Re: Impressions on Nikkor M 450mm f9
Kind of off-topic, but I'd like to make just a small observation about overall flare caused by light scattering in-camera, e.g., from a lens with a large image circle and no lens hood.
This kind of flare tends to be overall fogging flare and will affect the low values, if the flare fog is great enough and the low values are low enough. In that situation, sure, some "crispness" (separation, contrast, however you like to describe it) will be lost in the very lowest values.
However, if the exposure is generous enough to get the low shadow values up "out of the fog," so to speak, the loss in contrast will be negligible, really negligible, in the final print, since the fb+f value, which prints jet black, now includes the flare fog.
In other words, to a great extent one can eliminate the effects of overall fog from stray light scattered by the bellows, etc. by simply overexposing a bit (something a lot of us have built into our exposure regimes already). Sure, using a lens hood is the best solution, but a bit of extra exposure in tricky or demanding situations can often save the day.
Furthermore, it's not always desirable to have the greatest separation possible in the toe area of the film. A lot of people use uncoated, flare-prone lenses just to get the slight overall fog and the softer shadows they produce. One could argue that using a lens with a little bit of flare allows more creative possibilities, since one can control to a great extent the effect of the fog on the lower values with exposure, just like one does with a film with a long curved toe (e.g., Tri-X 320).
Maybe all this worrying about 0.2% scattering is a bit superfluous...
Best
Doremus
Re: Impressions on Nikkor M 450mm f9
Quote:
Originally Posted by
Doremus Scudder
Kind of off-topic, but I'd like to make just a small observation about overall flare caused by light scattering in-camera, e.g., from a lens with a large image circle and no lens hood.
This kind of flare tends to be overall fogging flare and will affect the low values, if the flare fog is great enough and the low values are low enough. In that situation, sure, some "crispness" (separation, contrast, however you like to describe it) will be lost in the very lowest values.
However, if the exposure is generous enough to get the low shadow values up "out of the fog," so to speak, the loss in contrast will be negligible, really negligible, in the final print, since the fb+f value, which prints jet black, now includes the flare fog.
In other words, to a great extent one can eliminate the effects of overall fog from stray light scattered by the bellows, etc. by simply overexposing a bit (something a lot of us have built into our exposure regimes already). Sure, using a lens hood is the best solution, but a bit of extra exposure in tricky or demanding situations can often save the day.
Furthermore, it's not always desirable to have the greatest separation possible in the toe area of the film. A lot of people use uncoated, flare-prone lenses just to get the slight overall fog and the softer shadows they produce. One could argue that using a lens with a little bit of flare allows more creative possibilities, since one can control to a great extent the effect of the fog on the lower values with exposure, just like one does with a film with a long curved toe (e.g., Tri-X 320).
Maybe all this worrying about 0.2% scattering is a bit superfluous...
Best
Doremus
Doremus, just a thought...
PD: next contains a conceptual error, as seen in following posts
Flare originated density and Base+Developing_fog can be compensated with the "pre-flash" light amount a paper requires to start building density.
Flare effect will also increase with the exposure, it's amount will grow linear with image forming light...
For the darkroom perhaps, by overexposing film, the effect is that we separate the Base+Fog vs Image+Flare density, so we can use all the "pre-flash" margin to overcome flare as the Base+Fog density becomes way lower compared to the rest.
In photoshop the thing it's straight, we just remove the flare level in the curve... WYSIWYG
But with slides... we may want just a nice slide, we have a different kind of WYSIWYG, This is What you shot is what you get :)
So if wanting a nice slide we may need a lens with a not too large circle or a front hood... or still we may want flare for the aesthetics...
Re: Impressions on Nikkor M 450mm f9
Quote:
Originally Posted by
Pere Casals
Doremus, just a thought...
Flare originated density and Base+Developing_fog can be compensated with the "pre-flash" light amount a paper requires to start building density.
Flare effect will also increase with the exposure, it's amount will grow linear with image forming light...
For the darkroom perhaps, by overexposing film, the effect is that we separate the Base+Fog vs Image+Flare density, so we can use all the "pre-flash" margin to overcome flare as the Base+Fog density becomes way lower compared to the rest.
In photoshop the thing it's straight, we just remove the flare level in the curve... WYSIWYG
But with slides... we may want just a nice slide, we have a different kind of WYSIWYG, This is What you shot is what you get :)
So if wanting a nice slide we may need a lens with a not too large circle or a front hood... or still we may want flare for the aesthetics...
Pere,
You bring up a good point about slide film. I think in B&W negative terms; for slide film, of course, the less flare a lens has, the better (except when you may want to have a bit of flare or pre-flashing to bring up the shadows a bit. When I shot a lot of transparency film, I'd routinely boost shadow detail a bit in contrasty situations with a bit of pre-flash).
Maybe I'm misunderstanding what you mean, but lens or bellows flare causes exposures in the low-density areas of film. For negative film this is the shadow area. Pre-flashing paper affects the highlight areas. While the effect is similar, pre-flashing paper in no way compensates for in-camera or lens flare.
Back on topic a bit. I just took a look at prices on eBay for the Nikkor M 450mm. Average price now is a lot higher than when I got mine (I paid just over $400). I'm sure glad I got mine then.
Best,
Doremus
Re: Impressions on Nikkor M 450mm f9
Quote:
Originally Posted by
Doremus Scudder
Pre-flashing paper affects the highlight areas. While the effect is similar, pre-flashing paper in no way compensates for in-camera or lens flare.
You are right, it was a conceptual error I had, thanks for explaining it to me.
Re: Impressions on Nikkor M 450mm f9
Quote:
Originally Posted by
karl french
It's a great lens. Excellent optically and quite compact for a lens in a Copal 3 shutter. A very good focal length for 8x10 landscape work.
Thanks Karl. The whole 14 pages is a very interesting discussion. However, you got me from your first post. I just bought a Nikkor M 450/9. I am waiting for my 8x10 to arrive in five weeks.