A lens/shutter combo for B&W aerials

[john_kasaian2]

Does anyone know of a coated 300mm lens f6.3 or faster that can be found in a reliable shutter that can do 1/225 or 1/250 AND cover 8x10 thats sharp all the way out to the edges? My Nikkor M 300mm f/9 in it's copal#1 is an excellent lens for color, but if I use any kind of a filter for B&W my negatives come out too thin. I could push the film---I'm shooting Tri-X @ 320 and T-max @ 400---but I'm paranoid of grain(a 35mm days flashback, I suppose) as I want to enlarge to 40"x50" max for a museum display. Thanks for any and all suggestions!

[ken_burns1]

If your negatives are too thin when you use a filter for B&W, the

problem is probably related to an incorrect filter factor. The lens

itself would not be the problem.

[john_kasaian2]

The filter factor is really the problem. Any filter factor I use

requires a slower shutter speed than 1/225 and the image gets blurred

because of the motion of the aircraft. The weakest filter I've used

is a #8. I can try a weaker filter I suppose. though in Steve

Simmon's book Using The View Camera, no exposure increase is

recommended for the #8 filter(p.28.) Are any developers noted for

increaseing density in thin negatives? That might be worth a try

however experimenting with aerial photography is rather expensive.

At least in the winter I can take a ski lift to altitude---lots

cheaper than renting an airplane.

[eugene_singer]

John, the Nikon 300m f9, in the Copal 1 shutter, is as good as it

gets. Anything faster is in a larger shutter and will require larger

diameter filters. Of course, you are already aware of this. I suggest

that you switch to Ilford HP-5, developed in Ilford Microphen 1:1.

The #8 filter requires, at least, a 2/3 stop increase, and the #15

needs, at least, 1 stop, for use with HP-5. Also, HP-5 can be rated

at a true 400 speed if developed in Microphen.

[asher_galloway1]

All the 300mm F6.3 lenses I am aware of like the Commercial Ektar and

the Schneider Xenar are mounted in Acme#4 or Copal or Compur #3

shutters whose fastest speeds are 1/125 sec.Lenses of this size and

larger won't fit in the smaller shutters with the faster shutter

speeds.If they could the demand for your Nikon M,the Fuji C's,and the

schneider G-Claron would'nt be so great.

[richard_boulware]

Your interest in a 300mm lens brings to mind some aerial photograph

know-how I got flying over 2800 air hours doing photo recon for the

Navy Fleet Intelligence Center. The lenses we used were B&L Tri

Metrigon system lenses that were calibrated to four decimal places

and engraved on the lens mount. i.e. 12.0034". If your interested in

razor sharp aerials....try to find some surplus Basch & Lomb Tri

Metrigon lenses. These were serious pieces of glass...even by modern

day standards. Richard Boulware _ Denver.

[clayton_tume]

John

<p>

This might be another way around the problem....have you thought of

trying Tri-X aerial film?

<p>

The closest size would be 9 1/2" roll film so you'll lose a little on

the ends. It's easy to cut down and use in film holders and has

higher contrast than conventional film and extended red sensitivity.

I use it it Cirkut cameras and the contrast takes a bit of working

around for pictorial work.

<p>

The only aerial film I have on hand is Plus-X 2402, this is what it

says in the product info for exposing it.

<p>

<strong>TYPICAL CAMERA EXPOSURE</strong>

<br>

Based on processing to an Effective Aerial Film Speed (EAFS) of 160,

a typical exposure for 2402 film is 1/500 second at f/11. This

exposure is based on the following conditions-a solar altitude of 40

degrees, an aircraft altitude of 5,000 feet, and a clear day.

[mark_sampson]

Why don't you try contacting Kodak Aerial Imaging? i'm sure they'd be

happy to help.

[john_kasaian2]

Thank you all for the excellent advise. I'm waiting for a calculator

Kodak is sending me to work out aerial exposures. I'm going to do a

series of exposures without using any filter just to see how they

turn out. My subjects are granite, ice, snow, and clouds againt a

usually clear,very deep blue sky. It would be interesting to see the

diferences between HP-5+ and T-Max 400 in this enviornment. As far

as cutting down aerial film, it is so expensive that it would be

worth getting an old K-17 K-18 or K-19 and shooting it in rolls with

a focalplane shutters and a trimetrogon lens. Of course I'd have to

find a processor for 9 1/2" film( 3 bath tubs?) FWIW, check out

http://pws.prserv.net/varney/20cms/cameras.htm Thanks again!

[ed_workman]

Try a #3 filter. Less haze cutting but a factor about 1.5 rather than 2. Also can somebody explain aerial film speed vs ASA (now ISO)?.

It seems, by reading Kodak info, that Aerial Speed is figured at a very high contrast index. If so, longer developement might work to increase contrast and apparent speed.

[jim_galli4]

I'd at least consider a 240/9 Fuji A. Added sharpness and contrast by

the extra speed of the Copal 0 (1/500 & 1/250) and multicoating might

well overcome the extra enlargement necessary to get to the same image

size as a 300 will give. After that I'm a diehard 305 G-Claron guy.

I haven't had the pleasure of using a 300 8.5 Fuji C but it would be

Multi-Coated and in Copal 1.

[john_kasaian2]

Ed:I just got the Kodak Aerial Exposure Computer in the mail, heres

the qoute:"Effective Aerial Film Speeds(not to be confused with

conventonal film speeds which are designed for pictorial photography)

for black and white negative aerial films are based on 3/2H, where H

is the exposure(in lux seconds) at the point on the characteristic

curve where the density is 0.3 above base plus fog density." Jim: The

Gowland camera I'm using has a built in lens cone(well, actuallly the

whole camera is the lens cone!) and will only take a 300 mm lens. I

could try shimming for a 305 G-Claron, but at f/9 I'm afraid I'd be

at the same point I am with the Nikkor M(and besides, if I had a G-

Claron, I'd want it on the 'dorff to take advantage of that nice

image circle!). The 240mm Fuji might fit the 5x7 model of this same

camera---that might be worth looking into. Thanks again for all the

advice!