Re: Schneider Componon 300mm f5.6 on 8x10 camera?
The Componon is a variant of the Symmar that has been optimised for high magnification work, i.e. enlarging and macro. It had the same elements in the same cells but the spacing was slightly different.
Early Symmars were in Compound 3 shutters, later they went to Copal 3 which is a larger thread size so I imagine the Componon would be the same. As Jackpie has said, most donor shutters come with the lens attached and a 300 Symmar probably falls into that category so you would be better just waiting for a bargain on a 300 Symmar than fiddling wit e Componon.
Re: Schneider Componon 300mm f5.6 on 8x10 camera?
Paul, like you I understand that the Componon is a Symmar tweaked for enlarging but I'm not so sure about what the tweak is. I know that changing cell spacing changes focal length; I'm not sure that it changes the conjugates for which the lens works best. So I need to be enlightened on exactly makes a Componon an enlarging lens.
Reyno, interesting idea, that hot spot. Have you seen it?
Re: Schneider Componon 300mm f5.6 on 8x10 camera?
Initially the tweak was separating the front group, as shown in the lens diagrams below. Later diagrams for the Componon show it the same as the Symmar so I don't know if they changed it back again or used the wrong diagram. Unfortunately I don't know how this optimises macro performance. I guess other possible tweaks would be increasing or decreasing the distance between the cells or maybe even adjusting the position of the diaphragm although that wouldn't do much wide open.
I have been wading my way through Schneider brochures and other sources of information for eighteen months or so and although I know more now, I don't necessarily understand what I know :)
http://www.paulewins.com/old_site/re...%20diagram.jpg
http://www.paulewins.com/old_site/re...%20diagram.jpg
Re: Schneider Componon 300mm f5.6 on 8x10 camera?
Quote:
Reyno, interesting idea, that hot spot. Have you seen it?
hi yes i got a hot spot on all my shots when the comp was used in the regular way, but not when used at distances under 2 metre.
i reversed the lens and it worked well at mid - infinity, no hot spot any more.
shutter controls are difficult when reversed but if you are in a barrel then it wont matter
i only used this lens due to my budget of 10 euros for my home made 10x8, if you have the cash buy a better lens
http://www.apug.org/forums/portfolio...8&what=&page=2
second row first pic is the comp 210mm on a foamcore camera
Re: Schneider Componon 300mm f5.6 on 8x10 camera?
Cell spacing can change flatness of field. The rays that come from the center are not refracted much and not affected much by cell spacing. Rays from the edges are more affected by cell spacing, thus the potential for altering flatness of field one way or the other.
Good pickup on the similarity between the Symmar and Componon, I was not aware of that.
I have a 360mm Componon, that is a big lens! I did try screwing the cells into the two different #3 shutters I have but it did not fit either of them.
Re: Schneider Componon 300mm f5.6 on 8x10 camera?
ic, in Schneider-speak Componon = enlarging Symmar, Comparon = enlarging Xenar, Componar = enlarging Radionar
Reyno, I believe you but I'm not sure that what you report is due to the lens. This because I tried shooting a 100/5.6 Componon-S and a 105/5.6 Componon at distance and didn't get a central hot spot.
Re: Schneider Componon 300mm f5.6 on 8x10 camera?
ic-racer, the earlier (chrome nose) 360 fits into one of the Compound 3 or 5 shutter variants, as I recall. I used one for years on my 8x10 with a Packard until the price of Symmars got down to a point where it didn't make sense anymore not to buy one.
Re: Schneider Componon 300mm f5.6 on 8x10 camera?
Quote:
Reyno, I believe you but I'm not sure that what you report is due to the lens. This because I tried shooting a 100/5.6 Componon-S and a 105/5.6 Componon at distance and didn't get a central hot spot.
thats cool, its just my experience, others might find they get different results.
i now more regulary use a aldis barrel lens instead of the comp 210
Re: Schneider Componon 300mm f5.6 on 8x10 camera?
I use a 360mm Componon with a Packard shutter on my 11x14, so a similar solution should work here. Similarly, I use a 210mm Componon on my 4x5 RB Auto Graflex SLR.
Re: Schneider Componon 300mm f5.6 on 8x10 camera?
The 360/5.6 Symmar used a Compound 4. When the Compound shutters were discontinued it went into a Copal 3 and became the 355/6.8. (According to the literature the actual focal length of both lenses was 358mm). After the changeover (late 1970) there was only one more batch of 360 Componons made (15 units) so I think all of the 360 Componons would have fitted straight into a Compound 4.