[ukspeedtraps]

Suns up!



Grab and run shot on the K-1 & DFA 70-200

[luoeven]

My first pic.

[DimC]

My first pic.

Welcome
Nice one.

[Sailor]

Keep fiddling as that shot was great.

Thanks much, my friend, for the very kind words.

Jer

Do you know what makes that clock a "regulator?" Learned a couple years back what it means.

Ain't gotta clue.

Jer

[Erictator]

Thanks much, my friend, for the very kind words.
Jer

Ain't gotta clue.

Jer

My late Cousin the horologist and also clock restorer, would probably have said the pendulum, since basic spring winds weren't as accurate back in the day without one, and a precise weight and rod length on a regulator would get you a lot more accuracy. You saw a lot of these in train stations, post offices, etc, in the early days...

I'll throw one out there, he also built a Foucault's Pendulum in his basement... Wpresto, if you know what that is without looking it up, you win... ummm... got it! You win a smiley cool face emoticon , heh.

I miss my cousin, he was so cool.
Eric

[Gimbal]

Do you know what makes that clock a "regulator?" Learned a couple years back what it means.

I know that more advanced pendulum clocks have the pendel arm built in such a way that temperature variations doesn’t change the length of the pendel, and hence doesn’t affect the clock speed. Is that it?

[JensE]

Do you know what makes that clock a "regulator?"

By somewhat old-fashioned use in German, I'd say it is a fairly precise clock with an enclosed pendulum. The regulation aspect probably originates from use as a reference for other clocks.

[kengoh]

Just a pair of ordinary common birds.
Shot with Tamron 70-200 F2.8

[WPRESTO]

I know that more advanced pendulum clocks have the pendel arm built in such a way that temperature variations doesn’t change the length of the pendel, and hence doesn’t affect the clock speed. Is that it?

Yes. The period (=swing time) of the pendulum is critical to the time-keeping accuracy of a clock that is driven by a swinging pendulum. The period is determined by the length of the pendulum only, not by its mass (~weight). and the length is measured from the pivot to the center of mass, not the tip end. The length of the pendulum will change with temperature, longer when it is warmer (causing the clock to run too slow), shorter when colder (causing the clock to run too fast). "Regulator" clocks solve this by having a mass at the end of the pendulum that expands UPWARD when the temperature rises, thus compensating for the increased length of the main pendulum. Typically, on small Regulator clocks such as the one pictured, common in RR stations, schools, business offices and the like, the regulator mechanism is a series of rods behind the primary pendulum mass (the brass disk at the end) with some bit of mass that the rods "push" upward when the temperature rises. Needless to say, it takes some careful calculation and precise cutting and weighing of materials to make a really accurate regulator clock, but once a manufacturer has determined the values for one particular model/size of clock, they can produce them in thousands. I once saw a massive tall-case ("grandfather") clock that had four glass vials of mercury mounted at the end of the pendulum in addition to a decorative brass piece. I suspect that the mercury expanded as the temperature increased, rising up a tiny bit in the glass vials, and thereby "regulated" the period of the pendulum to compensate for small changes in temperature.

On the clock pictured by Sailor, between the "L" and "A" of "Regulator" there appears to be a thin rod that parallels the much thicker primary pendulum rod. That might be part of the regulating mechanism, but I cannot tell for sure.

[DrBop]

Thanks

More from the D FA* 70-200mm:

Cosimo,

The repeating color and forms in this photo = fabulous! Striking image.

Congrats!

Don

[ZeGaby]

Foggy Night


Pentax K1 + Samyang 8mm Fisheye (Crop mode) 12800 Iso 120s

Orion and Above


Pentax K1 Tamron 70-300mm @ 300mm Iso 6400 20s

The Shadows


Pentax K1 Pentax DFA 100mm Macro Iso 100 f/4.0 HDR by Photomatix Pro then Black and White with Silver Efex

[fs999]

Superb shots ZeGaby !

1. FF Mode • 100 ISO • Sigma Art 18-35mm F1.8 DC HSM


2. FF Mode • 100 ISO • Pentax DA* 55mm F1.4 SDM


3. FF Mode • 100 ISO • Sigma Art 18-35mm F1.8 DC HSM • Haida Pro II-s MC Variable ND filter • Walimex Pro Flash 3xVC-400

[Erictator]

Been slacking... catching up on some posts.

Pentax K-1 smc PENTAX-D FA MACRO 100mm F2.8 WR ƒ/4.5 100.0 mm 1/90 iso100


Pentax K-1 smc PENTAX-DA* 300mm F4 ED [IF] SDM ƒ/8.0 300.0 mm 1/350 iso100


Pentax K-1 smc PENTAX-D FA MACRO 100mm F2.8 WR ƒ/5.6 100.0 mm 1/250 iso100


---------- Post added 01-02-17 at 03:22 PM ----------

Just a pair of ordinary common birds.
Shot with Tamron 70-200 F2.8

Not common here! Heh... nice Kengoh.
Eric

---------- Post added 01-02-17 at 03:23 PM ----------

Foggy Night

Pentax K1 + Samyang 8mm Fisheye (Crop mode) 12800 Iso 120s
Orion and Above

Pentax K1 Tamron 70-300mm @ 300mm Iso 6400 20s
The Shadows

Pentax K1 Pentax DFA 100mm Macro Iso 100 f/4.0 HDR by Photomatix Pro then Black and White with Silver Efex

Very cool ZeGaby! I like!
Eric

---------- Post added 01-02-17 at 03:29 PM ----------

Superb shots ZeGaby !
1. FF Mode • 100 ISO • Sigma Art 18-35mm F1.8 DC HSM

2. FF Mode • 100 ISO • Pentax DA* 55mm F1.4 SDM

3. FF Mode • 100 ISO • Sigma Art 18-35mm F1.8 DC HSM • Haida Pro II-s MC Variable ND filter • Walimex Pro Flash 3xVC-400

Masterful as usual Frederick. Like the mushrooms... your friend is beautiful as ever.
Eric

[fs999]

Thank you Eric ! Superb shots ! I love the butterfly !

[ZeGaby]

Oh thanks Frederic and Eric !

Beautiful shots too !