Reid
Newbie
There is a wealth of information on this topic on the internet, giving much detail on the causes and manner in which it can be dressed out but I can find nothing on what circumstances lead to the formation of these unsightly deformations.
Earlier this year I bought a fine example of a Zeiss Ikon Contax 2a and as yet, there is absolutely no trace or even the tiniest indication of a 'bump' and I would like to keep the camera in this condition. It is a 'user' and not a show case glamour queen but I would be sorry if traces started to show during my time of ownership and caused by my ignorance or negligence. So how can one avoid these unsightly blemishes, which affect not only Zeiss of course but many other cameras particularly ones from the mid '50's'.
A well known fine camera dealer in Europe is offering on his web site a collection of six Contax 2's all from roughly the same build/year and all in heavily used condition; I assume a consignment / job lot from a defunct newspaper or magazine. The condition of each camera is fairly even with the exception of the 'bumps'. One has no discernible bumps, the other four have various quantities and sizes and the sixth one is unbelievable. A moon like surface utterly despoiled, with some truly enormous bumps and fissured leather.
So my question is, what has caused the difference and therein how to ensure my camera, plus a cosmetically fine Kiev, also in my possession , may reasonably escape such disfigurement.
Thoughts lead to high/low humidity; long periods stored in their leather cases, though with respect to the Contax's mentioned above, they would not have been able to enjoy a period of storage. Perhaps extreme cold / hot weather ? being used by very heavy smokers - nicotine reacting with the leather adhesives - not so far fetched mindful the prevalence of smoking in the '50's and 60's'. I would welcome thoughts on possible catalysts to 'bumps'.
Earlier this year I bought a fine example of a Zeiss Ikon Contax 2a and as yet, there is absolutely no trace or even the tiniest indication of a 'bump' and I would like to keep the camera in this condition. It is a 'user' and not a show case glamour queen but I would be sorry if traces started to show during my time of ownership and caused by my ignorance or negligence. So how can one avoid these unsightly blemishes, which affect not only Zeiss of course but many other cameras particularly ones from the mid '50's'.
A well known fine camera dealer in Europe is offering on his web site a collection of six Contax 2's all from roughly the same build/year and all in heavily used condition; I assume a consignment / job lot from a defunct newspaper or magazine. The condition of each camera is fairly even with the exception of the 'bumps'. One has no discernible bumps, the other four have various quantities and sizes and the sixth one is unbelievable. A moon like surface utterly despoiled, with some truly enormous bumps and fissured leather.
So my question is, what has caused the difference and therein how to ensure my camera, plus a cosmetically fine Kiev, also in my possession , may reasonably escape such disfigurement.
Thoughts lead to high/low humidity; long periods stored in their leather cases, though with respect to the Contax's mentioned above, they would not have been able to enjoy a period of storage. Perhaps extreme cold / hot weather ? being used by very heavy smokers - nicotine reacting with the leather adhesives - not so far fetched mindful the prevalence of smoking in the '50's and 60's'. I would welcome thoughts on possible catalysts to 'bumps'.
markjwyatt
Well-known
From what I recall they are caused by the chemicals used to prepare the surface and/or bond the leather to the camera. As to variations, I am not sure. I bought my Contax iia on ebay, and it came with two small bumps. I had it CLA'd, and it came back with none, so I am happy. Mine is a user also; though in pretty good condition.
aizan
Veteran
it’s all because of storage conditions. enough humidity makes the copper corrode.
store it in a box that’s 35-55% RH. add some silica gel packs and a humidity indicator card.
store it in a box that’s 35-55% RH. add some silica gel packs and a humidity indicator card.
raid
Dad Photographer
View the bumps as beauty marks, and leave them alone 
css9450
Veteran
I owned a Contax briefly, and it had a couple prominent bumps. They'd been there so long the surface of the leather over the bump was smooth and shiny from wear! I'd always just assumed there was a rivet or something there that caused the bump.
wes loder
Photographer/Historian
The chemicals used to tan leather can react with copper/brass. The result is a copper carbonate called verdigris, a green, waxy stuff that pushes the leather away from the metal, hence "Zeiss bumps." Camera makers that used vulcanite (i.e. Leica) or leatherette (late Nikons, etc.) are immune. Originally the brass surfaces were sealed before the leather was glued on, but moist storage conditions can cause the bumps anyway. Keep your camera dry, and you may be okay. I have four pre-war Tenaxes. Two have bumps, two have none. Sometimes it the luck of the draw.
farlymac
PF McFarland
Like Raid says, I view the Zeiss bumps the same way I do scratches on a pick-up truck are character lines. It's what makes it a Zeiss. As long as they are not making the leather depart from the camera body, it's only a question of cosmetics. Good storage conditions will stabilize the growth so if the camera is afflicted when you get it, they should not get any larger. Heck, my fingers are bumpier than my Contax IIa, and I'm no where near getting them repaired.
PF
PF
peterm1
Veteran
It is all down to storage condition in essence. If there is moisture present I think you will find that the bumps can then appear where there are different metals in close contact. In moist conditions this creates a corrosive electolytic (galvanitic) reaction. It is probably also influenced by the presence of residual tannic acid in the leather covering from the tanning process. Despite the name it is not solely limited to Zeiss.
https://www.b2wphoto.com/single-post/2018-01-23-what-the-heck-is-a-zeiss-bump
(Photo sourced from the internet)
https://www.b2wphoto.com/single-post/2018-01-23-what-the-heck-is-a-zeiss-bump
(Photo sourced from the internet)
Reid
Newbie
Thoughts on Zeiss 'Bumps'
Well thank you responders and the consensus is much as I anticipated - high humidity; I will be forewarned.
I note these bumps are not limited just to Zeiss equipment having seen a Retina recently advertised with some noticeable bumps. This leads me to wonder just why my Retina, sadly long departed, managed to survive my 25 years service career in the Far East with regular relative humidity measurements in the '90's' for weeks on end, especially in spring and early summer and yet my '2C' soldiered on valiantly until the bellows rotted and rather carelessly I sold it on for spares.
Thank you contributors.
Well thank you responders and the consensus is much as I anticipated - high humidity; I will be forewarned.
I note these bumps are not limited just to Zeiss equipment having seen a Retina recently advertised with some noticeable bumps. This leads me to wonder just why my Retina, sadly long departed, managed to survive my 25 years service career in the Far East with regular relative humidity measurements in the '90's' for weeks on end, especially in spring and early summer and yet my '2C' soldiered on valiantly until the bellows rotted and rather carelessly I sold it on for spares.
Thank you contributors.
markjwyatt
Well-known
It is all down to storage condition in essence. If there is moisture present I think you will find that the bumps can then appear where there are different metals in close contact. In moist conditions this creates a corrosive electolytic (galvanitic) reaction. It is probably also influenced by the presence of residual tannic acid in the leather covering from the tanning process. Despite the name it is not solely limited to Zeiss.
https://www.b2wphoto.com/single-post/2018-01-23-what-the-heck-is-a-zeiss-bump
(Photo sourced from the internet)
Interesting. I just got a Exakta VX, and it has five Ihagee bumps
. Four of them are right where that photo shows rivets. One is an off-rivet Ihagee bump.