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05-02-2012, 07:31 AM   #16
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QuoteOriginally posted by Lowell Goudge Quote
There is a commonly used expression on the forums RTFM

Although the manual is almost useless on guiding you as to how to make adjustments, and what those adjustments really do in your photos, some of the technical data on lens and flash compatibility and options is actually quite good.
As I've been mainly shooting macro using my m42 lenses, the loss of multimode metering wasn't an issue.

I also don't think you need to READ the manual. You just need an index of all the key tables and warning notes, and those are the things you should read.

05-02-2012, 07:40 AM   #17
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QuoteOriginally posted by NaClH2O Quote
I've found the ability to control aperture from the camera body to be very efficient. I can look thru the viewfinder and change aperture to suit without having to count clicks on the aperture ring, or worse yet pulling the camera away from eye to check what aperture is set.

To me, there's not a great deal of difference between my K, M, and A lenses in terms of quality or feel, but I have to admit that I, too, like being able to control my aperture from the camera body. Sure speeds up the process.
05-02-2012, 07:58 AM   #18
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QuoteOriginally posted by audiobomber Quote
I have an Image A 28 that meters correctly at 2.8 and overexposes at smaller apertures.
One of the issues with stop-down metering in general dating clear back to the original Spotmatic. The meter has limited sensitivity and when the lens is stopped down in dim conditions, the amount of light actually reaching the sensor is outside its linear range.


Steve
05-02-2012, 08:10 AM   #19
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Touching on metering - I have noted this before, but metering sux across all brands of DSLR's. One advantage that the modern day digital camera has is the ability to show histos, using the histo one can easily use ev comp to quickly change the exposure without stressing on metering too much...

05-02-2012, 08:23 AM   #20
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QuoteOriginally posted by audiobomber Quote
I have an Image A 28 that meters correctly at 2.8 and overexposes at smaller apertures. I corrrect with EC, half a stop at f4, a stop at f8. My Sears A 135mm 2.8 macro and Pentax A*300 f4 expose correctly at all apertures. I have a fully manual Kiron 28mm 2.0 that meters correctly wide open. When I stop it down and use the Green button, it overexposes by varying amounts. To get around this, I meter wide open and count stops.
QuoteOriginally posted by stevebrot Quote
One of the issues with stop-down metering in general dating clear back to the original Spotmatic. The meter has limited sensitivity and when the lens is stopped down in dim conditions, the amount of light actually reaching the sensor is outside its linear range.

Steve
There are multiple issues here which i have , over time, addressed in some posts, but which may be worth re-addressing.

First of all, K lenses and stop down metering you need to find my curve of metering error as a function of aperture, it tells everything you need to know about the inconsistencies (or exposure error really because the problem is not inconsistent at all, but quite repeatable)

Second, and perhaps not really well discussed but many lenses have slight errors at maximum and minimum aperture. so you might see a little error due to this, My curve shows a slight error on an A50/1.2 at F1.2 because it is not really F1.2 but a little slower

third, and this is important for after market (i.e. third party lens makers) Not all A lenses have perfectly linear aperture movements. As audiobomber indicates some have increasing error as a function of aperture selected even in the A position. My tamron 28-75F2.8 is spot on wide open, where metering is calibrated, but increases by 1 full stop linearly as a function of apertue selected through the body, by the time you get to F32. This is a function of the individual camming and control of the aperture mechanism

I test my lenses for exposure linearity when I get them, just for this reason
05-02-2012, 11:33 AM   #21
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QuoteOriginally posted by Lowell Goudge Quote
There is a commonly used expression on the forums RTFM
I did read the manual, parts of it several times. Then I forgot what it said.
05-02-2012, 11:45 AM   #22
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QuoteOriginally posted by audiobomber Quote
I did read the manual, parts of it several times. Then I forgot what it said.
Then you must suffer from either CRS or CRAFT.

You can figure out what them mean
05-02-2012, 12:03 PM   #23
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QuoteOriginally posted by minahasa Quote
I love manual lenses. They're (often) cheaper, (often) better build, yet they (often) performs better than today's AF lenses.
Cheaper and better built, sure. But there are relatively few older manual lenses that actually outperform their modern equivalents, where such equivalences even exist. Lens design has not taken a step backwards. Of course, dollar for dollar, a $100 manual lens will often be a better lens than a $100 modern lens, simply because the mdoern lens won't actually be the equivalent of the older one but a deliberately downgraded lens. The actual equivalent would be considerably more expensive. So in that sense, it is true that a given dollar amount will often get you you more with older lenses - particularly with regard to primes.

QuoteQuote:
What I mean is, I uses M mode all the time, since the "A" function doesn't seem to work well anyhow, even in modes that suppose to take advantage of that Auto feature.
Not sure what you mean by that. There are no inherent issues with "A" functionality. It's certainly possible you have some particular lens that is mechanically/electrically defective - one of the downsides of buying older lenses - but all metering modes *do* work correctly with "A" lenses. Even M mode works much better with A than with M lenses, since an A lens can give you a full time meter display rather than requring a stop down operation to get a temporary meter reading, and also may support more metering modes. Not to mention the ability to have flash automation in all exposure modes.

So there is absolutely no question the functionality of an A lens greatly exceeds that of an M. But whether that increase in functionality is worth the price is another matter, of course.

05-02-2012, 12:14 PM   #24
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QuoteOriginally posted by Marc Sabatella Quote
Cheaper and better built, sure. But there are relatively few older manual lenses that actually outperform their modern equivalents, where such equivalences even exist. Lens design has not taken a step backwards. Of course, dollar for dollar, a $100 manual lens will often be a better lens than a $100 modern lens, simply because the mdoern lens won't actually be the equivalent of the older one but a deliberately downgraded lens. The actual equivalent would be considerably more expensive. So in that sense, it is true that a given dollar amount will often get you you more with older lenses - particularly with regard to primes.
but you need to consider here that over time, value for money has had great advances. Look at what it cost to purchase a lens in , say 1980, As an example take a top quality third party zoom from that era, like a vivitar series 1 70-210 F3.5 I paid $350 cdn in 1981 for my copy. today that would cost almost $900. Spending $900 on a similar lens gets you something like a sigma 70-200f2.8 faster, sharper more features and AF as well.

QuoteQuote:

Not sure what you mean by that. There are no inherent issues with "A" functionality. It's certainly possible you have some particular lens that is mechanically/electrically defective - one of the downsides of buying older lenses - but all metering modes *do* work correctly with "A" lenses. Even M mode works much better with A than with M lenses, since an A lens can give you a full time meter display rather than requring a stop down operation to get a temporary meter reading, and also may support more metering modes. Not to mention the ability to have flash automation in all exposure modes.

So there is absolutely no question the functionality of an A lens greatly exceeds that of an M. But whether that increase in functionality is worth the price is another matter, of course.
i cant figure his comment about functionality either, and the other benefit of an A lens in M mode is that the metering is calculated not actually stopped down, so the issues of stopped down metering with K lenses is non existant. the A lenses do open aperture metering with the green button.
05-02-2012, 01:42 PM   #25
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QuoteOriginally posted by Lowell Goudge Quote
This is a function of the individual camming and control of the aperture mechanism
That makes sense. When my Image A 28mm didn't meter properly, I blamed the camera, then I was surprised to find my Sears A 135 metered perfectly.
05-02-2012, 06:16 PM   #26
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What I mean by "the "A" function doesn't seem to work well" is that I can't really depends on this 'auto' feature all the time (hence the discussion about reliability of the metering above). Yes it's always nice to have the in-camera aperture setting and automation functions, but eventually I still have to adjust things more. With all-manual controls I have to do everything, there is only one driver in one vehicle, I need not to worry about decisions taken by some automation that could be not what I want.

As a non-professional photographer, I am always into price/performance issue. Yes, today's all-automatic lenses are not a fruit of downgraded inferior technology, but consequently we have to pay more for it. Here, today I can snap a SMC M 50/1.4 for about 1/4 the price of SMC A 50/1.4 and almost 1/10 the price of SMC F/FA 50/1.4. The 'automation', the convenience that we get is the real cost here, since I believe that the all-manual M could deliver similar results.
05-03-2012, 03:06 AM   #27
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I love my A50 1.7 and A50 1.4. I recently picked up a A28 2.8 and have a M28 2.8 that is looking for a new home. I have no desire to use it now that I have the 'A' version.
05-03-2012, 04:05 AM   #28
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QuoteOriginally posted by minahasa Quote
What I mean by "the "A" function doesn't seem to work well" is that I can't really depends on this 'auto' feature all the time (hence the discussion about reliability of the metering above). Yes it's always nice to have the in-camera aperture setting and automation functions, but eventually I still have to adjust things more. With all-manual controls I have to do everything, there is only one driver in one vehicle, I need not to worry about decisions taken by some automation that could be not what I want.

As a non-professional photographer, I am always into price/performance issue. Yes, today's all-automatic lenses are not a fruit of downgraded inferior technology, but consequently we have to pay more for it. Here, today I can snap a SMC M 50/1.4 for about 1/4 the price of SMC A 50/1.4 and almost 1/10 the price of SMC F/FA 50/1.4. The 'automation', the convenience that we get is the real cost here, since I believe that the all-manual M could deliver similar results.
There should be no difference between metering on A lenses and any new autofocus lens. It should meter correctly, or with the minor exposure errors I have described, I.e. max and min apertures not exact, and /or slight but consistent exposure drift away from perfect as you stop down. None of these issues aree any different today than they were 30 years ago, and even modern lenses have errors. If you have extreme errors with a lens then the lens is defective, nothing else. KA mount lenses are worth the premium, because you can use every exposure mode, and have flash. It is nothing to do with convenience, they are functionally better. Moving to AF is a different discussion. I like my MF primes, not so much because they are better or not, but they force me to slow down. Like you photography is a hobby, and for me a form of relaxation, I go full manual when I am on my time, but there are times when I am shooting but NOT on my time, and for those times I'll tale all the automation I can get
05-03-2012, 05:23 AM   #29
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Lowell, that's exactly my point. If those "A" lenses are just AF lenses without AF function, and metering with those (although with added ease of use) just added another thing to worry because we know that it will go meter by itself but there's no guarantee it will meter correct, then why not do it all by our self? The convenience -ease of use- we get from "A" lenses is, for me, not really enough to justify the added price and for faster-action events I rather grab an all-automatic lens instead.
05-03-2012, 05:45 AM   #30
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Does not the EXIF data misrepresent with A lenses when taken off A? No effect on images, but lousy for feedback later.. and a crummy conversation starter when the first question someone asks me is for exposure data . When I take my Sigma macro off the A setting, every image records max aperture.

That's all I got re. A-mode issues.
I love my all-manual Rikenons! Just picked up the trifecta lens so I have 28, 35-70, 70-150

I shouldn't read here before 6AM.. RTFM had me rolling on the floor but I couldn't remember why!

Last edited by jimr-pdx; 05-03-2012 at 06:03 AM.
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