What's a Sinar auto shutter and a DB mounted lens?

I guess the subject line said it all, Sinar users or LF experts, a little help please, just out of curiosity.

Dave

A Sinar shutter (mechanical or electronic) fits on a Sinar (any Sinar)

behind the front lens panel/bearer. Sinar DB mount lenses (or DBM

mount) have no shutter. Instead they all share the one Sinar shutter.

<p>

Advantages:

DB mount lenses stop down to f.45 from behind the camera. DBM mount

lenses stop down to f.90 using a manual override.

If you use DB mount lenses with a Sinar Shutter you never have to set

anything in front of the lens; everything can be set from the back of

the camera. This does enable you to work fast (and in some cases safer:

like when hanging over the edge of the Grand Canyon f. inst.)

The Sinar shutter makes you work a bit like using a single lens reflex

camera.

The shutter stays open until you insert a film holder. Through a

connection cable the shutter then closes and selects the proper f.

stop.

Remove the film holder and the shutter opens again, ready for the next

shot.

Also, the shutter is self tensioning.

<p>

Disadvantages:

Sinar DB and DBM mount lenses are a bit heavier than if they had their

own Copal or Compur shutter.

Also, BEWARE of older Sinar mechanical shutters. They may cause

vibration.

Sounds like the ideal method, like a high tech packard shutter. Can

a Sinar shutter be modified to work in other cameras? Are their

diferent sizes? Is the release cable routed thru the lens board?

The Sinar system has a detachable bellows which connects to the front

standart. This front standart has the same measures for all the

different types and sizes of cameras that Sinar makes. The shutter

goes in between the back of the front standart and the bellows. The

(dedicated) release cable is connected to the side of the shutter.<br>

The shutter is a dedicated Sinar accessory, but I think that it will

also fit Horseman monorail cameras. They are only made in one size,

i.e. to fit the back of the Sinar front standart.<br>

It is possible someone mechanically inclined can modify the shutter

(or preferably the front standart) to fit other brands.<br>

Now, the Sinar shutter is quite useable without a DB lens mounting.

I.e. it is very useable for barrel mounted lenses, in which case you

have to set the aperture as per usual. You just have to see to that

the back of the lens doesn't protude more than 18.5 mm behind the

lens board (on a Sinar camera). If the back of the lens is more than

80 mm in diameter it shouldn't protude behind the lens board at

all.<br>

The Sinar shutter together with DB mounted lenses are very good with

Sinar cameras, especially in a studio on a sturdy tripod/column

stand. But it is also quite useable in the field, if you don't mind

the little extra weight and bulk. You get the advantage of having ONE

shutter, without having to worry about or compensating for

differenties of your exsisting shutters. And, at least here in

Sweden, DB mounted lenses can be found quite cheap.

Just to add to your information, the older ones have a wide aperture

of 5.6 while the newer ones have a wide aperture of 4. Per is

correct. they do vibrate.

Another disadvantage is that mine/they have a maximum speed of 1/60th

of a second, which makes it hard to eliminate or control ambient

light with falsh.

<p>

I think that, with lenses that pertrude behind the lensboard, you can

use them on the rear standard - for flash use anyway.

<p>

I am planning to use mine with my Hasselblad - see Medium format

Digest/K.I.S.S TTL + Studio flash

Since 4X5 Horseman bellows fit Sinar standards and vice versa, I

suppose a Sinar Auto Aperture shutter wuld fit a Horseman camera

without modification. Never tried it, though.

One other thing. If used with the Sinar meter system, the electronic

shutter provides automatic exposure capability with flash and/or

ambient light. I.e. it feeds the readings into the shutter.