July 2023

[Akira]

The area right below this cumulonimbus is in danger of thunder storm...

[Birna Rørslett]

I'm currently experimenting with my ultrafast 'X-ray' lenses and composite panoramas made with them.  The core of each image is very sharp even considering they are f/0.75 (!) designs. however angular coverage is quite restricted if the rendition should meet 'normal' quality criteria. For stitching the aim is to generate so much overlap that only the core remains and thus more broader views can be manifested. However, due to the inherent very short depth-of-field at f/0.75, en focused at 50-100m such lenses have a narrow DOF zone.

Here is a test image  using N=113 images (small jpgs) with the Rodenstock 50mm f/0.75 on the Z9. I made a provisional nodal slide for the lens to reduced the parallax errors in stitching and by and large such errors were reduced although not completely eliminated. I need to fine-tune the slider better, I suppose.

Suburban sprawl encroaching on arable fields are, unfortunately, a common sight around most conurbations in my country. It is extremely short-sighted to use the precious and limited agricultural soils to extend built-up areas. Less than 3% of our area can be cultivated and we can never hope to be self-supported for food production if this deplorable practice continues.

[Akira]

I'm currently experimenting with my ultrafast 'X-ray' lenses and composite panoramas made with them.  The core of each image is very sharp even considering they are f/0.75 (!) designs. however angular coverage is quite restricted if the rendition should meet 'normal' quality criteria. For stitching the aim is to generate so much overlap that only the core remains and thus more broader views can be manifested. However, due to the inherent very short depth-of-field at f/0.75, en focused at 50-100m such lenses have a narrow DOF zone.

Here is a test image  using N=113 images (small jpgs) with the Rodenstock 50mm f/0.75 on the Z9. I made a provisional nodal slide for the lens to reduced the parallax errors in stitching and by and large such errors were reduced although not completely eliminated. I need to fine-tune the slider better, I suppose.

Suburban sprawl encroaching on arable fields are, unfortunately, a common sight around most conurbations in my country. It is extremely short-sighted to use the precious and limited agricultural soils to extend built-up areas. Less than 3% of our area can be cultivated and we can never hope to be self-supported for food production if this deplorable practice continues.

An amazing pano image that one should view large.

[armando_m]

shot with my phone
I think saturation is a bit crazy

[golunvolo]

Birna, those results do looks better bigger as Akira suggested. The separation and detail are something special!

  Today,this little one posed for my without fear for a while. I only had the 24-70 f4 with me so, even this is very close as this lens go, it is still a considerable crop. The resulting image square is aprox 2700 by 2700 pixels

[Birna Rørslett]

Thanks, Akira & Paco. Yes, I'm slowly learning by trial and error.  Getting the nodal slider correctly aligned is crucial,  but it is no secret the stitching engine(/s) can choke on the peculiarities of the 'X-ray' optics. I might move over to using the Z30 instead to get less of the recorded frame being cropped away.

The original image is about 15000 x 6000 pix and as seen by the 100% crop below, there are lots of fine detail. (also visible at the upper edge is a slight registration mismatch, but I didn't bother fixing these as this is purely a test image). Recommended to open the image in a new tab and click it to 100%. That this is f/0.75 and the lens is 60+ years old??

[golunvolo]

Impressive

[Akira]

Thanks, Akira & Paco. Yes, I'm slowly learning by trial and error.  Getting the nodal slider correctly aligned is crucial,  but it is no secret the stitching engine(/s) can choke on the peculiarities of the 'X-ray' optics. I might move over to using the Z30 instead to get less of the recorded frame being cropped away.

The original image is about 15000 x 6000 pix and as seen by the 100% crop below, there are lots of fine detail. (also visible at the upper edge is a slight registration mismatch, but I didn't bother fixing these as this is purely a test image). Recommended to open the image in a new tab and click it to 100%. That this is f/0.75 and the lens is 60+ years old??

Indeed, especially considering that the lens is never designed to focus at this distance AND at f0.75!

[Birna Rørslett]

Actually, as I focused the lens on the house facade and the distance was about 60m, the design criteria of infinity focus was approximated. About 1000 times focal length. Meaning the effective f-number also was close to the nominal f/0.75 (shutter speeds were around 1/15000 sec at ISO100).

These lenses were extremely expensive in their time., It is easy now to realise why. Quality never comes cheap.

[Thomas G]

... from a local cycle loop yesterday (July 10th)

[Fons Baerken]

that's right

..of mice and..

July 1

Z fc 23mm f/1.4

[Birna Rørslett]

Birna : Double self-portrait, and an X-ray scan showing her newly discovered acoustic neurinoma [vestibular schwannoma] (arrowed). At present, I only suffer from severe tinnitus and head aches, however if the tumor grows it can be unpleasant and dangerous even life-threatening, so an operation might be called for in the near future.

The double portrait was taken whilst I was awaiting the latest scan results. Two spirits may not suffice for a trans woman? There are so many hurdles to overcome on the way to a new, brighter, and meaningful existence. One just has to take the challenges as they manifest themselves, and always be prepared for the unexpected. On that path lies danger -- and hope.

[Luc]

Sad to read this Birna. I hope treatment is possible. I'm sure you"ll stay positive. Stay strong, all the best!

[Fons Baerken]

Birna may you be well!

[Akira]

Birna, I hope you to get well soon!