CFV: The Wide Angle Answer : -)

[fotografz]

Yes folks, this is the digital back that keeps on givin' ... the little back that could : -)

Crop factor of 1.5X poses the issue of wide angle capture for lovers of sweeping panoramic landscapes. If you use a 40mm and crop, you lose a lot of resolution.

Thanks to IKE, it's raining here like crazy. So I pulled out my rainy day list of stuff to try ... and did some shots with the PC Mutar & 40IF on my 203FE/CFV.

Has to be on a tripod, but for landscapes it should be anyway. Super simple to do. Use manual metering with the PC Mutar in the center shift position, focus,
adjust shift to one extreme ... shoot, set to other extreme ... shoot. Merge in PS Photomerge ... 5 to 10 seconds later there it is ... an almost 12" X 23", 200+ meg., 16 bit file with no interpolation ... with that 9 micron pixel look we all love. So a 24" X 46" print should be a no brainer since lots of people pull 24"X24" prints from this back all the time.

In a manner of speaking, the square is an advantage here since when they're merged it adds up to a nice ratio using just 2 shots.

Crap light, especially indoors ... but I just wanted to see how it worked ... so I tried an outdoor pano from inside my garage, and another closer pano of Shnuffy hunkered down on the couch.

Hmmm, how much $ is that new Leaf Panoramic format camera?

 

[vandevantersh]

Very interesting...It is also raining "cats and dogs" (Katzen und Hunde) here along with tornado alerts. Shnuffy is very cute, I especially like the one with him/her and the very large dog.*g*

Steve

 

[bensonga]

Hi Marc,

I didn't know anything about the PC Mutar until you posted this....so I did a quick google and found some info about it (including one available on Ebay for $1,499).

Re the crop factor....do you have to combine the CFV's 1.5 crop factor with the PC Mutar's crop factor of 1.4 to figure out how much the combined lens factor before any stitching etc?

Is there any benefit to using the PC Mutar instead of something like the Really Right Stuff Panoramic Panning Rails/Clamps to shift left and right?

I haven't done any panoramic stitching etc yet.

Gary Benson

 

[michaelhcothran]

Your concept was heavily discussed at one time on the Naturescapes website - with someone doing the same thing with a Canon TS lens.

Bensonga - I applied this concept to my own 40mm lens using a 28" rail from Really Right Stuff. Long story short, it did not work at all on landscape images. Here's a link to what I bought, in case you're interested in seeing the rail -
http://reallyrightstuff.com/rrs/Itemdesc.asp?ic=CB-28&eq=&Tp=

There is obviously something technically different about shifting a lens a few millimeters compared to "sliding" it across a 28" rail. Hmmm.....
However, I have had success with stitching as many as 4 images with all my CF lenses, including the 40 using CS3 and Photomerge. I've had success with mosaics (multiple rows) with my 35 DSLR - 4 rows of 4 images, but haven't tried it yet with the CFV. While I try to mount the lenses as close as possible to their nodal points, it really isn't that critical, as Photomerge does an excellent job of aligning for you if your pans are a little off. Do try to overlap at least 25%, and more is better.

 

[vandevantersh]

Michael, do you remember reading an article, (Uwe Steinmuller?) were a camera with shift lens was placed on a rail and the lens was shifted in one direction and the camera opposite? That was supposed to be "the way to do it". I didn't understand it then and now I can't find it to re-read.

Steve

 

[michaelhcothran]

Here are two mosaic panos I spoke of from the last posting. These were done with a Fuji S2 Pro digital (6 mpix). Ok, they advertise 12, but that's in-camera interpolation from a 6 mpix sensor.
Each image is made of 16 images - 4 rows of 4 images, and stitched in CS3 with Photomerge. I print at home with an Epson 7600, so 24" prints are my standard. These print @ 24x36 with incredible detail.
BTW - my CFV images print 24x24 @ 170 ppi uncropped, also with incredible detail.

And may the Hasselblad gods have mercy on me for posting non-Hasselblad images here, but I wanted to show what can be done with Photomerge.

1st image - Buzzard's Roost - Fall Creek Falls State Park, Tennessee
2nd image - Middle Prong of the Little River, Tremont area, Great Smoky Mountains National Park, Tennessee

 

[michaelhcothran]

Michael, do you remember reading an article, (Uwe Steinmuller?) were a camera with shift lens was placed on a rail and the lens was shifted in one direction and the camera opposite? That was supposed to be "the way to do it". I didn't understand it then and now I can't find it to re-read.

Steve

I don't, but I don't think that shifting the camera opposite will help. Technically, the lens can only shift so far no matter how you do it. So once you shift the lens its maximum (maybe 10-15mm), shifting the camera back in the opposite direction is going to take the lens right back with it.
BTW - With the rail, you can get very accurate pano results as long as the subject is only a few feet away, and it works perfectly for macro panos. It's just that for infinity subjects, 28" is nothing.
Your theory would work with a view camera, as it has an adjustable bellows between the front and rear movements. Here you could adjust the front standard to max, and still be able to adjust the rear standard in the opposite direction (assuming, of course, that the camera being used had rear shift capabilities).

 

[vandevantersh]

" It's just that for infinity subjects, 28" is nothing."

Ah..Ha.. vs rotation for pano.

Steve

 

[fotografz]

I'm not a tecno photo-geek, but rough calculations in my head tells me that you improve the FOV a little, however what you really gain is resolution in a panoramic format.

The 1.5X crop factor of the CFV is a fixed fact of life for any lens. The Mutar adds an additional 1.4X factor for lenses from 40mm to 80mm.

(For reference using a film back: the 40mm produces a FOV of 88º; a 50mm = 76º; a 60mm = 66º; and a 80mm = 52º)

When using a CFV back with its 1.5X crop factor, a 40mm produces a FOV of a 60mm = 66º FOV

Add an unshifted PC Mutar with its additional 1.4X factor, and that 40mm produces the FOV of a 84mm = approx. 55º FOV.

However, when you shift to the extremes either way with the PC Mutar and merge, it "visually" appears to me that you add about 75% FOV (the other 25% is overlap.)

If that is anywhere near correct, it then produces about a 75º FOV ... roughly the same as 50mm when using film ... some gain in FOV over the 40mm alone when using a the CFV back.

Perhaps more importantly, the PC Mutar Panoramic file is now considerably higher resolution than if you shot the 40mm alone with the CFV and cropped the top and bottom to a panoramic 1 to 2 ratio.

Uninterpolated Tiff files from the CFV are 50/100 meg ... the stitched files are 87.5/175 meg. and the 16meg (4080 X 4080) sensor is now the equivalent of a 28 meg panoramic sensor = 4080 X 7140 pixel files (17" X 30" @ 240 PPI.) Also the 36.7mm X 36.7mm CFV sensor becomes the equivlant of a 36.7mm X 64.2mm sensor ... which doesn't exist ( the new Leaf panoramic sensor is 36mm X 54mm)

The fact that we're working with a square sensor now becomes an advantage because the resulting panoramic print ratio is a highly desireable one ... while preserving the 9X9 micron look ... something no other larger digital back offers at this time.

If this info gets out to everyone with a CFV, bet the price of the PC Mutars will skyrocket : -)

 

[polypal]

Thanks for the explanation Marc.

I have never seen so many figures in a post from you before!

Paul

 

[fotografz]

Thanks for the explanation Marc.

I have never seen so many figures in a post from you before!

Paul

Probably all wrong Paul, and some engineer will rip me apart ... LOL !

But I do know what I see.

I just got back from trying some more Panoramics around my neighboorhood ... can't do a real shoot since 50 mph winds and driving rain is gonna be here in a few hours. Plus, my son lives in Houston and I'm waiting word on how they did against IKE.

I'll post a few if I get a chance. This is fun to learn.

 

[polypal]

But I do know what I see.

....... This is fun to learn.

Nothing wrong with your eye sight

Once again you showed the possibilities of the largest MF camera system in existence.
Not that all parts are still available from new but the s/h market will certainly
have a few 1.4 shift converters for sale.
Prices will go up for those I am sure.

Paul

 

[michaelhcothran]

Here's a 3-shot CFV pano using the 100 CF lens, and stitched in CS3 Photomerge. I do believe I posted a single shot of this image in another thread, but not the pano version.

As Marc states, these are "fun" to do, and the great advantage one gets from stitching is the increase in file size, leading directly to MORE detail. However, one can go overboard, as the files become enormous. I often find myself working with files in excess of 2 GB's. Unless you are making prints better measured in "feet" than in "inches," there IS a point at which all this becomes moot.

I do have to respectfully disagree with the prediction of the PC Mutars taking off. It is definitely useful in easily creating perfectly aligned panos. This is the big advantage of any shift lens. No argument there at all. But being a tele-converter, in combination with the CFV, it defeats its use for wide angle coverage, in my opinion. You could get the same result as the Mutar/40mm combo simply by mounting your 60mm lens with no Mutar. The disadvantage of a shift lens is that it limits the amount of panning that you can do - you can only "pan" as far as the lens will shift. While I would definitely own & use a shift lens, if it were available, the PC Mutar is NOT the answer, in my opinion. But I agree it would be fun to play with - IF...I already owned one.

Photomerge does an excellent job of aligning, so if your pans are slightly off, it will not only align them, but it will also blend them. It is amazing. However, one shortcoming of Photomerge to date is its lack of manual anchor points. Perhaps a later version will include these.

 

[polypal]

Michael,

I think you have a point about the use of a shift lens or the 1.4 shift converter.

Regardless their use to create panos the shift converter will stay an expensive item and might go up in price.
There are not that many of those to begin with.
Production ceased several years ago.

Paul

 

[jotloob]

Has to be on a tripod, but for landscapes it should be anyway. Super simple to do. Use manual metering with the PC Mutar in the center shift position, focus,
adjust shift to one extreme ... shoot, set to other extreme ... shoot. Merge in PS Photomerge ... 5 to 10 seconds later there it is ... an almost 12" X 23", 200+ meg., 16 bit file with no interpolation ... with that 9 micron pixel look we all love. So a 24" X 46" print should be a no brainer since lots of people pull 24"X24" prints from this back all the time.

Marc

Thank you for showing your very interesting pano experiments .

I have looked up the latest HASSELBLAD catalogue showing the
CZ PC-MUTAR 1,4 SHIFT CONVERTER.
The shift possibility is +-16 mm .
Do I understand you correct , that you do two exposures , one at the -16mm shift point and one at the +16mm shift point .
No exposure in the middle position ? ? ?

I have just checked my ARCA SWISS ROTASLIDE adapter .
There I have 3 possibilities for different shifts . The one is a total of 34mm . That seems to be the one for a square sensor size of 37x37mm .

I will try the "pano shift" technique , as soon as we have a better weather here . It is raining since two days and I have not seen the sun since 3 days .

I am very much looking forward for my first results .
I have a very interesting historical building in mind and will use the
RODENSTOCK APO GRANDAGON 4,5/45mm lens . That gives a 67,5mm lens at crop factor 1,5 .

BTW , Marc , you should give me your mailing address for sending the calendar . You can PM that .

Regards Jürgen

 

[fotografz]

Here's a 3-shot CFV pano using the 100 CF lens, and stitched in CS3 Photomerge. I do believe I posted a single shot of this image in another thread, but not the pano version.

As Marc states, these are "fun" to do, and the great advantage one gets from stitching is the increase in file size, leading directly to MORE detail. However, one can go overboard, as the files become enormous. I often find myself working with files in excess of 2 GB's. Unless you are making prints better measured in "feet" than in "inches," there IS a point at which all this becomes moot.

I do have to respectfully disagree with the prediction of the PC Mutars taking off. It is definitely useful in easily creating perfectly aligned panos. This is the big advantage of any shift lens. No argument there at all. But being a tele-converter, in combination with the CFV, it defeats its use for wide angle coverage, in my opinion. You could get the same result as the Mutar/40mm combo simply by mounting your 60mm lens with no Mutar. The disadvantage of a shift lens is that it limits the amount of panning that you can do - you can only "pan" as far as the lens will shift. While I would definitely own & use a shift lens, if it were available, the PC Mutar is NOT the answer, in my opinion. But I agree it would be fun to play with - IF...I already owned one.

Photomerge does an excellent job of aligning, so if your pans are slightly off, it will not only align them, but it will also blend them. It is amazing. However, one shortcoming of Photomerge to date is its lack of manual anchor points. Perhaps a later version will include these.

So, I take it that you do not have a PC Mutar?

From what I can figure using the CFV back, the combination of the 40mm & PC Mutar shifted both ways for 2 shots merged in PS produces a wider effective FOV than a 60mm with no mutar ...

The 40mm by itself with the 1.5X of the CFV = 66º FOV ... and a CFV & 60mm produces approx. a 46º FOV. As explained above, I think the CFV and PC Mutar shifted and merged produces an approx. 75º FOV Pano ... which is a wider FOV than with any single lens you can use alone with the CFV ... and only exceeded by the 40mm using film.

So it seems that if a wider angle FOV is what you want, the PC Mutar IS a simple answer. Not the only one, but an elegant, easy to use one ... and it does provide Perspective control for vertical shots of buildings.

Plus the merged tiff file is almost twice the resolution. If the 60mm square shot were cropped to pano format, the resolution difference would be even greater.

Of course, if one wants a much wider width to height ratio then other techniques would have to be employed.

The PC Mutar is also very, very fast to use.

Yes Jurgen, just two shots for perfect merges. There is already an overlap. At first I was using three shots, but found it unnecessary.

Had only a few hours reprieve from the relentless storms generated by IKE, but managed to get out in the neighborhood to shoot a few Panos. No great shots, just experiments. The Gazebo was shot fairly close to the subject and retains a W/A look for a feeling of depth.

 

[michaelhcothran]

Quote:
Originally Posted by fotografz
So, I take it that you do not have a PC Mutar?

From what I can figure using the CFV back, the combination of the 40mm & PC Mutar shifted both ways for 2 shots merged in PS produces a wider effective FOV than a 60mm with no mutar ...


No I don't have a PC Mutar. But my point here is that I would not buy a PC Mutar for the sake of doing panos, as it's just not necessary.

My other thought is that a 40/Mutar combo panning 2 shots should be about the same as a 60mm lens alone ALSO panning 2 shots. In which case, file sizes should also be about the same. Using the 40/Mutar yields an 84mm lens, using the 60 yields a 90mm. All with a CFV of course.


edited to restore the quote.
Paul

 

[fotografz]

Quote:
Originally Posted by fotografz
So, I take it that you do not have a PC Mutar?

From what I can figure using the CFV back, the combination of the 40mm & PC Mutar shifted both ways for 2 shots merged in PS produces a wider effective FOV than a 60mm with no mutar ...


No I don't have a PC Mutar. But my point here is that I would not buy a PC Mutar for the sake of doing panos, as it's just not necessary.

My other thought is that a 40/Mutar combo panning 2 shots should be about the same as a 60mm lens alone ALSO panning 2 shots. In which case, file sizes should also be about the same. Using the 40/Mutar yields an 84mm lens, using the 60 yields a 90mm. All with a CFV of course.


edited to restore the quote.
Paul

I think I understand the point.

So the camera is mounted on a rail to shift it side-to-side a predetermined amount. So it's not really "panning"

I did an experiment in the studio ... shot with a H3D-39-II back on a Rollei Xact using a 45mm APO Digital lens (no shifts) ... and then the 203FE/CFV & 40IF-PC Mutar. The merged Mutar shots produced a wider FOV than the 45 with the H3D-II near 645 sized sensor (1,1X verses 1.5X) ... and the file was just as good or better. These were both done pretty close up and there was just enough room to get the camera in there. The CFV one is the narrower photo.

At any rate, no matter how it's accomplished, nice to discover that one can equal a back that costs 3X+ more by using these merging techniques. I could actually see using a CFV in this manner for serious commercial shoots and be able to equal the resolution of a far more expensive digital back ... and do it with those big beautiful 9X9 micron pixels ...

 

[Swissblad]

Hi Marc,
An interesting approach, but if I do understand it correctly, you won't be able to generate that wide-angle feeling ie objects become small in the background, exaggerated foreground (which is quite special and I like a lot).
Correct me if I'm wrong.
Cheers
Sinuhe