Gabriel M.A.
My Red Dot Glows For You
:bang: :bang: :bang:
That's right...me so dubm ---- I completely forgot about that. I should be looking at the camera when I think out loud from now on. Well, there goes that idea.
That's right...me so dubm ---- I completely forgot about that. I should be looking at the camera when I think out loud from now on. Well, there goes that idea.
ErnestoJL
Well-known
John:
Of course, there is a limitation in terms of maximum shutter speed, but the idea behind all this discussion is if it´s possible to modify the original electronic design in such a way to admit working with higher ISO ratings.
There is no "program" in those cameras (I´m limited to YE 35 XYZ) just a simple analog circuitry very well designed in terms of economy of components but with some tricky array of sliding switches inside (POD and related elements).
As simple RC circuitry, which charges to "read" the lighting and discharges to control the shutter, it should be possible to modify it, however it won´t be an easy job.
The question if the CdS cell response is linear or log, is very interesting one as the circuit itself doesn´t behave in a linear manner as long as the charging curve of a capacitor though a fixed resistor isn´t also linear. And as far as I see there is no constant current supply in this design...
Perhaps what Yashica engineers did was to use the CdS cell in a range of lighting where it is more or less linear, and select the switching points of the transistor array to lie within those limits. Then, the circuit becomes almost linear within a limited range of light and voltage. Then ... the two resistors one in series and the other one in paralell.
In fact I´m not eager to modify any of my cameras in such a way, unless having enough time to experiment it, and having also several of them (to have spares) as the modifications may lead Us to the resistor array inside the shutter. It would be nice, but I won´t face the risk of turning a fine camera into junk. Any way, you´re right, life is too short...
Meanwhile, where did you get the YE 35 service manuals? may I PM you?
Thanks for a very interesting discussion about one of those "what if...?" that everybody´s live may have.
Regards
Ernesto.
Of course, there is a limitation in terms of maximum shutter speed, but the idea behind all this discussion is if it´s possible to modify the original electronic design in such a way to admit working with higher ISO ratings.
There is no "program" in those cameras (I´m limited to YE 35 XYZ) just a simple analog circuitry very well designed in terms of economy of components but with some tricky array of sliding switches inside (POD and related elements).
As simple RC circuitry, which charges to "read" the lighting and discharges to control the shutter, it should be possible to modify it, however it won´t be an easy job.
The question if the CdS cell response is linear or log, is very interesting one as the circuit itself doesn´t behave in a linear manner as long as the charging curve of a capacitor though a fixed resistor isn´t also linear. And as far as I see there is no constant current supply in this design...
Perhaps what Yashica engineers did was to use the CdS cell in a range of lighting where it is more or less linear, and select the switching points of the transistor array to lie within those limits. Then, the circuit becomes almost linear within a limited range of light and voltage. Then ... the two resistors one in series and the other one in paralell.
In fact I´m not eager to modify any of my cameras in such a way, unless having enough time to experiment it, and having also several of them (to have spares) as the modifications may lead Us to the resistor array inside the shutter. It would be nice, but I won´t face the risk of turning a fine camera into junk. Any way, you´re right, life is too short...
Meanwhile, where did you get the YE 35 service manuals? may I PM you?
Thanks for a very interesting discussion about one of those "what if...?" that everybody´s live may have.
Regards
Ernesto.
phall715
Newbie
A tangent: GT doesn't go to asa1000?
A tangent: GT doesn't go to asa1000?
Hi,
I'm just puzzled a bit here (and I'm coming in late to the discussion, I know) but I thought that GS/GT's went to 1000 and that that was one of the improvements over the original G? Or was it a mid-model change? Or have I got the model naming a bit wrong?
Just curious. I've got a GS and it goes to 1000.
Cheers,
Phil.
A tangent: GT doesn't go to asa1000?
Hi,
I'm just puzzled a bit here (and I'm coming in late to the discussion, I know) but I thought that GS/GT's went to 1000 and that that was one of the improvements over the original G? Or was it a mid-model change? Or have I got the model naming a bit wrong?
Just curious. I've got a GS and it goes to 1000.
Cheers,
Phil.
Gabriel M.A.
My Red Dot Glows For You
Apparently there are some earlier bodies that only go up to ISO 500. I have two of them. I have not been researching this actively for almost three weeks now, but Winter is around the corner, and ISO 800 will be a must (for me) in the evening.
Still any more input welcome...
Still any more input welcome...
ErnestoJL
Well-known
AFAICR, when the YE 35 was introduced to Argentine market (1969), there was only one model, the original satin chrome finished. In 1972 the black GT was introduced also having its upper limit iat ISO 500. Later in 1975/76, other models were introduced and they did reach ISO 1000 (I guess they were the GS/GSN and the GTN).
Probably Yashica´s distribution department concentrated in some markets of better economic potential then the change from ISO 500 to ISO 1000 took place at different times in different places. The local secondhand market is mostly of earlier YE35 models.
Ernesto
Probably Yashica´s distribution department concentrated in some markets of better economic potential then the change from ISO 500 to ISO 1000 took place at different times in different places. The local secondhand market is mostly of earlier YE35 models.
Ernesto
chenick
Nick's my name!
ErnestoJL said:
I nearly bought a GSN in the market in San Telmo a few months ago, but I couldn't justify it as I have a GTN already. But now I wish I had bought it, just as a spare (although I didn't even ask the price!) Maybe next time...
-Nick
ErnestoJL
Well-known
Oooohhhh.....San Telmo....that´s the worst place to buy a secondhand camera in Buenos Aires... prices are for tourists, not for photographers!
Think of this, I found a Metraphot in excellent (working) condition for USD 25 in another flea market, but the same in San Telmo (a non working one) will cost you at least USD 100, just because it was made thinking of Leica... and is a collectible item.
My GSN was priced USD16, and the GT was only USD 6 ...
Ernesto
Think of this, I found a Metraphot in excellent (working) condition for USD 25 in another flea market, but the same in San Telmo (a non working one) will cost you at least USD 100, just because it was made thinking of Leica... and is a collectible item.
My GSN was priced USD16, and the GT was only USD 6 ...
Ernesto
chenick
Nick's my name!
ErnestoJL said:
Hehe, well I was going to offer 30 pesos, just on the off chance
Saw nothing else of interest there (quite a few old cameras, but not really any RFs)
Then I saw a several Canons (VIIs and VTs) in Tacuari (a la altura de Av. de Mayo) but they wanted US$600 each. No thanks! Didn't even ask about the Leica M1 (non RF)
Where was the other market?
Saludos
Nick
ErnestoJL
Well-known
chenick said:Hehe, well I was going to offer 30 pesos, just on the off chance
Saw nothing else of interest there (quite a few old cameras, but not really any RFs)
Then I saw a several Canons (VIIs and VTs) in Tacuari (a la altura de Av. de Mayo) but they wanted US$600 each. No thanks! Didn't even ask about the Leica M1 (non RF)
Where was the other market?
Saludos
Nick
Well to be honest, there is no such "other market". What in fact exists is several stores for secondhand cameras that do not look specially for collectors but users, where prices are reasonable (think of -10 to -35% from intl. prices for such goods). There are a few of them close to the downtown, some other "flea markets" are in some squares in the city (not downtown) and outside the city limits only on week ends. I bought the Metraphot in a small town about 25 km away from BUE on sunday at 2 PM, surely not within any tourist route!!!
The store you mention, Polanco Foto Cine, is a very old one, the prices are international prices, and the owner knows very good what is he selling, however he gives usually a short term (3 months warranty), besides this is something you won´t obtain from any San Telmo dealer.
Next time, just mail me if I can be of help.
Good luck
Ernesto