate screen for small aperture telephoto lenses, and microscopes, fast primes and slower zooms. The reasons are that the F-stop determines the angle that the cone of light that hits the screen, and the lenticular/prismatic/fresnel components are optimized to redirect this cone of light. The Hasselblad screens were designed for f/2.8~f/4, where it works really well. Unfortunately these screen do not handle the 2/110's wider light cone, and only uses the central ~f/2.8 part, thus showing a D0F approximately ~f/2.8~4.

If you put a wax film GG screen (ie: BOS), you will see the DoF correctly - but the image will be relatively dim.

If you take a non-pro SLR, which were sold with moderately slow zooms, and put a fast prime on it, you will see that the DoF visible in the viewfinder will be quite a bit larger than recorded - because those screens were optimized for slower lenses.

That might explain why I have an easier time with the GG screen on the f/2. If I shot with a 250mm f/5.6 on the 500cm ground glass I'd hope I can manage with a GG on the f/2 lens. I think I'll pick up a straight ground glass screen like the 42161 (?) with no focusing aid since they're cheap.

Yeah I recall this is why you can't really manual focus without the aid in DSLR land/doesn't the F5 have swappable screens for this reason? Any idea how they made the Acute Matte D version more accurate while still bright? perhaps magic...

 

[Sirius Glass]

Alright will do, thanks for all the help! I may shake my piggy bank a few more times and get a 42210 so that I can try AMD without the focusing aid. Wondering whether AMD is worth it or if ground glass is sufficient with the f/2 lens...

Imagine how much better my pictures will look when they're in focus

The prints and slides look better if the lens cap is removed before taking the photograph.

 

[nickandre]

The prints and slides look better if the lens cap is removed before taking the photograph.

Every time I come here I get an amazing photography tip

 

[nickandre]

In the interest of not keeping everyone in suspense, 3 updates:

1. I tried with ye olde 500cm ground glass and focus was dead on.
2. I chatted another YouTube 110 f/2 photographer who reports similar frustrations focusing this lens. He said he even went to such lengths as to get a dedicated focus screen made for this lens.
3. I asked David Odess about this snafu. His reply:

"The film magazines and focusing screens do not need to be adjusted for focus. It is important, however, that the camera body's length, mirror angle, ground glass height and flatness be correct. If these measurements of the camera body are correct, there should be no issue in focusing, unless the lens is out of focus, the user needs to use a different focusing screen, or the user needs to use a diopter.

Some people have a difficult time focusing correctly with the Acute Matte or Acute Matte D plain focusing screens. I would suggest that you try a different focusing screen, such as a split image or central grid (microprism)."

I'm suspicious that it's simply very difficult to focus the 110 f/2 with the AMD screens/I am not worthy. The Hasselblad manual recommends focusing the 110 on the Acute Matte which sounds hilarious given my focusing tests and the ridiculous depth of field I saw. Here's the 110 with ground glass using handy doggo as voluntary test subject; I seem to have nailed the floof focus:

And yes I dropped the film while hanging it, pay no attention.

 

[John Will]

Some people have a difficult time focusing correctly with the Acute Matte or Acute Matte D plain focusing screens.

That would be people like me. I brought an acute matte D plain screen for my 500cm some 10 years ago and could never get as accurate focus as the original screen. I tried many, many times determined to get used to it and make it work, never did! I've lost count on the number of times I swapped the screen back and forth. I eventually gave up and the original screen has remained in place to this day, As far as I'm concerned it is accuracy over brightness.

 

[nickandre]

Some people have a difficult time focusing correctly with the Acute Matte or Acute Matte D plain focusing screens.

That would be people like me. I brought an acute matte D plain screen for my 500cm some 10 years ago and could never get as accurate focus as the original screen. I tried many, many times determined to get used to it and make it work, never did! I've lost count on the number of times I swapped the screen back and forth. I eventually gave up and the original screen has remained in place to this day, As far as I'm concerned it is accuracy over brightness.

Yeah my suspicion is that I will find that the AM screen works well on f/4 and slower and the AMD works on f/2.8 and slower. I will run another test today to verify with lenses stopped down -- it would be a bummer if it was blanket reduced focusing accuracy with all lenses though...

 

[itsdoable]

.... Any idea how they made the Acute Matte D version more accurate while still bright? perhaps magic...

The Acute Matte D screens are lenticular, like all current "bright" screens used in SLRs. The Acute Matte (non-D) is a prismatic screen.

Acute Matte is a Minolta product, they came up with the first really good "bright" screen - on their 35mm cameras, they were clearly the best. It was basically full of shallow microprisms that worked down to f/8, working much like the Microprism focus aides, but with prisms so small you cannot see them. If you hold a Acute Matte screen up against a distant point of light, you'll see a neat prismatic pattern that you will not see on a lenticular screen. This is a good test to see if you have a Acute Matte - although the "D" cut-out is also good.

The problem with prismatic screens is that there exists an slight aerial image at the focus point. An Aerial image is what you see looking through a telescope or microscope - the image remains sharp over small range of focus because your eyes re-focus to compensate. When you focus on an Hasselblad Acute Matte, there is a tiny (really tiny!) range that you can focus the lens and the image remains sharp to your eye - this is you eye compensating for the aerial image. This range was too small to see on 35mm screens. The trick to focusing on these screens was to make sure the scribed lines on the screen were also in focus to your eyes, this placed the aerial image on the same plane as the lines - it's an old studio trick we learned with Hasselblad equipment. The other trick is to move your head side to side, and parallax between the aerial image and scribe marks will make them appear to move - this is how you focus on Microscopes and Telescopes with the Microscope specific screens (which only show the aerial image).

Lenticular screens came out to get around the Minolta Acute Matte patent, and at the same time improved the aerial image issue to a point where it doesn't affect focusing. They are comprised of tiny lens on the surface that re-direct the light towards the eye point. The lenses are so small that they act as scatter points much like a ground glass, and the lenses replace the function of the Fresnel.

All bright screens (lenticular or prismatic, or fresnel) are optimized to a specific cone of light, and will not show the proper DoF for lenses that have a bigger cone of light - ie: fast lenses like the 110.

Sorry for the long post - it's hard to make the explanations short and understandable....

 

[Grim Tuesday]

The problem with prismatic screens is that there exists an slight aerial image at the focus point. An Aerial image is what you see looking through a telescope or microscope - the image remains sharp over small range of focus because your eyes re-focus to compensate. When you focus on an Hasselblad Acute Matte, there is a tiny (really tiny!) range that you can focus the lens and the image remains sharp to your eye - this is you eye compensating for the aerial image. This range was too small to see on 35mm screens. The trick to focusing on these screens was to make sure the scribed lines on the screen were also in focus to your eyes, this placed the aerial image on the same plane as the lines - it's an old studio trick we learned with Hasselblad equipment. The other trick is to move your head side to side, and parallax between the aerial image and scribe marks will make them appear to move - this is how you focus on Microscopes and Telescopes with the Microscope specific screens (which only show the aerial image).

Fascinating post! Mamiya actually made focusing screens for C330 with a center spot that was un-ground and with an engraved cross, for using that aerial focusing technique.

 

[nickandre]

The Acute Matte D screens are lenticular, like all current "bright" screens used in SLRs. The Acute Matte (non-D) is a prismatic screen.

Acute Matte is a Minolta product, they came up with the first really good "bright" screen - on their 35mm cameras, they were clearly the best. It was basically full of shallow microprisms that worked down to f/8, working much like the Microprism focus aides, but with prisms so small you cannot see them. If you hold a Acute Matte screen up against a distant point of light, you'll see a neat prismatic pattern that you will not see on a lenticular screen. This is a good test to see if you have a Acute Matte - although the "D" cut-out is also good.

The problem with prismatic screens is that there exists an slight aerial image at the focus point. An Aerial image is what you see looking through a telescope or microscope - the image remains sharp over small range of focus because your eyes re-focus to compensate. When you focus on an Hasselblad Acute Matte, there is a tiny (really tiny!) range that you can focus the lens and the image remains sharp to your eye - this is you eye compensating for the aerial image. This range was too small to see on 35mm screens. The trick to focusing on these screens was to make sure the scribed lines on the screen were also in focus to your eyes, this placed the aerial image on the same plane as the lines - it's an old studio trick we learned with Hasselblad equipment. The other trick is to move your head side to side, and parallax between the aerial image and scribe marks will make them appear to move - this is how you focus on Microscopes and Telescopes with the Microscope specific screens (which only show the aerial image).

Lenticular screens came out to get around the Minolta Acute Matte patent, and at the same time improved the aerial image issue to a point where it doesn't affect focusing. They are comprised of tiny lens on the surface that re-direct the light towards the eye point. The lenses are so small that they act as scatter points much like a ground glass, and the lenses replace the function of the Fresnel.

All bright screens (lenticular or prismatic, or fresnel) are optimized to a specific cone of light, and will not show the proper DoF for lenses that have a bigger cone of light - ie: fast lenses like the 110.

Sorry for the long post - it's hard to make the explanations short and understandable....

Thanks so much! I think this may explain the problem. Although still weird that the AMD screen is yielding front focusing through the focusing aid...

 

[eli griggs]

For the very narrow focusing, try extension tubes, once you decide on which GG you will be using.

This Yourtube video is an example of what can be done, and remember, like normal photography, the longer the focal length, the wider the distance of any particular F-stop covers, so you can, so if 80mm or 150mm, can no do it, try a 180mm or larger, or even the Hasselblad zoom.

Cheers

Anyone have tips for accurately and reliably focusing a Hasselblad with some of these "very shallow depth of field" lenses for portraits? Do people have a shooting workflow they use or methods for using the focusing aid? I have the Acute Matte D focusing screen with the split prism + crackle pattern.

I have been using the focusing aid over the eyelashes and trying to minimize my recomposition (/breathing) that I do after focusing. My understanding is that with shallow enough depth of field you can introduce focus error by rotating the camera (and thus the focal plane) after focusing. I think this means, for example, that if I was going to rotate the camera down (to move a face up) after focusing that I would want to err on the near side when doing my focusing.

The percentage of in-focus shots is increasing but I'm still missing even with quite a bit of attention paid to the focusing step. Wondering if there are any tricks or this is just a "sacrifice a number of rolls of out-of-focus frames to the Hasselblad gods" and practice thing.

 

[nickandre]

FYI after refining my technique and using a regular old ground glass focusing screen (micro prism plus split prism) I am getting consistent focus. I believe that the AMD screens are not a good choice with the 110mm f/2 lens.

It is definitely a difficult lens to focus given the extraordinarily thin depth of field — you really can’t have any error without making the picture distracting, and certain angles simply don’t work.

For example although the focus here is pretty good I find the angle of the sunglasses departing the plane of focus to be a bit distracting:

Whereas here I think it worked a lot better:

Some people consider the depth of field of this lens to be a bit distracting for certain subjects at close distance but I think it works with certain compositions.

Here is an example of depth of field at minimum focus distance wide open, which I thought had a cool effect: