Lots of lens questions.

[Chris Dunham]

Looking at the copal press-No1 and No 0 shutters for a project and noticed that they are restricted to 125 as the fastest speed, is anyone using these shutters and finding this to be a problem in real world shooting?

Does anyone know the physical dimensions of a Copal Press-No 0 shutter and in particular the overall diameter of the shutter body?

What determines wide open spec of a lens, ie some are 4.7 or 5.6 and go way out to F8 or 9, is it just the design/construction and shape of elements etc or is it also the shutter it's mounted in?

Would it be possible to remount Kodak 203mm front and rear elements in a Copal No 0 shutter?

Thanks all,

Chris.

[John Kasaian]

The top speed of 125 isn't a problem for me if shooting with a tripod.

All the specs for these shutters are on SK Grimes website.

The smaller the number the faster (and more wide open) the aperture. The largest openings are useful when focusing but few photographs are taken "wide open" The faster the lens, generally the bigger the lens. A 300mm f/4.5 will be bigger than a 300mm f/9 and will require a larger shutter to accomodate the size.

Possible to remount a Kodak 203 in a Copal? Yes but it'll cost you---they won't screw right in so you'll need adapters machined---and why? The Supermatics (IMHO) are pretty good shutters and certainly equal to the Copals.

I hope this helps.

[Dan Fromm]

Whether a top speed of 1/125 is fast enough depends on film speed, how bright the light is, and the aperture you want to use. I sometimes find 1/125 too slow for closeup work out of doors when I want to get all of the illumination from flash and not use too small an aperture. It depends on how bright ambient is. Otherwise, not a problem.

[Hiro]

Shutter dimensions data: http://www.sizes.com/tools/shutter_photo.htm.

There are 203mm Ektars produced in Europe (UK?), and they screw right into Copal 0. Mine has "Mount 370" written in front and came in a Prontor-Press (which has the same thread size and mounting surface distance with Copal 0). The aperture scale is another matter.

[Capocheny]

Chris,

I've not had any problems with a top shutter speed of 125 for everyday shooting...

Aperture scales aren't a problem because you can have them made up by either S.K. Grimes or www.lensN2shutter.com.

Alternatively, as with some of the folks here on the forum, you can make them up yourself. Do a search on this forum for the "process/procedure" of calibrating the openings and aperture settings.

Cheers

[Ron Marshall]

1/125 will freeze the motion of a fast walker, moving perpendicular to the field of view, if they are further than about 8 meters from the camera.

If light level is your concern, neutral density filters can be used.

1/125 is the fastest speed I have ever used with LF.

[Chris Dunham]

That's great input, thanks for the info and replies.

Chris.

[Vaughn]

My shutter goes into shock if I use 1/125...the poor thing just isn't use to it (though it does do it accurately.) About 75% of my images are taken on "T", 20% on 1/8 to 1 sec. and the other 5% taken at 1/15 or faster.

Vaughn

[Kevin Crisp]

Chris: A 203 Ektar will not fit in a Copal 0. It will fit, with effort and expense, into a Copal 1. (This is per Steve Grimes when I asked him about it one time. He laughed when I said it might fit a Copal 0) I agree with most else here...

I have never used anything higher than 1/30th for LF tripod work. I do use 1/125th for handheld Crown Graphic shots.

I also agree that the original supermatic shutter on the Ektar, goofy as it may look and as imprecise as it may feel in use, is a pretty decent shutter and with a CLA it should be quite reliable and save you many hundreds of dollars on a remount into a Copal.

[Hiro]

Some, if rare, 203mm Ektars do fit in No.0 shutters (mine came in Prontor SVS, not a Press).
Some others came in factory-fitted Compur 1 as discussed in a previous thread: http://www.largeformatphotography.in...ad.php?t=13476.