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06/18/2006 10:43:44 AM · #1 |
Is this lens for an older SLR film camera? I have one that is similar and it fits on a 58mm adapter and works great on my canon S2 but im wondering what it was designed for?
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06/18/2006 10:45:27 AM · #2 |
Looks like a telephoto adaptor designed to fit over another lens to make it "longer", an old one...
R.
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06/18/2006 10:58:31 AM · #3 |
it says telephoto 1:4... does that make it a 4x Teleconverter?
Wow!
Did you try to stick it in front of your camera to see what effect it had?
Flip it backwards too. |
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06/18/2006 08:07:30 PM · #4 |
It looks to be an old screw on teleconverter.
During the 60's and 70's fixed lens rangefinders with a fast normal lens fitted were very popular. Often a manufacturer would offer a wide angle and telephoto accessory lens much like the screw on lenses offered today for P&S digital cameras. This particular one looks to have been made by Yashica for their cameras. These lenses, as a general rule, did not tend to be very high quality by modern standards and were fairly limited. The telephoto would be about a 1.5x while the wide angle would be a .8x.
The numbers on the side are there to help the photographer adjust the focus with the accessory lens in place as it would shift the focus point and the rangefinder would no longer be accurate.
The 1:4 probably refers to macro reproduction as it would also act as a macro filter, though a rangfinder is a pretty poor design to try to shoot macro shots with.
You can certainly use it on your S2 without a problem, but my guess would be that even the less expensive modern screw on teleconverters would perform at least as good and probably better. |
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06/19/2006 12:49:58 PM · #5 |
| My guess would be that it is a teleconverter designed to fit *behind* the main lens. Yashica was one of the many brands that used screw mount lenses in their early models. The teleconverters for these cameras screwed into the camera mount, then the taking lens was installed in front of them. I've never seen one that goes to 4 times, most doubled the focal length. This looks similar to a teleconverter I had for my Mamaya Sekor DTL 500, probably around a 1960s model. |
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06/19/2006 10:36:39 PM · #6 |
The numbers on the side is what throws me off. Most converters dont have these markings all around them so i wondered if it was an SLR lens. Nothing moves on it so im a little confused how you would use the numbers when nothing turns on the lens.
Ive found a few older converters that work as good as the $100. teleconverter designed for this camera most cost about $10. or less. I got the canon to compair and what a waste of money. |
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06/20/2006 10:23:07 PM · #7 |
Originally posted by BowerR64:
The numbers on the side is what throws me off. Most converters dont have these markings all around them so i wondered if it was an SLR lens. Nothing moves on it so im a little confused how you would use the numbers when nothing turns on the lens.
Ive found a few older converters that work as good as the $100. teleconverter designed for this camera most cost about $10. or less. I got the canon to compair and what a waste of money. |
The numbers are a scale for use with the camera body.
When you focus with the rangefinder there will be an indicator on the body or lens of the distance focused to. In order to be in focus with the teleconverter you would need to readjust the focus in line with the scale on the teleconverter. With a rangefinder you are not focusing through the lens. It is calibrated specifically to the lens built into the camera and when you modify the focal length and optics by adding the teleconverter it will no longer be accurate and focus has to be manually adjusted using the scale provided on the teleconverter.
With that lens and the camera it was made for, if the rangefinder focused at the white number, for example 10 ft, you would need to change the focus to the red number, in this case 7 ft, to be in focus with the teleconverter in place. |
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06/21/2006 04:29:55 PM · #8 |
But look at the end of the lens where the threads are. See how it tapers to a point? that doesnt look like the typical teleconverter. It looks more like a taper on the SLR lenses that fit up inside the body.
What does the 1:4 mean?
Thanks for your help, i have a set that doesnt use threads it has a twist and click type attachment |
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06/21/2006 10:12:59 PM · #9 |
Originally posted by BowerR64:
But look at the end of the lens where the threads are. See how it tapers to a point? that doesnt look like the typical teleconverter. It looks more like a taper on the SLR lenses that fit up inside the body.
What does the 1:4 mean?
Thanks for your help, i have a set that doesnt use threads it has a twist and click type attachment |
I'm only guessing about the reason for the rear design, but I would assume it was designed to be as close to the front element as possible to avoid any vignetting. Since it would have been meant for a specific lens they would have been able to make the tolerances fairly tight and know they wouldn't rub the front element of the lens.
As for the 1:4, it would seem to refer to a macro reproduction ratio. If a lens has a reproduction ratio of 1:1 then the image on the film would be exactly the same size as in life. A 1:4 ratio would mean that the image would be 1/4 the size of the real life object. So, when this auxiliary lens was attached the camera could get close enough to a subject to record it at 1/4 size on the film frame. |
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