300 Nikkor lens

[Raymond Bleesz]

I'm still testing the waters with this lens---using it on an antique Scovill 6.5 x 8.5 Albion Field Camera with 5x7 film inserts (300mm & 5x7 film)---I'm using the lens/camera to take portraiture. With this in mind, how many feet between subject & camera would provide the best focusing distance and suggested F stop. At present, I'm around 8-9 feet. How close can I get to the subject with this lens in mind?

Thank you

[xkaes]

Nikon made several 300mm LF lenses. Which one do you have?

[Tin Can]

I use this often

https://dofmaster.com/dofjs.html

[Alan Klein]

This one gives a little bit more info.

https://www.pointsinfocus.com/tools/depth-of-field-and-equivalent-lens-calculator/#{%22c%22:[{%22f%22:20,%22av%22:%2222%22,%22fl%22:300,%22d%22:1183,%22cm%22:%220%22}],%22m%22:0}

[drew.saunders]

What do you mean by "portrait"? With a roughly 5x7" sheet of film (I know the actual image is smaller), a tight head shot might be a 1/2 life size, or almost 10x14" subject. Maybe 1/3 life size for 15x21" for a more normal headshot, or head and shoulders. 1/4 gets you 20x28" etc.

Let's go with 1/3 life size. Ken Lee has some very useful formulas here: https://www.kennethleegallery.com/html/tech/bellows.php
With a 300mm lens, (see the "How Much Bellows Extension Do We Need ?" formula) you need 400mm of bellows extension.
From "How Close Can We Get?" you get 1199mm distance, or about 4'.

If you're thinking 1/4 life size, the bellows are 375mm and the distance is 1.5m or 5'.

How close you can get is a function of your bellows. I'm guessing your camera has at least 400mm of bellows, so you should easily get as close as you need for portraits.

Using https://www.pointsinfocus.com/tools/depth-of-field-and-equivalent-lens-calculator/ that Alan recommended, a 300mm lens, at f/5.6 for 5' distance gets you a total of 1.33" of depth.

At 8' and f/16, you get 10.69" DoF, which is likely more of what you're looking for.