Nikkor SW 90mm f/4.5 - What's the closest focus distance on this lens?

[cayenne]

Hi all,

I'm shooting this Nikkor 90mm lens on a Shen Hao view camera.

Does anyone know what the closest distance you can focus with with this lens?

Thank you in advance,

cayenne

 

[138S]

Hi all,

I'm shooting this Nikkor 90mm lens on a Shen Hao view camera.

Does anyone know what the closest distance you can focus with with this lens?

Thank you in advance,

cayenne

It depends on your bellows extension... LF lenses don't have a particular close focus limitation.

Say you have a 190mm max extension (TFC45-IIB), the SW 90 has a flange focal distance (infinite focus) of 97mm. So you can give some 90mm more bellows than when focused at infinite.

Formula is:

1/F = 1/D + 1/B
where F = focal length, D = distance, B = Bellows Draw

1/90 = 1/D + 1/180 (180 is effective as to the 90 focal you add 90mm extension beyond the extension for infinite focus.)

2/180 = 1/D + 1/180

2/180 - 1/180 = 1/D

1/180 = 1/D

D = 180mm. You have to be able to focus something at 180mm. If your max bellows extension it more then you can focus even closer.

Those 180mm are counted from the Front Nodal Point which may be located inside of the front cell, so distance from the front element should be even lower than those 180mm, perhaps 150mm.

Regards

 

[Bob S]

That will depend on your camera’s total extension.
But do be aware that wide angle lenses for large format cameras are not corrected for extreme closeup photography.

 

[cayenne]

It depends on your bellows extension... LF lenses don't have a particular close focus limitation.

Say you have a 190mm max extension (TFC45-IIB), the SW 90 has a flange focal distance (infinite focus) of 97mm. So you can give some 90mm more bellows than when focused at infinite.

Formula is:

1/F = 1/D + 1/B
where F = focal length, D = distance, B = Bellows Draw

1/90 = 1/D + 1/180 (180 is effective as to the 90 focal you add 90mm extension beyond the extension for infinite focus.)

2/180 = 1/D + 1/180

2/180 - 1/180 = 1/D

1/180 = 1/D

D = 180mm. You have to be able to focus something at 180mm. If your max bellows extension it more then you can focus even closer.

Those 180mm are counted from the Front Nodal Point which may be located inside of the front cell, so distance from the front element should be even lower than those 180mm, perhaps 150mm.

Regards

Thank you VERY much!!!

I was having some ideas about trying some experimental close up type shots and see what I could come up with.

Thank you!!
C

 

[Cary Lee]

If I recall that type of work is best used on cameras that have a monorail setup vs a view camera.

 

[Alan Edward Klein]

If I recall that type of work is best used on cameras that have a monorail setup vs a view camera.

Why is that?

 

[koraks]

Why is that?

Monorails tend to have longer bellows and allow for greater movements than view/field cameras.

 

[Dan Fromm]

Monorails tend to have longer bellows and allow for greater movements than view/field cameras.

To expand on this a little, some monorails can be extended indefinitely. This includes most modern (modular) ones, with removable bellows. Older non-modular monorails such as the Calumet CC- series and Graphic Views are limited to the extension the one rail and bellows allow.

 

[locutus]

Also, rear focus becomes very useful at macro ranges.

Remember that this focus distance is front the nodal point not the film plane, this causes the weird effect that at macro distances your focus point moves in strange ways as the lens movement is a significant fraction of the working distance.

Ofcourse, some field camera's have rear focus (my shenhao doesn't..... and i want it) but most monorails already have this.

With rear focus the lens stays in the same position but the film plane moves, thus a lot of complexity goes away.

 

[Craig]

Also don't forget the exposure compensation for the bellows draw. The further you get away from infinity focus, the more exposure you have to add.

 

[ic-racer]

Also, rear focus becomes very useful at macro ranges.

Remember that this focus distance is front the nodal point not the film plane, this causes the weird effect that at macro distances your focus point moves in strange ways as the lens movement is a significant fraction of the working distance.

Ofcourse, some field camera's have rear focus (my shenhao doesn't..... and i want it) but most monorails already have this.

With rear focus the lens stays in the same position but the film plane moves, thus a lot of complexity goes away.

Good point. One can easily set the rear standard in a position (too close to the subject) so that no position of the front standard (while focusing) will ever give a focused image. I found the best way to focus macro is to move the bed or rail (moving both standards at once).

 

[Alan Edward Klein]

Also, rear focus becomes very useful at macro ranges.

Remember that this focus distance is front the nodal point not the film plane, this causes the weird effect that at macro distances your focus point moves in strange ways as the lens movement is a significant fraction of the working distance.

Ofcourse, some field camera's have rear focus (my shenhao doesn't..... and i want it) but most monorails already have this.

With rear focus the lens stays in the same position but the film plane moves, thus a lot of complexity goes away.

I'm new to LF photography. Both my field camera's standards can be moved. Is there a procedure that suggests using one or the other first or combining them? Or doesn't it matter?

 

[Alan Edward Klein]

Also, rear focus becomes very useful at macro ranges.

Remember that this focus distance is front the nodal point not the film plane, this causes the weird effect that at macro distances your focus point moves in strange ways as the lens movement is a significant fraction of the working distance.

Ofcourse, some field camera's have rear focus (my shenhao doesn't..... and i want it) but most monorails already have this.

With rear focus the lens stays in the same position but the film plane moves, thus a lot of complexity goes away.

Please explain why that matters.

 

[Dan Fromm]

Alan, the general rule for closeup/macro work is to set the camera/lens up for the desired magnification and then focus by moving the entire assembly. If slight adjustments to focus are needed and the camera has a movable rear standard, use the rear standard.

For all film-to-subject distances except when magnification is 1:1 (then the film-to-subject distance is, ignoring the lens' internodal distance, 4 focal lengths; this is the minimum, all other magnifications have greater film-to-subject distance) two magnifications are possible. 1:x and x:1. This isn't a problem at low magnifications, but at high magnifications it is much too easy to end up with the wrong (= unintended) magnification when adjusting focus by moving the front standard.

 

[Alan Edward Klein]

Dan, I guess my question was for regular landscape, architectural or portraiture photography not macro. What is best practice for focusing when both standards can be moved?

 

[Dan Fromm]

Dan, I guess my question was for regular landscape, architectural or portraiture photography not macro. What is best practice for focusing when both standards can be moved?

See post #14 above for closeup. At normal distances, well, it depends. With long lenses the front standard is out of reach. With short lenses, moving the front standard as far forwards as possible and focusing with the rear guarantees that the rail won't be in the frame. There's no general rule, moving the front standard is equivalent to moving the rear. Use what's convenient and upsets balance less.

 

[Alan Edward Klein]

Got it. Thanks. My main problem is I need another arm. What with keeping the cloth in place, and moving and tilting the standards, I haven't figure out how to handle the loupe. You have to be a contortionist when shooting view cameras.

 

[Dan Fromm]

Reading glasses?

 

[Alan Edward Klein]

Reading glasses?

I wear eyeglasses and have astigmatism. Any particular type of reading glasses?

 

[Craig]

I wrap the dark cloth around the camera and secure it with a binder clip. That frees up a hand to focus and hold the loupe.

 

[M Carter]

Got it. Thanks. My main problem is I need another arm. What with keeping the cloth in place, and moving and tilting the standards, I haven't figure out how to handle the loupe. You have to be a contortionist when shooting view cameras.

Look into the dark cloths that are sort of like "jackets" that the camera "wears" and you slide up under. Can't recall the name, but many people are crazy in love with 'em. You don't need to hold them in place.