Technical Camera Images

[jng]

Well, Peter and Dan gave me the nudge I needed. Been almost a year since I posted an image to this thread, which is nothing compared to their hiatus.

I had the joy of photographing in the Eastern Sierra with John and others this fall. He showed some wonderful images in The Big Thread. Here is one from the base of Tioga Pass. We unapologetically stole the scene from a woman who was already pulled over making some photographs. Not quite true; we asked her permission to saunter up next to her and she was gracious. We then spent over an hour scooching our tripods left/right long after she left, waiting for breaks in the rising wind and fading light.

SK 100, Alpa 12+, IQ4150. A few mm back rise

Dave

Fabulous, Dave! I think this is my favorite image from the entire week!

John

 

[Pemihan]

Fabulous, Dave! I think this is my favorite image from the entire week!

John

Glad to be of help Dave!
Fabulous colors!

 

[dchew]

That's some fine scooching Dave!

Thank you, Rob. Since this thread is all about technical cameras, it is worth pointing out that I think this is an image that would be quite difficult, if not impossible, to make without one.

The road is a 4-6 meters above the ground shown in the photo. Obviously pointing the camera down would change the look entirely. Transforming/warping in post would be difficult since there are few plumb trees for reference, and getting the framing correct after a warp would be more luck than I possess. That leaves using a wide lens and cropping later. Again, difficult to frame as accurately, at least for me. Using rise/fall gives creative feedback on the fly.
Dave

 

[rdeloe]

Thank you, Rob. Since this thread is all about technical cameras, it is worth pointing out that I think this is an image that would be quite difficult, if not impossible, to make without one.

The road is a 4-6 meters above the ground shown in the photo. Obviously pointing the camera down would change the look entirely. Transforming/warping in post would be difficult since there are few plumb trees for reference, and getting the framing correct after a warp would be more luck than I possess. That leaves using a wide lens and cropping later. Again, difficult to frame as accurately, at least for me. Using rise/fall gives creative feedback on the fly.
Dave

That all sounds very familiar, Dave. Those "behind the scenes" details are what those of us who work with technical cameras take for granted. However, they're simply not on the radar for people who don't.

There's lots of help and resources out there for the "how" of camera movements. What I see a lot less of is the "why?" or the "so what?" I took a stab at this a couple years ago for tilt, in response to the enthusiasm for tilt that cropped up on the DPReview medium format forum when the GF 30mm tilt-shift was released. People could wrap their heads around the "so what" of shift/rise/fall, but tilt/swing just staggered most folks. I'm not sure if it made a difference, but I took a "problem solving" approach in this piece: https://www.robdeloephotography.com/Pages/Is-tilt-still-relevant

 

[accwai]

[...] We then spent over an hour scooching our tripods left/right long after she left, waiting for breaks in the rising wind and fading light.

Looks almost like something from Christopher Burkett... Fabulous!

[...] SK 100, Alpa 12+, IQ4150. A few mm back rise

The road is a 4-6 meters above the ground shown in the photo. [...]

A few mm back rise to counter 4-6m view point elevation? How far away was the subject?

 

[dchew]

A few mm back rise to counter 4-6m view point elevation? How far away was the subject?

So... "a few" is a clue that I don't remember! It is a 100mm lens on a 54x40 sensor. The closest tree on the left is maybe 8m and the base is cut off. Focus point is the live aspen trunk to the right of that closest tree; that base is in the frame. I plugged a few numbers into the PhotoPills app and come up with somewhere around 10mm; more than a few. But I'm really guessing on the distances!

Dave

 

[danlindberg]

Golden Reflection. Brantevik - Sweden.

 

[drevil]

Golden Reflection. Brantevik - Sweden.

View attachment 225091

love the image, but please remove the dust spot

 

[danlindberg]

love the image, but please remove the dust spot

Done! Missed it

 

[rdeloe]

I didn't intend for this image to be one I kept. I needed a distant line of trees roughly parallel to the sensor to check the setup of a lens, and to test whether or not adjustments to the shift mechanism I made on my camera were good. I was also curious how the grease I used performed at -10 C.

The plan was to merge the 15mm shifted frames, inspect, and toss the result. However, I ended up spending a solid hour working on it.

 

[miriquidi]

I have a question to the users of technical cameras: I use a half-self-made one connecting Nikon F glass to digital backs with FourThirds sensor. But when taking architecture like shots I still get minor plunging lines that need correction within Capture One. Right now I'm mostly shooting handheld with a bubble level on the back.
Is there some special technique that helps to absolutely level the camera to avoid this issue?

 

[dchew]

I have a question to the users of technical cameras: I use a half-self-made one connecting Nikon F glass to digital backs with FourThirds sensor. But when taking architecture like shots I still get minor plunging lines that need correction within Capture One. Right now I'm mostly shooting handheld with a bubble level on the back.
Is there some special technique that helps to absolutely level the camera to avoid this issue?

It's a really good question. When. I use the A/S cube, I have four sets of levels at my disposal:
Tripod
Cube
Alpa STC / Alpa 12+
Digital back

None of them agree! I also have a very accurate bubble level from Starrett that I've used to confirm which are the most accurate. The Alpa 12+ is the most accurate, followed by the Cube levels. In the Cube's defense, they are mounted on the structure of the cube, not the clamp. So the clamp and camera mounting add some tolerance.

The best test is to find a reference you trust. Could be a building or in my case a very accurate level. Then find out how that bubble level you use is off. Write it down and keep it with you so you can reference your reference.

Of course, that's only half the battle. You need to figure out how to get the camera position square to the subject, at least when that is important. For that, I just do the best I can using the subject and the frame lines in live view. You can obviously tether when it is critical. I assume you are using some sort of geared tripod head with a leveling base. That allows you to level the head and use the gears for fine adjustment. That saves many minutes of frustration.

Dave

 

[rdeloe]

I have a question to the users of technical cameras: I use a half-self-made one connecting Nikon F glass to digital backs with FourThirds sensor. But when taking architecture like shots I still get minor plunging lines that need correction within Capture One. Right now I'm mostly shooting handheld with a bubble level on the back.
Is there some special technique that helps to absolutely level the camera to avoid this issue?

My answer mirrors Dave's. I have two levels on the Cube and two on my F-Universalis, and they don't agree with each other or with my Stabila level. The level in my camera also has its own opinion, and none of the other levels agree with it.

The best I'm able to do is levelish and squareish. Then I fix it in post.

 

[mristuccia]

It's a really good question. When. I use the A/S cube, I have four sets of levels at my disposal:
Tripod
Cube
Alpa STC / Alpa 12+
Digital back

None of them agree! I also have a very accurate bubble level from Starrett that I've used to confirm which are the most accurate. The Alpa 12+ is the most accurate, followed by the Cube levels. In the Cube's defense, they are mounted on the structure of the cube, not the clamp. So the clamp and camera mounting add some tolerance.

The best test is to find a reference you trust. Could be a building or in my case a very accurate level. Then find out how that bubble level you use is off. Write it down and keep it with you so you can reference your reference.

Of course, that's only half the battle. You need to figure out how to get the camera position square to the subject, at least when that is important. For that, I just do the best I can using the subject and the frame lines in live view. You can obviously tether when it is critical. I assume you are using some sort of geared tripod head with a leveling base. That allows you to level the head and use the gears for fine adjustment. That saves many minutes of frustration.

Dave

Hay Dave,

I'd like to thank you for the time you spent in collecting all SK lens data in your site. I consult it frequently.
I'm trying to find the MTF data of the SK Apo-Digitar 47XL. I don't think it corresponds to the "Digitar 5.6/47" you have on your site... Any MTF source for the apo-digitar?

 

[dchew]

Hay Dave,

I'd like to thank you for the time you spent in collecting all SK lens data in your site. I consult it frequently.
I'm trying to find the MTF data of the SK Apo-Digitar 47XL. I don't think it corresponds to the "Digitar 5.6/47" you have on your site... Any MTF source for the apo-digitar?

You are very welcome. I'm hoping the new Alpa site will put up some of this. They have a location for it with links, but the links are not yet active. They used to have all this info on their older-old website.

I always thought the sk apo-digitar 47xl WAS the same as the digitar 5.6/47. I am pretty sure they did not make a new version of that lens, they just renamed it. I could be wrong...

Dave

 

[rdeloe]

You are very welcome. I'm hoping the new Alpa site will put up some of this. They have a location for it with links, but the links are not yet active. They used to have all this info on their older-old website.

I always thought the sk apo-digitar 47xl WAS the same as the digitar 5.6/47. I am pretty sure they did not make a new version of that lens, they just renamed it. I could be wrong...

Dave

I have three different PDF data sheets for the 47, including the Alpa one for the "Helevetar". In all three, the lens parameters are exactly the same. Interestingly, in none of these data sheets is it called XL. Nonetheless, I have heard the claim that the XL version is different.

This link is to the online version on S-K's site from a 2005 crawl by the Internet Archive. The data are the same as the PDF sheets. https://web.archive.org/web/2002080.../photography/digital_photography/47/page1.php

I'm curious if anyone has an "XL" data sheet that has lens characteristics that are different from the PDFs I have (one from Dave's site) and this web version.

 

[mristuccia]

You are very welcome. I'm hoping the new Alpa site will put up some of this. They have a location for it with links, but the links are not yet active. They used to have all this info on their older-old website.

I always thought the sk apo-digitar 47xl WAS the same as the digitar 5.6/47. I am pretty sure they did not make a new version of that lens, they just renamed it. I could be wrong...

Dave

I have three different PDF data sheets for the 47, including the Alpa one for the "Helevetar". In all three, the lens parameters are exactly the same. Interestingly, in none of these data sheets is it called XL. Nonetheless, I have heard the claim that the XL version is different.

This link is to the online version on S-K's site from a 2005 crawl by the Internet Archive. The data are the same as the PDF sheets. https://web.archive.org/web/2002080.../photography/digital_photography/47/page1.php

I'm curious if anyone has an "XL" data sheet that has lens characteristics that show differences.

On the data sheet of the 5.6/47 the IC is specified as 60mm, so I think that the MTF represented there goes from 0 to 30mm.
The 47xl should have something like 113mm. So, it seems strange to me that the 5.6/47 is the same lens.

 

[rdeloe]

On the data sheet of the 5.6/47 the IC is specified as 60mm, so I think that the MTF represented there goes from 0 to 30mm.
The 47xl should have something like 113mm. So, it seems strange to me that the 5.6/47 is the same lens.

The web-based data sheet I linked above shows the image circle as 80mm. I saw 60mm on the PDFs I have. The figure 113mm at f/11 comes from a marketing brochure that I have where it's called the XL.

I think some of this is due to changing expectations as sensor technology developed -- rather than changes in the lens itself.

@Rod S. has an excellent collection of S-K material. If he sees this conversation, I'm hoping he can resolve this mystery.

By the way, as has been reported many times on other threads, the "APO-Digitar" 47mm is the same or very close to the same as the Super-Angulon 47mm f/5.6 MC. The MC Super-Angulon 47 has an reported image circle of 98 wide open (same as APO-Digitar XL in S-K's brochure) and 123mm at f/22 (which does line up with 113mm at f/11 from the brochure). If you look at the datasheet for the XL Super-Angulon, it is a physically different lens.

 

[mristuccia]

The web-based data sheet I linked above shows the image circle as 80mm. I saw 60mm on the PDFs I have. The figure 113mm at f/11 comes from a marketing brochure that I have where it's called the XL.

I think some of this is due to changing expectations as sensor technology developed -- rather than changes in the lens itself.

@Rod S. has an excellent collection of S-K material. If he sees this conversation, I'm hoping he can resolve this mystery.

By the way, as has been reported many times on other threads, the "APO-Digitar" 47mm is the same or very close to the same as the Super-Angulon 47mm f/5.6 MC. The MC Super-Angulon 47 has an reported image circle of 98 wide open (same as APO-Digitar XL in S-K's brochure) and 123mm at f/22 (which does line up with 113mm at f/11 from the brochure). If you look at the datasheet for the XL Super-Angulon, it is a physically different lens.

Wow, what a confusion.
We should work on a unified table with all data and all equivalences between the various rebranded LF/MF tech lens models, and keep as a valuable resource in this forum, which is the most specialized on such subject...

 

[mristuccia]

The hypothesis that the Apo-Digitar 47XL is equivalent to the MC Super-Angulon 47 seems reasonable as for both the suggested CFs have the same "II" number, both providing 1.5 stops correction.