daveh
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Post by daveh on Dec 17, 2016 19:27:31 GMT -5
Photo 1 - set to f22 Photo 2 - set to f2.8 Photo 3 - as 2, but focus altered to emphasise the auto diaphragm lever
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daveh
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Post by daveh on Dec 17, 2016 19:10:28 GMT -5
Johnbear, I'm sure you're right about the window covering the scale. The earliest lenses I have with that are the Pentax-F which date from the early '80s. Of course some lens manufacturer could have used them earlier, but it would seem to be that era, around the 1980s, when they became more commonplace.
Conan, it would appear to get interesting here. I was looking at your photo and comparing it to my lens. The auto-diaphragm lever (to the mid-left of the lens as we look at it0 in your photo is in the closed position i.e. the blades are at the f22 position - at least they are in my lens - and yet the scale is set to f2.8. When I set my lens to f2.8 the lever is at the very back of the slot.
additionally the the lever that connects with the metering linkage is at the very front of its slot (i.e in the same position as yours) when it is set at f22 (rather than the 2.8 yours is set at).
From what we have so far it would appear that the numbering on yours is the wrong way round, but everything else is the same, that is to say it would operate perfectly but when set at f22 the lens is actually operating at f2.8 (and so on through the scale - f16=f4, f11=f5.6 and f8=f8).
Anyway, here are the photos referred to above - at least they would be if I hadn't used "quick reply". I'll post this as is then use "reply" to do the photos.
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daveh
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Post by daveh on Dec 16, 2016 15:25:38 GMT -5
I have a couple of non-Topcon lenses. A wide angle and a 200mm. Neither of these has any similarity to the Topcon made lenses other than the mount. I would have to find them to check which way the f-stop (and focusing for that matter) runs.
There always seems to be a law about brand lenses: if they weren't made by the company itself, then they were made by Cosina.
I can't think of having seen a Topcon lens with a window covering the scale but then, to be honest I haven't really looked at what lenses have been available since I was using the SuperD in the 1970s. Well, I've not really been any help. What would be interesting, though would be to compare my lens fully with yours to see exactly how they compare e.g. Colour of lettering, typeface used etc. If I get round to it I post some more photos of my lens
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daveh
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Post by daveh on Dec 15, 2016 8:19:06 GMT -5
I was in a bit of rush posting this morning. I realise that I have got the lenses the wrong way round. Outwardly my 35/2.8 is as the lens on the left of your photo, as well ok at it. All the lenses I have have th e 2.8 (or whatever) as per the silver lens of your photos. I can't lay my hands on the 58/1.8 at the moment but I'm sure that is the same as the other three.
Your black lens above appears to have a window over the distance scale. None of my lenses have this.
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daveh
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Post by daveh on Dec 15, 2016 3:57:24 GMT -5
I've got a 35/2.8 and mine goes in the same direction as the other RE AUTO TOPCORs that I have. Moreover it is physically longer with possibly less diameter than the lens you have.
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daveh
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Post by daveh on Dec 12, 2016 21:02:23 GMT -5
stop-down lever on LTL/MTL next to shutter button LLC stop down button on lens - pretty impossible to see in this photo but its by the silver square closest to the base of the shutter release. view of Oreston lens to show stop-down button Photos done in a bit of a hurry so not the best sorry. I haven't a battery to test it out, besides which the aperture blades are sticking - well it hasn't been used for 30+ years.
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daveh
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Post by daveh on Dec 12, 2016 20:14:10 GMT -5
It's a long time since I've used my LLC.
The LTL has a stop down lever on the body. If I remember correctly on the LLC lenses there was a stop-down button on the lens itself and this has to be pressed to measure the exposure using stop-down (as there isn't a lever on the body - at least not that I can recall). I think that the half-press on the shutter button turns the metering on but doesn't stop down the lens. That is to say the shutter needs to be half-pressed at the same time as the lens stop-down button is pressed.(Mind you I can't recall using stop down metering as open aperture seemed so much easier all round.)
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daveh
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Post by daveh on Aug 8, 2016 18:08:49 GMT -5
The answer is, of course, neither. However I did buy a Topcon Super D about that time: open aperture metering retained whatever viewfinder or screen is in place rather than one of those bulky and limited photomic heads
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daveh
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Post by daveh on Jul 25, 2016 16:36:02 GMT -5
The problem is not so much holding a 135mm on a converter but: 1) there is a penalty in the exposure - a 2X converter loses 2 stops 2) the lens is now effectively a 270mm so there is a need to ensure the shutter speed is fast enough for that.
In effect, then, there is a three stop penalty: two that the converter uses up and another to increase the shutter speed.
It's not just a case of decreasing the definition with a converter, but also increasing the aberrations. This is twofold: magnifying the aberrations of the original lens and secondary introducing its own.
Digital has the added advantage of being able to increase the "film" speed on the fly.
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daveh
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Post by daveh on Jul 23, 2016 3:44:54 GMT -5
A camera is a tool to do job. Some look better or work better than others. Much is down to personal preference and as a result some things are promoted while others are dismissed without real reason.
Most camera advances go through a developmental "must-have" phase, which for whatever reason doesn't fully deliver. Certainly the biggest problem with early electronics was the type of batteries available. Having at least mechanical shutter speed included was always a good idea.
With current configurations of batteries and low power drain cameras the electronic age has become..., well, it's become of age. I wonder though how far off anyone is from making a solar powered camera which never needs an external method to charge its system.
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daveh
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Post by daveh on Jul 23, 2016 3:23:35 GMT -5
I went to Antwerp when I was about 11. I don't recall much about it other than some wonderful buildings in (what I would say) is the typical style for that region of Europe.
I have been to Belgium a few times, though not enough in all honesty. Thanks for posting.
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daveh
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Post by daveh on Jul 23, 2016 3:10:47 GMT -5
Did you consider buying it? Did the proprietor know what he was selling, or had he just priced it at £220 as it was old?
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daveh
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Post by daveh on Jul 23, 2016 3:06:14 GMT -5
Does anyone buy equipment at full price?
Forty years or so back we used to have the Resale Price Index in the UK: items were sold at the set price. When that was abolished prices tumbled. However, even at the new cut price, we paid something like 25% more than the item was selling for in the USA. The internet and the global market have forced sellers to have competitive pricing. That said, there is always the item that is offered, on such as eBay, at a considerably higher price than seems "reasonable". Then we get the companies that offer everything at prices that seem too good to be true. The trouble is that they often are too good to be true.
My answer would be that I will pay what I consider to be a fair price for the item being offered. That is unlikely to be full price but also unlikely to be the cheapest either.
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daveh
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Post by daveh on Jul 23, 2016 2:46:04 GMT -5
I don't know, but I suppose there is always a chance that Tamron don't actually make them and another company do the manufacturing for them: is it perhaps another case of step forward Cosina, or some unknown Chinese company. The Cosina Files on here gives an idea of the not inconsiderable spectrum of Cosina manufactured photographic equipment.
I occasionally use a matched Canon 1.4 multiplier on my 70-200 f4L lens. There is almost no degradation of the image, unlike the older (and considerably cheaper) tele-converters from the 1970s.
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daveh
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Post by daveh on Jun 23, 2016 16:52:08 GMT -5
May I just pose a possible problem with these tests? Each lens type will have to have an adaptor. What's more to obtain infinity focussing many will have to have a supplementary lens. How do we know that the test results are the result of the lens alone?
(What needs to be done is to test each lens on an original camera, using film if necessary and then comparing results with what comes out of this test for the same lens. Unfortunately trying to approach things too scientifically results in a ridiculous amount of data. Even if you have the time to collect all the data it then has to be interpreted meaningfully. It should, of course, all be done "double blind" to prevent inherent bias for or against any particular lens or its manufacturer.)
Good stuff, though: well done for setting it up.
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