Kinebohのブログ一覧

Weather Forecast tells that cold temp would last all day long today, so better stay at home if we don't have some specific urgent business. More few days endurance is obliged to get outside for comfortable photo shooting.

A few days have past since I had obtained an old lens produced while WW2 in germany. This marble like equipment gives me an impression.

The light source through lens glass material just before WW2, 85 years ago arrives on the Image Sensor. And on the camera body Ⅲf, Leica DRP is clearly engraved. Deutsches Reichs Patentamt is the meaning. Actuall, it's older than myself, this lens must have arrived at our country passing through under the war fire and explosion, it is survived in front of me. This small goods must last for ever as a living witness of War.

Consulting Leica Lens book, glass coating technology had been invited on Summitar for the first time corresponding to the newly introduced color silver salt film. So, as the innate character of Summitar, not only monochrome film but also color film might be acceptable with enough capability. Actually, color resolution is remarkable at all. Color reproduction is not frivolous but calm and stable---that makes me so satisfied.

However hard I might look for the frame cage in the Web sites, I could not find out the item that is suitable for OM5. Smaller camera body is acceptable for all the photographers without exception. On the other hand, especially when tele lens is invited, too small and too light body is not always convenient. So to speak balanced holding is indispensable fitting on the palm and fingers.
Concequently, applied I the cage for Fuji-film XT-5 onto DS OM-5 with a small modification, just move the fixing hall anteriorly. All the function of the bottons and dials do not lose with this cage.
A big harvest by a cage on OM-5, now it is possible to grasp the lower part of camera body with a little finger as a matter of fact.
This advantage is so clear when 75~300 zoom lens is invited.
This handling effect makes me want to take pictures, which is very much appreciated. Small and light isn't always a good requirement.

Unexpected warmer days are lasting since yesterday, it's like an early spring. Change of pressures causes such a remarkable thermal transition so incredibly. Probably, First Spring Wind must blew 3 days ago. Flowers preparing spring season must have frightened. Blooming timing would be enhanced this year. Early cherry blossom and plum will make haste to bloom.

There is a term Tele-Photo Ratio in the lens design R/D field. It is a ratio that the length of the distance from the anterior surface to image sensor were divided by the actual lens focus distance. The smaller value than 1, the shorter the finished length would be. It must be a good Gospel for the most of the photographer who wanna carry less burdenning. But, things aren't going so well, such kind of modification in designing steps invite much discrepancy, difficulty in correction aberrations. As most of the buyers want to be free from inconvenience caused by the bulk, consumers want to buy smaller and cute one as the newer models.

The engineers in R/D must have been obliged desperate effort by the thoughtless and unreasonable requests. When you violate basic principles, problems arise somewhere, and you have to somehow work around them, so unnecessarily. This results in compromises and compromises---leading becoming worse.

However louder the new announcement might be done in the Website, the newer model does not always overcome the performance of the old model in all the aspect. Consequently, photographers must be obliged to make good decision especially who have some strange desire in his or her deeper part of their heart.

One the other hand, same kind of phenomena is recognized on wide angle lenses. Frontal extension is done to compensate several aberrations, it is called as Retrofocus design. Increasing the glass reflective surfaces does not invite acceptable result, however coating technology might have made progress.

Physical minus fuator never disappears. Fundamental principle cannot be ignored, otherwise unexpected failure might occur without an exception, no matter how someone notice or not.

In Scientific field, Data-backed results, not Emotion, are the priority.

(R/D: Research and Development)

The closest distance is so designed at 1m on Leica old interchangeable lenses some of the later model was 0.7m. On the other hand, those for SLR body were so done at 45cm on standard lenses. Range finder construction had some disadvantage on close distance because of paralux and measuring accuracy. These are why 1m closest distance was designed. Other rangefinder cameras were same as Leica.

I make it a rule to make this disadvantage into advantage without any irreversible modification, just an additive of an adequate extension tube. For example, Summitar extended 20 mm anteriorly could establish infinity focusing with its fuselage collapsed, without fuselage extension as normal use.

Then what will happen when the barrel was extended with extension tube? Yes, more close up shooting would be possible, 23cm distance like a macro lens!

As I show here, all the collapsible lenses could be utilized their performance shown here if an adequate length extension was applied, interesting don't you think?