s.k. grimes inc

The PDN/Javitts show is open to anyone in the trade. An assistant

photographer at a University is certainly "in the trade" I

registered on line but a friend who came along with me simply

registered at the front desk. He is an amateur large format

photographer and equipment enthusiast.

<p>

The point is its open to anyone who is "in the trade" They don't

require anyone to "prove" they are "in the trade" I think they

convey that information because the show would not be of particular

interest to the ordinary amateur snapshooter.

<p>

I thought the show was excellent and well attended. I visited with

Canham, Wisner, Schneider, RTS, Walker/Bromwell, Arca Swiss, etc

etc. Even Marty Forscher was there saying "hello" to old friends.

<p>

Steve Grimes

Most manufacturers use a sort of flexible plastic "blow molded" out

of flat stock. There's a general perception that lenscaps should be

inexpensive. (When the U.S. Navy spends $150.00 for a lenscap its

considered one of those government contractor corruptions.)

<p>

So its difficult to justify the added expense of a really good

lenscap on an already high priced product.

<p>

See: <a href="http://www.skgrimes.com/caps/index.htm"> My lenscap

page </a> for some pictures of these.

<p>

Although your experience with the light duty caps is not an everyday

one its cerainly not unusual. I make custom lenscaps of Delrin or

other rigid ABS plastic which are more rigid than the usual blow-

molded factory originals.

<p>

See:

The truth is that an f-8 lens will deliver only f-8 even if its in a

shutter whose iris goes larger. (Sort of like a 50 horsepower car

will only go 75mph and fitting it with a speedometer that goes to

125mph won't make any difference.)

<p>

SKG

The most accurate way to test a shutter speed is by experiment with

film. Be sure of all the parameters except the shutter speed.

Expose film and by densitometer or other method backtrack to tell

what the shutter speed actually was.

<p>

This is an excercise that used to be conducted at photography schools

to determine a "working ASA" for any given film which would integrate

all errors of shutter, glass transmission, developement techniques,

etc. Its still a useful experiment to see what's going on.

<p>

Shutter speed testing with instruments has always been a problem.

Although it would seem simple the problems of "efficiency" (That's

the percentage of the time the blades spend opening and closing,

yeilding a greater length of time open at the center than at the

edge) and just the way light seems to shine around render this a more

difficult challenge than one would think. This problem seems to show

up mostly at the fastest speeds.

<p>

The film density after developement method allows you to test your

shutter tester. I have never done this test myself, not being a

photographer but remember it as part of the first year curriculum at

photo schools.

<p>

I have, on experiment (some ten years ago on a modern Kyoritsu

tester) taken a dozen brand new Copal #0 shutters and they have all

tested very closely to each other at 1/200 second or a full stop

slower than marked. It seems to me that this is more a test of the

test than a test of the shutters, since Copal is a well established

brand made in modern factory and designed by skilled engineers.

<p>

Trying to get a shutter to do something that it just won't do leads

to a lot of grief.

<p>

SKG

Springs used within their design elastic limits do not "know" whether

they are stretched, relaxed or compressed. It makes no difference.

So, the best option is one in which the iris and shutter blades are

opened so as to avoid accidental mechanical damage.

<p>

A stopped car engine, for example has some of its valve springs

compressed and some relaxed. Even if stored for an extended period

there will be no difference to the springs which will still all be

alike.

<p>

SKG

Some photographers prefer to use the locating screw as a security

against the shutter loosening on the lensboard and that's an OK use.

It is extremely rare to see shutters with this properly installed.

In actual practice this screw causes a great deal of harm since it's

usually ignored and tightened against the board causing the shutter

to be tilted and not able to tighten onto the board. The usual

practice is to continue to overtighten the retainer and or the front

element into the shutter/board until it stops wobbling or until the

shutter casting breaks. For this reason its no longer supplied with

new shutters so, if you actually want to use it for whatever good

reason you have then you need to specifically ask for its

installation. If not mentioned I routinely remove and discard that

screw since the other later damage is caused by another phogographer

breaking the shutter mechanism by trying to unscrew it from the board

unaware that there is such a then hidden screw.

<p>

The actual throwback reason for the screw is where "timing"

(clockwise orientation) of a shutter is critical, such as

installation of a shutter in a folding rollfilm camera or

installation on a lensboard with a flash solenoid or remote cable

release fitting.

<p>

An advantage of throwing away the screw is that you don't have to

worry about finding it later.

<p>

SKG

The solution to Presbyopia ("old eye vision") is reading glasses. So

called "Plus Spectacles" are, in my opinion one of the greatest

technical inventions of all time. They are so simple as to make

explanation difficult. Plainly put, the more the plus the closer you

can get to the thing you are seeing and be in focus. When looking at

a ground glass you are looking at the glass itself, not the object in

the picture. So the problem is exactly the same as in viewing fine

print.

<p>

You can experiment with drug store spectacles available in up to plus

4 strengths. You can also add spectacles together (wear two at the

same time). If nothing else, this can help you let your optician

know what prescription you need for your use.

<p>

There is no "wrong prescription" in reading glasses. The only

variable is the focusing distance from the object viewed. Reading

glasses will not "hurt your eyes"

<p>

The special viewing devices used by surgeons are actually spectacle

mounted telescopes which are different from reading glasses (plus

spectacles) in that they magnify objects at a distance (in this case

about three or four feet) rather than allow you to get close to the

object viewed (and still be in focus) as with reading glasses or

ordinary jewellers loupes.

<p>

SKG

You can use the diopter system of lens "power" to estimate this. I

forget the formula for diopters but it runs: 1000mm =1 500mm=2,

250mm = 4, etc. This is a system used to reference the focal length

(known as "power") of spectacle lenses. These add together in a

simple fashion. For example, two one diopter lenses placed one over

the other yield a two diopter system (500mm). This is put in

practice when you wear two pairs of spectacles at the same time.

Similarly, a plus 1 lens (1000mm) and plus 2 lens (500mm) combined

yield a plus three (333mm focal length) system.

Click:<a href="http://www.skgrimes.com/popsci/index.htm"> HERE </a>

to see what I have on lens cementing. At the bottom of that page is

also a link to a reprint of a 1943 Popular Science reprint of a Do It

Yourself article on the subject.

I can make any threaded flange for any lens on short notice. I add

flanges to the stock list after several have been needed or ordered.

For the 72mm size there are at least two possible Metric pitches of

the same diameter. The best thing, in any case where there is doubt

or uncertainty about Metric/English/Pitch/Diameter is to send along

the lens barrel or shutter and have me pick the right flange out of

stock or fabricate one to fit. It takes less time to make a just

right sized flange than to pack and ship and process returns of

different wrong sized flanges sent. For an additional $15.00 I will

install the flange on your lensboard so that what you get back is

complete and ready to use.

<p>

See <a href="http://www.skgrimes.com/flanges/indexm.htm">Click

here</a> to visit a list of some of the Metric Sized mount flanges in

stock.

The lens groups unscrew from the shutter like a bottletop from a

bottle. Turn counterclockwise to loosen.

<p>

They are often stuck in place and require a fair amount of force to

loosen if they are in that condition.

<p>

Steve Grimes. <a href="http://www.skgrimes.com"> www.skgrimes.com

</a>

New Copal parts are available exclusively from C.R.I.S.

www.criscam.com. (RTS is the wholesale distrubutor of the shutters

themselves, not parts)

<p>

Compur parts are handled by Schneider, USA www.schneideroptics.com

That is a picture of a Calumet rotating spring back.

<p>

There's a picture of a Graflok back for auction at

http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1222195778 Or

just search eBay (www.ebay.com) for "Graflok"

These American made lenses do not take any ordinary metric size

filters. Its best to have an adpater made (either slip over or screw

in) to convert the lens to a standard Metric size, probably 49mm in

this case. See: http://www.skgrimes.com/slipon/index.htm for info

about the kind I make.

That lens is suitable for use on 8X10 for portraits. It is a single

element lens (actually, a cemented doublet) with the glass behind the

iris. They usually have a glassless deco ring fitted to the front of

the shutter so it doesn't look too weird to the bank president or

admiral who's portrait is being taken.

<p>

You can get similar results using binocular objectives or spectacle

lenses of suitable focal length.

Any 1/4-20 Screw of a right length can be used. It will probably

work better if the thread is "releived" near the neck like your

original. That necking down can be done easily on a metal lathe, or

by holding the screw in a 1/4" electric drill and using a file.

<p>

1/4-20 is a usual hardware store USA size.

There is an abundance of old pretty good oscilloscope camera lenses

around that are good for this kind of close up photography.

Typically they are 75mm focal length, but not wide angle. They will

only fill the frame on 4X5 when used close up.

<p>

SKG

Use 35mm camera body caps as the interchange medium. (Bore a hole in

the body cap and affix the pinhole foil with glue or tape) Leica or

Pentax thread ones are inexpensive accessories and the lensboard can

be threaded or a Leica or Pentax thread mount fitted to it.

<p>

Or, an extension tube from any 35mm camera can be affixed to the

board by a simple a means as epoxy or hot-melt glue. (such as Nikon)

and then Bayonet type body caps can be used from that camera if you

need a turn and click type mount.

<p>

The View camera interchangeable panels were a copy of the Meridian

camera system made by someone in Tennessee. (M/C Photographic) I'm

pretty sure they are out of that business and that set-up would have

been considerably more expensive than multiple Arca boards.

<p>

SKG

Regular #4 shutter takes a 2.604" diameter hole to mount it.

<p>

SKG

See: http://www.skgrimes.com/iris/index.htm for a page about the

iris scales I supply.

There's no hard and fast rules about this. Most barrel lenses need

to have modifications done and/or adapters made to fit into

shutters. A good rule of thumb is that the iris diameter of the

shutter must be as large or larger than the iris diameter of the

original lens barrel.

<p>

See: http://www.skgrimes.com/lensmount/index.htm for a page about

lens remounting in general. See:

http://www.skgrimes.com/fits/index.htm for a page with a table

showing an anecdotal list of various lenses fitted to shutters based

on my experience doing this.

<p>

SKG

Surprisingly there are some variations between "identical" lens iris

scales as supplied by lens manufacturers. This may be because of

manufacturing conveniences or "rounding off". I really don't know

why. I always prefer to have on hand the original factory iris scale

from the lens in question. Second best thing is that I consult my

records and/or look to see if I have another factory original shutter

or lensbarrel for that same lens. The last resort if no original

and no sample or record is on hand is to install the lens into the

shutter and open the iris until the iris just stops being visible as

it is opened. This, in ordinary lenses, corresponds to the maximum

aperture marked on the lens. Such as, in the case of a f-5.6 150mm

lens where it says 5.6 around the name ring. With that set, I

measure the diameter and apply the formula fd=fl to determine

a "trial" focal length, which should be approximatly 150mm. I use

that trial focal length to calclulate the diameter of the other

remaining stops.

<p>

Steve Grimes.

There is a difference between a flange and a retainer. These

shutters usually use a retainer. I have both on hand depending on

what you want. See: http://www.skgrimes.com/adapter/index.htm for

an explanation and pictures of the difference.

<p>

SKG

That's sort of an oddball adapter that has to be specially made.

<p>

See: http://www.skgrimes.com/boardadapters/index.htm for some

pictures of the ones I make.

<p>

Steve Grimes

I'm a big fan of replacing the older and older Compur shutters with

nice new Copal shutters. It can save time and trouble to just

replace it with new. The iris scale must be made up or gotten from

the lens manufacturer. (I include iris scales on the shutters I

supply.)

<p>

See: http://www.skgrimes.com/products/index.htm for info about Copal

shutters.

<p>

(Please note I am not associated with the company in Boston

called: "S.K. Grimes Camera Repair")

<p>

SKG