Hasselblad Flexbody Tilting

DonFilm · Sep 8, 2018

I am having troubles in using flexbody tilting function. I did try three(3) methods in the controlled environment at home to get sharp images from foreground to the background. Let me first introduce the methods I experimented below:
[Method 1 - Google search]
Step 1: Set the aperture at f2.8. This is to ensure a pin-point focusing with lens wide open.
Step 2: Focus on the farthest subject with focus ring.
Step 3: Adjust tilt knob until the closest subject looks sharp.
Step 4: Repeat from Step 2 and 3 until I am satisfied.
Step 5: Re-set the aperture at f11 expecting the best performance from the lens and deeper DoF.
[Method 2 - Google search]
Almost the same procedure as Method 1 except focusing on the foreground and tilting for the background.
[Method 3 - Hasselblad Manual by Ernst Wildi]
Start by focusing the lens at a point approximately one-third beyond the closest and two--thirds in front of the farthest subject distance. For example, focus at 14 feet (4.3m) when the closest subject is 6 feet (1.9m) and the farthest is 30 feet (9.1m). Tilt the image plane in one direction and check whether the sharpness range increases. If not, tilt the plane in the other direction. Check the sharpness at the top and bottom and see whether both become critically sharp at some point. If they do not, change the focus setting on the lens. You will quickly find a point where you have sharpness over the entire plane.

Unfortunately, none of the methods gave me a satisfactory result.
Though Method 3 seems to me the relatively easily achievable method compared to others. But it will be useless in the field because I wouldn't have any reliable way to measure the distance such as one-third beyond the closest and two--thirds in front of the farthest subject distance. In addition, I would get only ACCEPTABLY sharp images instead of tack sharp images. Either Method 1 or Method 2 guarantees tack sharp images at least at one point, foreground or background. However, I can hardly achieve one good plane of focus by tilting with Method 1 and 2. FYI, I used PM5 prism viewfinder and Flexbody correction screens.

During the experimentation, I have a fundamental question whether I could move the flexbody to let split-image focusing screen located onto the foreground subject in case of Method 1 (or background in case of Method 2) to check the sharpness change during the tilt adjustment. Or should I maintain the pre-determined composition and check the sharpness through the off-center prism viewfinder?

Thanks in advance for your kind guidance,
DonFilm

John Koehrer · Sep 8, 2018

I'm not sure why you need the flex body for "general" photography. Anyway. my use in the past
has been focus using method #3, obviously the same as LF.
The flex would normally be used to correct for keystoning or to increase depth of focus in close work and a little
bit of adjustment goes a long way.

I'm sure you'll get more information from those with more LF experience soon.

DonFilm · Sep 8, 2018

John Koehrer said:
I'm not sure why you need the flex body for "general" photography. Anyway. my use in the past
has been focus using method #3, obviously the same as LF.
The flex would normally be used to correct for keystoning or to increase depth of focus in close work and a little
bit of adjustment goes a long way.

I'm sure you'll get more information from those with more LF experience soon.

Hi John,
Thanks for your reply. I'd like to use Flexbody to increase depth of field in landscape photography. I may seldom use it for architecture photography. Maybe I could use it for closeup photography when I add the macro lens like 120mm Makro to my lens lineup some day.
As far as I know, either method #1 or #2 has been being used by large format photographers depending on the types of their LF camera, i.e. base tilt or axis tilt. Maybe I am wrong.

btaylor · Sep 8, 2018

It strikes me that the issue you seem to be having is confirming focus accurately. In LF that is handled with a loupe on the ground glass. So how about trying a plain gg screen with a loupe? Ditch the prism and try it.
Another factor to think about— f22 is the go to aperture in LF, are you using something larger?

Patrick Robert James · Sep 9, 2018

I've always used Schleimfluggies Easy Peasy Lemon Squeezy method. Imagine the plane of focus you want, intersect that with the plane of the film, then match the plane of the lens to that point. Adjust the aperture for depth of field of course. For a near/far landscape, intersect everything at the ground under your tripod. It gets more tricky if you want trees and such to be in focus. Pick the two most important elements in that case.

You'll need more tilt for longer lenses than for shorter lenses.

Hope that helps you.

DonFilm · Sep 9, 2018

btaylor said:
It strikes me that the issue you seem to be having is confirming focus accurately. In LF that is handled with a loupe on the ground glass. So how about trying a plain gg screen with a loupe? Ditch the prism and try it.
Another factor to think about— f22 is the go to aperture in LF, are you using something larger?

I do think that I understand correctly what and how to do for maximum sharpness from near to far in theory. For your info, the Hasselblad Flexbody has rear standard tilt & shift function only. The front standard doesn't move at all. The manual says not to attempt to use loupe on the focusing screen. In fact, it's not easy for me to confirm through the Hasselblad prism viewfinder whether the near point becomes sharp while adjusting tilt knob. I know the LF ground glass is huge compared to Hasselblad' 55x55 mm viewfinder. Regarding the aperture, I'd rather not to go beyond f13 due to diffraction effect. Thanks!

DonFilm · Sep 9, 2018

Patrick Robert James said:
I've always used Schleimfluggies Easy Peasy Lemon Squeezy method. Imagine the plane of focus you want, intersect that with the plane of the film, then match the plane of the lens to that point. Adjust the aperture for depth of field of course. For a near/far landscape, intersect everything at the ground under your tripod. It gets more tricky if you want trees and such to be in focus. Pick the two most important elements in that case.

You'll need more tilt for longer lenses than for shorter lenses.

Hope that helps you.

The books and articles on internet all said the same things as what you wrote here. I should be able to make those knowledge in real life freely. Thanks a lot!

alentine · Sep 9, 2018

Don, I think you are tilting faster and greater than what would be required, or you may be locating farthest/near points more extreme at the edges of the ground glass. Other possibility is your prism does not show clear image(defect) or has less than enough magnifying power.
Tilt in this post, means only film plane backward tilt or sharpness compensation as said by LF photographers, since no front/lens plane forward tilt in flexbody.
Always remember, the depth of field is no longer of parallel zone, with tilt. The parallel zone becomes a wedge, like the head of triangle just under your camera at the foreground, when you tilt. That require you to be cautious when you start to tilt. At the farthest point, DOF zone is wide like the base of triangle, and you have more control, but not easier due to diminishing sizes on the ground glass at the farthest distances.
In case of landscape photography, with any wide angle lens, you just need 1°-2° or about, only.
Methods1&2, looks correct enough.
Your prism finder will work, but I do not know if RMfx or HM2 finders will give bigger image and better focussing?
I think the normal accessory with flexbody, is RMfx.
Think of this method:
1. Zero your flexbody. Zero tilt, shift and extension. Tighten all knobs.
2. Frame your scene like with a fixed camera.
3. Focus your lens on farthest point. May be not less than one third from the border of ground glass.
4. Make sure your flexbody is zeroed, scene is framed no more adjustments, tripod is stable.
5. Put a contrasty subject(or select) at a distance in the foreground that you need it to be sharp.
At this step, you have to be clever. True life physics has possible and impossible. Not similar to the assumptions in PS on computer.
The contrasty subject is used to focus on, while tilting. It should be a little inside the border, not near or at the border of your ground glass/GG. May be one third inside.
6. Now, tilt very carefully(after loosening tilt knob), while watching your selected object in the foreground. With the first hint of its image being improved on the GG, STOP tilting, then from that point start very carefully fine tuning your tilt/focus(fore/back, by tilting) on the foreground subject.
Once you reach optimal tilt/focus on the foreground, go back to the farthest point to check its focus, plus all image sharpness on the GG.
7. Fine tune farthest focus by reverse tilting(just a little) or by refocusing your lens. I think wide angle lenses will provide its max performance at infinity.
8. Tight tilting knob screw.
9. Start the sequence of taking photo.

DonFilm · Sep 9, 2018

alentine said:
Don, I think you are tilting faster and greater than what would be required, or you may be locating farthest/near points more extreme at the edges of the ground glass. Other possibility is your prism does not show clear image(defect) or has less than enough magnifying power.
Tilt in this post, means only film plane backward tilt or sharpness compensation as said by LF photographers, since no front/lens plane forward tilt in flexbody.
Always remember, the depth of field is no longer of parallel zone, with tilt. The parallel zone becomes a wedge, like the head of triangle just under your camera at the foreground, when you tilt. That require you to be cautious when you start to tilt. At the farthest point, DOF zone is wide like the base of triangle, and you have more control, but not easier due to diminishing sizes on the ground glass at the farthest distances.
In case of landscape photography, with any wide angle lens, you just need 1°-2° or about, only.
Methods1&2, looks correct enough.
Your prism finder will work, but I do not know if RMfx or HM2 finders will give bigger image and better focussing?
I think the normal accessory with flexbody, is RMfx.
Think of this method:
1. Zero your flexbody. Zero tilt, shift and extension. Tighten all knobs.
2. Frame your scene like with a fixed camera.
3. Focus your lens on farthest point. May be not less than one third from the border of ground glass.
4. Make sure your flexbody is zeroed, scene is framed no more adjustments, tripod is stable.
5. Put a contrasty subject(or select) at a distance in the foreground that you need it to be sharp.
At this step, you have to be clever. True life physics has possible and impossible. Not similar to the assumptions in PS on computer.
The contrasty subject is used to focus on, while tilting. It should be a little inside the border, not near or at the border of your ground glass/GG. May be one third inside.
6. Now, tilt very carefully(after loosening tilt knob), while watching your selected object in the foreground. With the first hint of its image being improved on the GG, STOP tilting, then from that point start very carefully fine tuning your tilt/focus(fore/back, by tilting) on the foreground subject.
Once you reach optimal tilt/focus on the foreground, go back to the farthest point to check its focus, plus all image sharpness on the GG.
7. Fine tune farthest focus by reverse tilting(just a little) or by refocusing your lens. I think wide angle lenses will provide its max performance at infinity.
8. Tight tilting knob screw.
9. Start the sequence of taking photo.

Hi alentine,
I think I was not cautious enough when adjusting the tilt control knob. During my experimentation, I used a 80mm Planar and the tilt knob was mostly somewhere around 10 degree position. I guess this seemed to be partly caused by insufficient magnification of the PM5 prism viewfinder. Maybe PM5 is OK, and I need more exercise with PM5 together with Flexbody. I had no problems with PM5 attached to 503CX body. Thank you very much for your deliberate reply with detailed guidance.

Don

Sirius Glass · Dec 11, 2021

I am thinking about getting the FlexBody and these posts have been very helpful to understand the use and feel of the FlexBody. Thank you.

Arthurwg · Dec 11, 2021

Steve Simons says in his large format book that only small tilts and shifts are required to get adequate results.

Sirius Glass · Dec 11, 2021

Arthurwg said:
Steve Simons says in his large format book that only small tilts and shifts are required to get adequate results.

In my one time with the Speed Graphic and the 28mm Nikon PC lens, it can already see that with shifts.

Ai Print · Dec 11, 2021

I use a chimney finder to compose and a small 10x peak loupe with some felt on the base to confirm if I need to. I turn it around to check the corners / far sides, not touching the screen.

I do shoot 4x5 and 8x10 so I am very familiar with movements, can get there very fast.

Now….I know this is going to sound weird but I find I am faster and most accurate when I de-focus the scene and then bring entire image into similar areas of de-focus. I think it is much less taxing on my eyes to just feel my way through those relationships on the ground glass / focusing screen and when I focus the image, bang! It is usually tack.

Of course if you have things like rocks or trees disrupting the linearity of the plane, then you have to asses how to fudge it and if to stop down a bit more.

I have no issues using tilt to leverage a sharper overall image on the Flexbody using the methods above.

Sirius Glass · Dec 11, 2021

When I use the SWC and the adapter to look through the lens the chimney finder works better than the PME. I would suspect the same with the FlexBody.

Philippe-Georges · Dec 12, 2021

When "tilting" to increase the depth of filed the Scheimpflug way, with the Flexbody, it is better to keep the back standard (the image side) vertically by swinging the whole set up forward so that the subject side (lens side) is tilted, not the back.
See this photo as an illustration:

eli griggs · Dec 14, 2021

I am going to look for a chimney finder with Doppler adjustments for my Flexbody and 500 cm.

I have the original 500 cm finder in that camera, but between that and the Flexbody, a chimney finder makes the most sense.

My loop is an old Ednalite (?) with a metal base but I can no get a solid focus with it in too many situations, with either camera.

I feel that I can get a sharp focus, in good light, with the WLF, old cm model, by simply placing my eye, in contact with the top, open finder, in the 500 cm, but with the Flexbody, that's no quite the same feeling of assured confidence, that I get with that basic Hasselblad camera, thus, the need for a chimney finder.

Cheers, Keep Warm and Godspeed to all!

Philippe-Georges · Dec 14, 2021

eli griggs said:
I am going to look for a chimney finder with Doppler adjustments for my Flexbody and 500 cm.

I have the original 500 cm finder in that camera, but between that and the Flexbody, a chimney finder makes the most sense.

My loop is an old Ednalite (?) with a metal base but I can no get a solid focus with it in too many situations, with either camera.

I feel that I can get a sharp focus, in good light, with the WLF, old cm model, by simply placing my eye, in contact with the top, open finder, in the 500 cm, but with the Flexbody, that's no quite the same feeling of assured confidence, that I get with that basic Hasselblad camera, thus, the need for a chimney finder.

Cheers, Keep Warm and Godspeed to all!

For some good used Hasselblad accessories, you might look at kameratori.fi / kamerastore.com, amongst others...

BTW, I would be so free to advise the 45° reflex prism finder, which I use now.

eli griggs · Dec 17, 2021

Cheers!

I do have 45° finders, the NC and something newer, no meter, but unless I hand hold the camera and pre-focus it by standing up, where I can get a good eye focusing position, then reset it back on the tripod, chances are I'll no get it sharp enough.

The WLF allows me to remove my glasses to focus sharply, very near vision, but the 45° prisms are a different story and, no joy.

The adjustable chimney finder should be a big step up for my ability to focus sharply, or so I hope.

Hasselblad Flexbody Tilting

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