Unable to achieve close up focus

ndwgolf · Feb 10, 2019

Hi
I am using a Chamonix 8x10 along with my Kowa Graphic 350mm lens. I was attempting to shot a close up of a white rose but it didn't matter how far i extended the bellows I could not achieve focus,,,,,,,,I was trying to fill the frame with a rose that was about 2inches x 2 inches.
What am I doing wrong?

Neil

Mick Fagan · Feb 10, 2019

In general, to get a 1 to 1 ratio, or same size on the ground glass, you would need 700mm of bellows extension. I think you may need another set of bellows as an extension. Often using another tripod, this is similar to what we did in a studio environment around 35 years ago.

Something like this is what we used, very rarely, we used a triple set of bellows.

https://www.google.com/search?q=dou...AUIDigB&biw=1536&bih=710#imgrc=qVpqe3a3URvljM:

Mick.

ndwgolf · Feb 10, 2019

Mick Fagan said:
In general, to get a 1 to 1 ratio, or same size on the ground glass, you would need 700mm of bellows extension. I think you may need another set of bellows as an extension. Often using another tripod, this is similar to what we did in a studio environment around 35 years ago.

Something like this is what we used, very rarely, we used a triple set of bellows.

https://www.google.com/search?q=dou...AUIDigB&biw=1536&bih=710#imgrc=qVpqe3a3URvljM:

Mick.

Hi Mick
I actually have more than 700mm bellows as I have the Chamonix 8 x10 extension board as well

Neil

Maris · Feb 10, 2019

It is tricky to do close-ups with a front focussing camera. Every focussing movement changes the lens to subject distance, changes the magnification, and changes the focus plane requirement. It is very likely to work through all possible bellows extensions and see a succession of blurry different size images but no sharp focus at any point. Two work arounds:
Set the bellows extension for the magnification required and then move the entire camera as a unit closer or further from the subject to get focus OR set the camera as before and then move the subject back and forth in front of the lens to get focus.
For close-up work back focussing cameras are much easier to use.

AgX · Feb 11, 2019

Maris said:
Set the bellows extension for the magnification required and then move the entire camera as a unit closer or further from the subject to get focus.

Putting the camera on a geared horizontal tripod-extension will be benefitial.

chris77 · Feb 11, 2019

Maris said:
It is tricky to do close-ups with a front focussing camera. Every focussing movement changes the lens to subject distance, changes the magnification, and changes the focus plane requirement. It is very likely to work through all possible bellows extensions and see a succession of blurry different size images but no sharp focus at any point. Two work arounds:
Set the bellows extension for the magnification required and then move the entire camera as a unit closer or further from the subject to get focus OR set the camera as before and then move the subject back and forth in front of the lens to get focus.
For close-up work back focussing cameras are much easier to use.

yes that.

Lachlan Young · Feb 11, 2019

ndwgolf said:
Hi
I am using a Chamonix 8x10 along with my Kowa Graphic 350mm lens. I was attempting to shot a close up of a white rose but it didn't matter how far i extended the bellows I could not achieve focus,,,,,,,,I was trying to fill the frame with a rose that was about 2inches x 2 inches.
What am I doing wrong?

Neil

If you are trying to go above life size, you really need a much shorter focal length - are you trying to get 4x life size? Lighting the object becomes much trickier too as you get closer.

Ian C · Feb 11, 2019

With respect to the information given in post 1:

The 8” x 10” film holder (Lisco) defines an image rectangle of about 245.5 mm x 313.8 mm. A subject whose minor dimension is 2” wide is 50.8 mm wide. A rectangle with the same aspect ratio as the that of the film holder is 50.8 mm x 64.9 mm.

The subject distance s is measured along the lens axis from the subject plane to the first nodal point of the lens. The image distance i is measured from the second nodal point to the image plane.

The magnification needed to make this photograph is 4.83X. At that magnification we get the following combinations of: focal length f, subject distance s, and image distance i.

f = 350 mm, s = 422.4 mm, i = 2014.4 mm

f = 120 mm, s = 144.8 mm, i = 699.9 mm

f = 90 mm, s = 108.6 mm, i = 524.9 mm

Nikon, Schneider, and Rodenstock made 120 mm macro lenses that might be suitable for the stated task.

Deleted member 88956 · Feb 11, 2019

Get the rig on a rail. Focus with camera to close enough, then focus with rail by moving the whole rig, then likely fine focus more with camera, and finalize on the rail if needed. But the general idea of double extension vs. focal length for life size is there, so you can simply measure all distances before even trying to focus. Often framing will be messed up on the first round anyways, depending on subject and tightness of the composition vs. negative real estate and may have to move the entre set up to get it composed as needed with further focusing.

ic-racer · Feb 11, 2019

ndwgolf said:
Hi
I am using a Chamonix 8x10 along with my Kowa Graphic 350mm lens. I was attempting to shot a close up of a white rose but it didn't matter how far i extended the bellows I could not achieve focus,,,,,,,,I was trying to fill the frame with a rose that was about 2inches x 2 inches.
What am I doing wrong?

Neil

Use a lens with a shorter focal length or get farther from the subject.

Eric Rose · Feb 11, 2019

I've even used my 90mm Nikkor lens for closeups when in the field.

ndwgolf · Feb 11, 2019

Heres my first attempt
Chamonix 8x10 Kowa Graphic 360mm Ilford HP5+ Developed in LC29
F9
1/10
Bellows @760mm

awty · Feb 11, 2019

Very nice. Nothing quite like a large format contact print. Now you should practice your tilt to get all the bud in focus. Thats always a challenge with a stupidly big camera, I use two tripods.

wiltw · Feb 11, 2019

Mick Fagan said:
In general, to get a 1 to 1 ratio, or same size on the ground glass, you would need 700mm of bellows extension. I think you may need another set of bellows as an extension. Often using another tripod, this is similar to what we did in a studio environment around 35 years ago.

In general, the amount of bellows extension to achieve 1:1 is very dependent upon lens FL...the subject-to-focal plane distance at 1:1 will generally be 4*FL, for non-telephoto and non-retrofocus optical designs, and the bellows = 2*FL

Dan Fromm · Feb 12, 2019

wiltw said:
In general, the amount of bellows extension to achieve 1:1 is very dependent upon lens FL...the subject-to-focal plane distance at 1:1 will generally be 4*FL, for non-telephoto and non-retrofocus optical designs, and the bellows = 2*FL

Always 4*f + internodal distance. We usually neglect internodal distance for non-tele non-retrofocus lenses because it is usually a small fraction of f for lenses of normal construction.

Ian Grant · Feb 12, 2019

awty said:
Very nice. Nothing quite like a large format contact print. Now you should practice your tilt to get all the bud in focus. Thats always a challenge with a stupidly big camera, I use two tripods.

I bought my first 10x8 camera assuming I'd make contact prints, however as soon as I held my first 10x8 negative I went looking for an enlarger and found a bargain De Vere 5108.

In this case I think it's a case of experience and stopping down a touch to get better sharpness of the rose head itself, movements won't really help.

It's not easy doing macro work with an LF camera, I found that with my Wista 45DX last Autumn some cameras make it easier than others. Currently I'm working with a British made Kodak Specialist 2 Half Plate (7x5) camera, this was also sold for Dental/Medical and Police use. What's great is it has quite a precise track bed with a measured scale, front and rear focussing, an extension rail (with measure) an,d a geared tripod block. This make it easy to use for Macro work, so different to my Wista 45DX.

Ian

awty · Feb 13, 2019

I shouldn't a assume Neil wants the whole bud in focus, have a friend who likes paper thin focus range, I keep asking where's the point of focus ha.
Having a 8x10 enlarger is just bragging Ian and Im envious, took me 6 months just to find a 4x5. I would have to build a whole new darkroom to fit a 8x10, but would be tempting if I ever found one.
I have quite long arms but still cant reach the front standard on my Orbit, these days I use a slide rail, but still a lot of to and fro.....all fun.

The Orbit 8x10 by Paul Fitz, on Flickr

Unable to achieve close up focus

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