6x7 Eyepiece Correction Lenses
Hello, Can anyone help me to decide if I would benefit from a correction lens in my 6x7 eyepiece? (It's a 6x7 MLU with plain prism). On my LX I have the FA-1 set to mid-range, so assuming a linear scale that's about -0.75 diopters. This is the viewing experience that I would like to duplicate on the 6x7. The 6x7, bought used, came with what seems to be a piece of flat glass in the eyepiece. Is this the standard eyepiece that gives the overall -1D listed in the manual? Can I compare the -0.75D value from the LX with the -1D of the 6x7? Or, should I read the LX setting as some built in value minus a further 0.75? If my two viewfinders are -0.75 and -1.0, then the difference is only 0.25. That doesn't seem much. Should I expect to feel that the 6x7 needs correction if it is only out by that far? Or, is the overall diopter of the LX something larger, say -1.75D? In that case I might expect a -1D correction to get me closer than I am at present. Is it worth guessing at an appropriate correction, or do I need to take my camera to the optician and actually try some lenses? Thanks in advance for any suggestions. Steve.
Re: 6x7 Eyepiece Correction Lenses
On Fri Apr 15 16:32 , 'William Robb' [EMAIL PROTECTED] sent: Find out from your optometrist what your glasses correction is, and try to find a diopter in the same range. Thanks Bill. I will pay them a visit tomorrow and see what they can do. I'm sure they'll be able to find me something that works. I am, however, an incorrigible nerd, so I may not be completely happy until I understand the numbers too. Steve.
RE: S-Car-Go
John Francis wrote: I saw a 2CV6 on the roads out here just a week or so ago. I don't know just which V6 it had under the hood, but it certainly wasn't the original 602cc as supplied - it had a pretty good turn of acceleration. The 2CV is light, and the 602cc flat twin is fairly torquey. It's unlikely ever to be mistaken for a performance car, but it can accelerate better than a lot of people expect. The gap between 1st and 2nd gears is awkward, and it begins to struggle before 60mph, so 0-60 figures timings (about 32 seconds, IIRC) aren't a great representation of what it can do between 10 and 40. I sold mine last year. I miss it. A fairly common modification is to fit one of the flat fours from the Citroen GS. They give about 60 bhp before tweaking. I remember struggling to manage 45mph into a headwind on the M1 in my 2CV, and being overtaken by another 2CV going a good 15-20mph faster than I was. I was furious. I suspect that was a four cylinder modification of some sort. Or for something a little more extreme, how about this: http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItemitem=4520722747 Steve. ** This e-mail has been sent from Imagination Technologies Limited. PowerVR, Metagence, Ensigma and PURE Digital are divisions of Imagination Technologies Limited. The information contained in this e-mail, including any attachment, is confidential and may be legally privileged. It is intended solely for the addressee(s) and access to this e-mail by anyone else is unauthorised. If you are not the intended recipient, any disclosure, copying or distribution or use of the information contained in this e-mail, is prohibited and may be unlawful. If you have received this e-mail in error, please notify the sender by return e-mail and then delete it from your system. Internet communications cannot be guaranteed to be secure, error or virus-free. The sender does not accept liability for any errors or omissions which arise as a result. Any views expressed in this message are those of the author, except where the author specifies and, with authority, states them to be the views of Imagination Technologies Limited.
RE: OT: The Older Man - was: PESO: Here's my Mannequin
Didn't one of the French carmakers have a prototype of a little urban car (if it ever went into production, it certainly never made it to North America) called the S-Car-Go? I'm thinking Citroen, or maybe Peugeot... Nissan did the S-Cargo. A little van from the early 90s with a hint of 2CV in the styling: http://images.google.com/images?q=s-cargo I think they were produced in limited numbers and only ever sold in Japan. I have seen one or two in the UK, which must have been specially imported. The Figaro was a little retro-styled Nissan from the same period which occasionally turns up in the UK too: http://images.google.com/images?q=nissan%20figaro ** This e-mail has been sent from Imagination Technologies Limited. PowerVR, Metagence, Ensigma and PURE Digital are divisions of Imagination Technologies Limited. The information contained in this e-mail, including any attachment, is confidential and may be legally privileged. It is intended solely for the addressee(s) and access to this e-mail by anyone else is unauthorised. If you are not the intended recipient, any disclosure, copying or distribution or use of the information contained in this e-mail, is prohibited and may be unlawful. If you have received this e-mail in error, please notify the sender by return e-mail and then delete it from your system. Internet communications cannot be guaranteed to be secure, error or virus-free. The sender does not accept liability for any errors or omissions which arise as a result. Any views expressed in this message are those of the author, except where the author specifies and, with authority, states them to be the views of Imagination Technologies Limited.
RE: Pentax News
Cotty [mailto:[EMAIL PROTECTED] wrote: The only way would be to mount the 35mm lens *inside* the 645 lens throat, so that the distance from the back of the K mount lens to the 645D's sensor was 45.46mm - but sadly wew then have the problem of the 645D's mirror hitting the whole kit and caboodle. Perhaps what we need is not lens adapters but completely interchangable mirror boxes. A nice little compact one for 35mm lenses, and a big sticky-out one with a correspondingly larger mirror for 645 lenses. And we still haven't even begun to consider the fact that the image circle would be smaller than that produced by a 645 lens. Joe suggested that the camera could crop automatically when a 35mm lens is detected. Perhaps the sensors could also be made modular, so we could have a choice between 35mm full frame or sub-645 according to budget. Viewfinders would be interchangable too, of course. Sorry mate, I love all this shit. Me too, but only because I haven't stopped to think about how much all the above might cost... Steve.
RE: PUG's Blue Notes
Henk Terhell wrote: Lemon: perhaps blue lemons are almost easier made by GMO techniques than painted so smoothly like this one. Looks to be a good shot (with the right caption) for a magazine advertisement. Thanks Henk. I think the best way to get a similar effect would be to genetically engineer a version of myself that is competent in Photoshop, and do the colour change there. I'm not entirely happy with the way that the paint has smoothed out the texture of the lemon skin. It was quite fun to do though. I may have been the first person to ask my local paint emporium to recommend a primer suitable for citrus. Tom C asked how I masked the stem bit (calyx?). I just pulled it off, and glued it back on after the paint had dried. Thanks to everyone who commented on the PUG. Steve.
Re: OTF metering question
On Fri, 9 Jul 2004 12:08 , 'Peter Loveday' [EMAIL PROTECTED] sent: On the LX at least, OTF metering only works at slower than X speed anyway. Ah, I didn't realise that. I can see that the ability to respond to light changes during the exposure (i.e. the integrating aspect) is much reduced at speeds around and above the X speed. I had always assumed that the metering was as I described, using the OTF cell to time the release of the second shutter curtain. Doing it that way would work just as well at speeds higher or lower than X, as far as I can see. Are you suggesting that there is some other mechanism used for speeds faster than X? Storing the pre-exposure meter reading, like a camera with the meter in the prism, perhaps? I'd be very interested to learn how this works. Steve.
Re: OTF metering question
Steve Jolly [EMAIL PROTECTED] wrote: Indeedy. Metering with the mirror locked up is nice, but surely the nicest feature of OTF metering is that it can respond to changes of light mid-exposure, for which purpose a pattern printed on the shutter is not required. As far as I can tell, the necessary sensors and electronics to perform this kind of OTF metering are built-in to *all* modern Pentax cameras, not just the LX. Despite this, the LX is the only Pentax camera that can do it, and I'd be interested to know why. One thing that occurs to me is that the LX uses a relatively complex half silvered mirror, and a secondary mirror behind the main mirror, in order to get light onto the metering cell while the mirror is down. OTF metering while the mirror is up seems easy in comparison. Isn't the pattern on the shutter still required for the type of metering that you describe? At speeds higher than the sync speed the meter needs to decide to release the second curtain while the first is still moving. At a very high speed, where the slit is narrow, most of the patterned shutter will still be visible to the meter cell at that moment. I wonder if the different natures of flash and ambient light also makes a difference? Flash is always fairly bright, while the LX can also handle extremely low light levels with the same meter. I suspect that the LX meter requires a greater degree of dynamic range and linearity than most TTL flash meters were designed for, even if the basic integrating principle is the same. Steve.
Re: OTF metering question
On Thu, 08 Jul 2004 21:22 , mike wilson [EMAIL PROTECTED] sent: I read recently that the LX _mirror_ is SMCed to the tune of 15 coats. Anyone know the truth of this? I read the same thing at http://www.mir.com.my/rb/photography/hardwares/classics/pentaxlx/ If true, does this mean that we can put cigarettes out on it? I've often read that the silvering is fragile, and that SLR mirrors should be cleaned with great care, if at all. It would be nice to learn that this is another respect in which the LX is better than other cameras, but I'm not sure that I want to be the first to test it. Steve.
RE: *ist D reaches Tyneside!!!
Mike Wilson wrote: p.s. I couldn't think of anything for the running water side but I suppose the fact that the river Tyne has gone from something you would want to keep well upwind of on a sunny day, to England's premier salmon river might do it.. The electricity at Cragside was generated with running water, from reservoirs in the grounds, and using turbines designed by Armstrong. The house also boasted hot and cold running water, and a hydraulically powered passenger lift and other bits of equipment. Well worth a visit. http://www.nationaltrust.org.uk/traveltrade/propertydetails.cfm?property_id =195 I used to live in Wylam, where Hedley, Hackworth and Stephenson did so much pioneering railway stuff. It was also the home of Charles Parsons, the inventor of the steam turbine, and designer of 'Turbinia'. Steve.
RE: Optio S flash
Bill Owens wrote: Apparently the Optio S uses a flash system similar to the MZ-S. In normal flash mode there are 2 quick flashed and in red eye reduction there are three. Has Pentax been able to get a flash sensor inside something this small? I don't know how the MZ-S flash works, but I can confirm the number of flashes from the Optio S. Is it using the first flash to meter the scene, and the second (with duration modified appropriately) to make the exposure? I wonder if a seperate flash sensor is required. Can it not just use the CCD? This weekend I used my Optio S to take some flash pictures in dim light, and I have to say that I was very disappointed with the results. Nearly everything was badly underexposed, to the point where I don't expect it to be salvagable. I had checked the flash range specs in the manual, and I knew I was working right at the limit (perhaps a little bit beyond it :-). I think my mistake was to leave the camera set on 'Auto' ISO: While the flash ranges are specified at 200, it seems that the camera saw fit to choose 100 ISO for these pictures. I would have hoped to have spotted the problem straight away on the LCD, but it seems that this can give a rather optimistic interpretation of underexposed images. The histograms do show what was going on, but I wasn't looking at them. I will, next time. I think I know what I need to do to avoid these problems next time. (It may involve an LX and fast film). Any other tips, or GIMP/Photoshop recovery techniques, will be gratefully received. Unfortunately the event, a christening, is unlikely to be repeated. Steve.
LX at night.
Hello, I wanted to experiment with the low light capabilities of my recently acquired LX, so last week I went out on a clear night and tried to take photographs. The results were a little disappointing, and I'm hoping that somebody will be able to explain why. I used the LX in 'automatic' mode with MLU, an SMC-M 28/2.8, tripod and cable release, and XP2 Super rated at 200 ISO. When the scenes contained some artificial light, such as car headlamps, streetlights, etc., the LX got the exposures just about right. e.g. 10 sec at f/8. I bracketed +/- 1 and 2 stops, and normally found that the +1 or +2 images gave negatives that scanned fairly well. When I tried some much darker scenes, the results were less good. I tried pointing the camera into a starlit field, fairly dark, but trees, fences, etc., were quite easily visible to the eye. The LX chose exposures of roughly 30 sec at f/5.6. Rather short, I think, compared to some of the suggested exposure tables that I've seen, and sure enough, the negatives are so badly underexposed as to be useless. I realise that it might be better to shoot at dusk rather than in near complete darkness. One of my problems was that it was almost impossible to compose shots in the dark, so even the photos that were properly exposed weren't very good. :-) At the moment though, I'm curious about why the exposure seemed to be so wrong with the starlit landscapes. The exposures that the LX was choosing seemed to suggest that it was within the metering range described in the user manual, yet the negatives are almost completely transparent. Is it unrealistic to expect these sorts of shots to work in 'automatic'? I was hoping that the LX's super-meter would take some of guesswork out of shots like this. Thanks for any suggestions and advice, Steve.
RE: Fill-in Flash with AF200T
The only other thing I can draw is gorillas. Will they do? Good man. Dan Scott Here you are then. My apologies in advance. http://www.morphet.org.uk/gorillas.gif Steve.
RE: LX Erratic Shutter (Illuminati)
What we need to know: Does the first (and more major) 'fault' happen only at 3200 1600 - I've had some at 800 and slower, so I guess I've answered that one. This is my first post to the list, but I've been lurking for a few weeks. Hello! I bought an LX recently, and I'm delighted with it. I gave it a good workout when it arrived, and I think I noticed the same quirk. I was testing at 200 and 400 ISO speed, with and without film loaded. I have an old style shutter. Without film, on auto, and with an indicated shutter speed of 1-2 seconds, (the actual shutter speed was rather longer, as expected), about 1 shot in 10 was noticably too fast ( 1/30th, I think). What I found surprising was that if I set the same shutter speeds manually I get the same result. I don't know how the LX regulates the slow manual speeds, but I can't imagine that the meter is very much involved. I spoke to someone at Asahi Photo (Wembley, UK). I'm afraid I forget his name, but he was obviously very knowledgable and extremely helpful. He explained that shooting without film was prone to confuse the LX electronics, and that the problem would disappear if I loaded the camera. He didn't seem surprised to hear that the manual speeds were also affected, but didn't really explain why. With film loaded, the frequency of the fault was much reduced, but not eliminated. It was about once in 20 or 30 shots. I consider this acceptably infrequent for my requirements, and I'm not aware of it having affected a real photo yet. I'd certainly be interested to know if the same thing was as likely to occur at higher speeds though. I hope my observations have added something useful. Steve Morphet Herts, UK.
