Bellows extension rule of thumb

[Willie]

Your 210 is about an 8 inch lens. So - figure f/8. Extend the bellows to 16 inches and figure f/16. Two stops compensation. Not perfect, but close enough for "zone" system type of figuring on exposure compensation. Easy to figure with a 6 inch lens(150) or a 12 inch lens(300). Again - not perfect, but close enough to work for most of us. You figure "inch" to f/stops and keep it simple.

Use the "inch conversion" method for figuring exposure compensation for bellows extension and it is pretty easy. A lot easier for those of us who are mathmatically challenged. Some of us hear "formula" and think of race cars rather than X and Y and computations.

[Jim Galli]

Here's the hillbilly method I use in Tonopah Nevada. I get the image I want on the ground glass. i could give a flying rip about magnification etc. I measure the hole up front with a ruler. I measure the distance from where my guess about the node, ie. aperture blades, to the ground glass. Plus or minus a half inch is no big deal for hillbillies. Then I divide the size of the hole into the length. That gives me an aperture number. Measure available light and come up with a viable exposure.

I don't care what the numbers on the lens say. Hell, some of my lenses don't even have any numbers and never did. For example, I get an image I like on the glass. I measure the hole up front. 36mm. I measure the length from aperture to ground glass. 820mm. 820/36=22.777777777777777 I measure and expose for f22 2/3. Simple simon. You'd be amazed at how many good pictures I've taken this way.

But I fully understand that other peoples minds do not function at the simplicity of mine and all the mathematics is important. Even fun! I therefore return you to your previous discussion.

[ndwgolf]

Okay so my new Rodenstock Macro 210 arrived and yesterday I picked this flower to try my hand an a close up. I must admit I really struggled in getting the focus, what I did in the end was set the bellows extension on my Chamonix 8x10 to 420mm and then pretty much had the lens nearly touching the flower, from there I just moved the camera back slowly while looking at the ground glass and bobs your uncle the flower came into focus.............i fine tuned it but to be honest I would move the bellows out 1 inch and back 2 inches and nothing really changed so took the picture and here it is.
I also did the same process with a really nice lily with the bellows set at 630mm but screwed up the exposure as I was trying to get an Incident light reading on my Seconic 758 but it was set to spot metering...............I will try that again tomorrow



Neil

[Jim Galli]

Okay so my new Rodenstock Macro 210 arrived and yesterday I picked this flower to try my hand an a close up. I must admit I really struggled in getting the focus, what I did in the end was set the bellows extension on my Chamonix 8x10 to 420mm and then pretty much had the lens nearly touching the flower, from there I just moved the camera back slowly while looking at the ground glass and bobs your uncle the flower came into focus.............i fine tuned it but to be honest I would move the bellows out 1 inch and back 2 inches and nothing really changed so took the picture and here it is.
I also did the same process with a really nice lily with the bellows set at 630mm but screwed up the exposure as I was trying to get an Incident light reading on my Seconic 758 but it was set to spot metering...............I will try that again tomorrow

Neil

Neil, not to confuse you further, but did you know you can take the back off the camera after it's focused, grab an old film Nikon, take the lens off and hold it (the camera body) so that part of your image lands on the Nikon mirror and gg, and that old Nikon will tell you what it would shoot it at.

Nice shot, well done.

[Dave Wooten]

Neil, not to confuse you further, but did you know you can take the back off the camera after it's focused, grab an old film Nikon, take the lens off and hold it (the camera body) so that part of your image lands on the Nikon mirror and gg, and that old Nikon will tell you what it would shoot it at.

Nice shot, well done.

Wow! Didn't know that!

[ndwgolf]

Neil, not to confuse you further, but did you know you can take the back off the camera after it's focused, grab an old film Nikon, take the lens off and hold it (the camera body) so that part of your image lands on the Nikon mirror and gg, and that old Nikon will tell you what it would shoot it at.

Nice shot, well done.

Thanks for that.
It’s the second time I’ve done this screw up with the meter. I will make a sticker for it to remind me in the future.
Neil

[Jim Noel]

Your 210 is about an 8 inch lens. So - figure f/8. Extend the bellows to 16 inches and figure f/16. Two stops compensation. Not perfect, but close enough for "zone" system type of figuring on exposure compensation. Easy to figure with a 6 inch lens(150) or a 12 inch lens(300). Again - not perfect, but close enough to work for most of us. You figure "inch" to f/stops and keep it simple.

Use the "inch conversion" method for figuring exposure compensation for bellows extension and it is pretty easy. A lot easier for those of us who are mathmatically challenged. Some of us hear "formula" and think of race cars rather than X and Y and computations.

I'm with Willie. ALthough I know and can calculate various formulae mentally, it is faster, and close enough to relate bellows extension to f-stops.

[Jim Noel]

If I know I want 1:1 or close to it, i set the bellows at 2x focal length of lens, and the object the same distance in front of the lens. Make minor adjustments, and Increase exposure 2 stops.

[Larry Gebhardt]

i fine tuned it but to be honest I would move the bellows out 1 inch and back 2 inches and nothing really changed so took the picture and here it is.

Neil,

If your camera focuses by moving the front standard you are changing the magnification while you change the focus. You might get into a situation where you can't achieve focus. So what you need to do is either focus by moving the rear standard only, or move the whole camera in and out without changing the focus (length of the bellows). On the Chamonix 4x5 you can coarsely slide the rear and this can work in a pinch. I'm guessing your 8x10 is the same. Or get a heavy duty macro rail to move the camera.

The rear focus for macro is one of my favorite features of the Canham MQC and most/all monorail type cameras.

[Jim Galli]

Here's what you need. The whole monster rolls back and forward on the stand's wheels while you look at the glass. The old timers sort of knew what they were doing. I'm an old timer.