I have been researching photography-related issues to improve my photographs. At the end of this (rather long) page is a list of useful links. The rest contains "reprints" of posts I have made to the Minolta list on Yahoo groups. I hope these somewhat random discourses are helpful to you, the reader, in improving your photography as well.

Topics:

Thoughts on Digital vs. Film
Can you use Minolta manual focus lenses on an autofocus body? I have heard that there are adaptors.
Sigma-Maxxum incompatibilities?
3rd Party wide-angles for the Minolta manual system
On the various Sigma 28-105mm zoom lens.
Is the 24mm f/2.8 Sigma lens really better than the Minolta version?
What is the best lens?
Best AF prime lenses for wide angle coverage?
How good is Minolta's AF 85mm f/1.4?
Why can't I get a lens that shows me the world as it really is? My eye is a lens and it has no problems!
What is Bokeh?
How does the proformance (image quality and AF speed) of the classic maxxum 70-210 f/4 compare with an off brand (ie. Tamron) 70-300 f/4-5.6?
Photographing buildings
Upgrade the body or the lens?
Upgradeing the Maxxum 70-210 f/4
Himatic Rangefinders
The SRT Battery problem

Thoughts on Digital vs. Film
In hearing many things about "how much detail is enough?" I find a certain irony in hearing that digital is "good enough" and top quality film has "too much extraneous information" from the same people (not necessarily on this list) who would rather die than be caught with a third-party lens on their camera. I mean, why buy a lens that will resolve to 120 lines per mm if the medium that you are capturing to will not resolve 1/10 of that? What is the advantage of a Minolta G prime lens over a Cosina 28-300 zoom if the medium being recorded is a CCD array, complet with noise, at 1024x1200 pixels? I exaggerate a bit, but it makes you wonder...
I have read (I forget the source) that the maximum amount of data on the most fine grained film that a scanner can caputure is about 6000 dpi. Beyond that you are resolving grain. Some exceptions are good to over twice that (12,000dpi for Technical Pan). This would result in files of 600 MB per image for most films, and 2.4 GB file for one Technical Pan frame. So when you shoot a roll of 36 exposures of Kodak Gold, you have recorded 21.6 Gigabytes of potentially digital information. Leaving aside all questions of how useful this might be, suffice it to say that digital cameras have a long way to go before they match the potential inherent in film. If you have ever shot 20 rolls of film in one day, ask yourself where 432 Gigabytes (almost half a terabyte) will go in your camera bag.
Note: Since I wrote this in 2001, digital cameras have made considerable progress. My current take is that a 6MP digital camera can match most the quality of equivalent 35mm film cameras under most condtions. Exceptions might be: using Velvia or Technical Pan while shooting tripod mounted.

Can you use Minolta manual focus lenses on an autofocus body? I have heard that there are adaptors.

I'm sure I've mentioned this before. An adaptor exists. It has a piece of glass in it, kind of like a teleconverter. Why? If you've ever used extension tubes (which are great, by the way!) you would notice that when the lens gets further away form the camera, the focal plane gets closer to the front of the lens, but the lens will no longer focus to infinity (the depth of field gets narrower too). Now this is just what you want for macro photography, but not for much else. Back to the adapter. The MC/MD and AF mount rings are different sizes (the MC/MD ring is about 30% smaller). So one side of the adapter accepts the MC/MD lens, the other mounts to the AF body. Now an adapter that can do this, purely from the mechanics, is of necessity several millimeters too thick. Without correcting optics, it would become a short extension tube. So to allow the MC/MD lenses to focus to infinity, a pieces of glass is necessary to correct the focus. Now this piece of glass, that is about 2cm in diameter (not ideal for large aperture lenses in the first place) is not of very high quality (reasonable quality, to be sure, but not high) in any of the models that I have seen. So when you mount your expensive lenses on this $40 adaptor, they all become considerably worse (I've done tests with an MC 58mm f/1.4, an MD 28mm f/2.8 and an Celtic 135 f/2.8). The resulting pictures look pretty bad, when compared to these same lenses on the proper camera body. Put in absolute terms, the results were worse than the cheapest 28-200 AF zoom in every area except distortion. That is, sharpness and contrast suffered noticeably. If you never enlarge your pictures beyond 3x5" (9x13 cm) then you may not notice. Likewise, if you have never developed an eye for variations in contrast between lenses, and can't see the practical difference between a $100 zoom and an $800 fixed focus lens, then again, you won't have any problem with the results. In my test, a Sigma UC III 28-105 AF zoom gave instantly visually better results than the best lenses through the adaptor, and on 3x5" prints! No magnifying glasses, no getting really close. Lay them all out on the table, and you can pick out the ones from the adaptor vs. the ones from the Sigma zoom from a distance. Now I don't want to exaggerate the differences, but there was a huge quality difference! The pictures through the adapter are still better than most plastic lens point& shoots, but that is not a very good reference point. Of course, the MC/MD lenses are wonderful on my SRT cameras (and better than the Sigma zoom). Well, I hope that answers your question. Yes, you can do it, but do you want to pay the price? Technical note: The trick to get the adaptor to work on an HTsi is to hold down the spot meter AND self timer buttons WHILE turning on the camera - this will override the shutter-release failsafe, allowing you to take pictures in aperture priority mode.).

I have heard that there are some Sigma autofocus lenses that don't work on some Maxxum cameras. What is the story?

The last time I heard of one of those, it was a case of an early Sigma lens that only worked with the first series of Minolta AF cameras (7000 and 9000) but was software incompatible with the later versions. In addition to manual focus, you could only shoot with aperture wide open, because the Minolta AF lenses have no aperture ring, as this function too is software controlled (through a ROM chip in the lens). For details, see this page.

I would like a wide angle lens to use on my Minolta manual camera body. Is the [insert any third party lens] any good?

While there may be some notable exceptions that I am unaware of, most older third-party MF wide-angles are pretty bad (I had a Makinon 24mm f/2.8 (before I knew any better) that was so bad the edges were vignetted and the whole image was soft, noticable even on a 3x5" print; I got rid of it quickly). Newer (last five years) thrid-party wide-angles are the same design as their AF counterparts, so for example, the Sigma 24mm (see my other post on the topic) does better even than the Minolta counterpart. Buying used, it can be hard to tell the year of a design, and it can be pretty risky getting a third-party wideangle. Remember, wide angles are pretty hard to do well, especially compared to 50mm or even 135mm. I have seen quite a few very good 135mm third party lenses for minolta. I have a minolta 28mm f/2.8 celtic that I got cheap once. I was got it to give it away to someone,but I was so happy with the results that I kept it, and have been using it regularly ever since. I've seen them for as low as $40, both on e-bay and at places like cameta.com. That is what I would suggest. KEH.com is another of my favorite places to get lenses.

I read that you use the sigma 28-105 zoom lens. I have it and it sucks.

In dealing with the Sigma 28-105 lenses, remember that there is the 28-105 4-5.6 UC, the 28-105 4-5.6 UC II, and the just-released 28-105 3.8-5.6 UC III, as well as the 28-105 2.8-4. According to the test results, each new version of the 4-5.6 UC make was better than the last. I have the latest (UC III) and find it quite good for the "if you just have one lens" situations (just shot four rolls with it today). It has a minimum focusing distance of about 19", and does adequatly on an HTsi plus as far as focusing speed. If you have the old UC, you may be quite pleased with the UC III, and it is a lot less expensive than the 2.8-4 version. I would not recommend it over top quality prime lenses, however. It is, after all, an all-purpose zoom.

Is the 24mm f/2.8 sigma lens really better than the Minolta version?

I had written earlier that Sigma's 24mm f/2.8 autofocus lens was sharper than Minolta's, relying on, among others, photodo.com's tests. Someone (I forget who) corrected me, saying that while Sigma was sharper at the center, Minolta was sharper at the edges. I went back to photodo.com and checked the two. Looking carefully at every single measurement for both lenses, I must report that the graphs show the Sigma lens to be sharper than the Minolta at ALL areas of the lens at f/8. At f/2.8 the lenses are closer, but Sigma's is still sharper at every point on the negative. Remember, this test is of resolution only, and says nothing about color, contrast or bokeh. Still, I would like to give credit where credit is due. Photozone.de 's lens survey (not the reader survey, but the average of the magazine reviews) also rates the Sigma ahead of the Minolta version. Lens tests abound, especially on the internet. They can be subjective, a sort of write up/near advertisement, or objective, such as sharpness, and distortion (a la photodo.com).

I should note that samples vary considerably among Sigmas. The good ones are very good, but there are quite a few lesser examples floating around as well. Test any lens you are considering before purchase (or after purchase, and then sell it quick on eBay if it doesn't measure up).

What is the best lens for [insert subject]?

There is no such thing as best in lenses. At best there is "best sharpness" or "best controlled background blur." These are, of course, highly desireable qualities, under most circumstances, and may even cause someone to rate a lens "best all around." This means that under the greatest number of circumstances, this will be the best lens. This does not, however, mean that it is the best lens under all circumstances. If you want to bring out the subtle tonal gradiations, in a face or a locomotive, Minolta G lenses will generlly do an excellent job. If you want a punchy shot of a snow-boarder in mid-air, well, G lenses will do a great job, subtle tonal variations and all... but that may not be exactly what you are aiming for. And suddenly we are into the realm of preferences. Preferences are not objective, and as such are hard to argue. Actually, they are very easy to argue, and many people do, vigorously, and to no end, but ultimately, they are just preferences. Anyway, I cringe when I hear "best lens." Best lens for what? The artist in me loves to explore the possibilities.

I have the 50mm f/1.4 and the 100mm f/2.0. What else can I get that will give me more coverage in the wide ranges?

The two you mention are the sharpest pieces of glass Minolta sells! Remember as you get into the lower focal lengths that it becomes more difficult for a manufacturer to make a lens of the same sharpness as 50 or even 100mm. That aside, the 35mm f/2.0 and the 35mm 1.4 are both almost as sharp as the other two you have. Interestingly, Sigma's 24mm f/2.8 is also very sharp (photodo 4.0) and as such well ahead of Minolta's 24 f/2.8 (3.4). The 28 f/2.0 rates better than any other option at 28mm. So, if you like to spend money, and want only the best, consider the 28mm f/2.0 or the 35mm f/1.4.

How good is Minolta's 85mm f/1.4?

It is usually rated as one of the top in it's class. But a better question is, how much production variation exists between lenses of the same make and model? If you took 100 different 85mm f/1.4 lenses and ran the same tests for, say, resolution (lines per mm) under controlled conditions, how much would the results vary from lens to lens? 2%? 10%? I find this question important, since so many of us rely on these "objective" tests in buying decisions. From what I have heard, there is little variation among the top lenses: it is the cheap ones that vary a lot. Which probably explains why people have such heated discussions about Sigma and the like (It's great, it sucks! back and forth about the same lens).

Why can't I get a lens that shows me the world as it really is? My eye is a lens and it has no problems!

You have forgotton the very basic limitation of the lens vs. the eye. If you look a a scene that includes both background and foreground, your eye focuses first on one, then on the other. (More specifically, you usually use both eyes look at the scene). This is what you see. Now, when you attempt to capture the same scene and preserve it on film, it becomes necessary to sacrifice certain design advantages of they eye and use a lens to get it there. The first thing to go is the third dimension. It's loss and how to manage it is essentially the art of composition. The next sacrifice is continual focus. The lense must focus on one plane, some aspects of the picture will usually be out of focus (there are exceptions, such as when you focus on a two dimension subject - and note that most lens test charts are two dimensional - and when your view is blocked). Since most of us are limited to a few lenses (few if any carry hundreds) we must work around the limitations of what we have. This involves putting up with out of focus areas that could concievably be avoided with a different lens. Having described in principle WHY we must put up with less than a perfect reproduction of reality through a lens, the questin turns to the trade-offs possible in making a picture. Each weakness can be turned to advantage is the photographer (artist) is conscious of what he is doing. Areas that are widely discussed and easily measured include sharpness, distortion and flare. More difficult to measure, yet still empirical, include contrast and color balance. One area that has recieved very little attention is how a lens renders the areas that are out of foucs. The area most of up probably do not pay any attention to is the out-of-focus portions of the picture (bokeh). In sum, you CAN'T get "what you see" onto the film, and asking for THE piece of equipment that comes closest is surrendering an important area of artistic control to someone elses judgement. There is no "closest," only trade-offs. Understanding this, the question becomes, "Given that I can have either this or that, which one best represents the scene as I wish to convey it?" And this is what makes being a photographer so much fun!

What is Bokeh?

Bokeh refers to how the lens, based on its design, renders the out of focus areas. Logically, no lens test chart will measure this, since they are made by focusing on a two dimensional chart. These two dimensional charts are great for sharpness and distortion, but tell us nothing of how the out-of-focus areas will look. The aspect of the lens design that influences this the most is the aperture shape. I would like to write more about what exactly causes what, but I would need to do more research first.

How does the proformance (image quality and AF speed) of the classic maxxum 70-210 f/4 compare with an off brand (ie. Tamron) 70-300 f/4-5.6?

Well, as far image quality goes, the Cosina (Tamron) does pretty poorly aginst the Minolta (MTF 0.9 vs 3.8 - the scale is 1-5). Speed, well... Since the Minolta is older and heavier, it is slower to focus. Some bodies you will hardly notice the difference, other bodies, there will be a more noticeable difference.

It looks like Imight have to start photographing some old buildings, and since I'll be traveling/walking a lot, I'd like to carry a single lens. I don't want the buildings to look any more crooked than they actually are! Any suggestions?

I don't know if this is possible, but... Try to get a ways back from the building, then photograph it with the 35mm f/2.0 (the 1.4 would work as well, but it is 3 times the price and the same sharpness). The 35mm f/2.0 is a VERY good lens. If you can get access to the building across from it, you could take the picture from one of the upper stories, and that would be best of all. Otherwise, depending on your needs (i.e. how close to the building you are forced to stand) any of the other Minolta primes would do well as well (28mm f/2.8, 24mm f/2.8, 24mm f/2.8 20mm f/2.8). Obviously, the closer you are to the building, and the wider the lens, the more pronounced the "keystone" effect will be. This is why I recommended the narrowest lens lens practical, combined with the greatest distance possible. With a really wide lens you can take the picture with the film plane perpendicular to the horizontal, then cut off the bottom half of the picture. This will minimize distortion, but the keystone effect remains. With a darkroom, you can equalize it a bit by tilting print paper so the light falls on it at an angle, essentially reversing the keystone, but this takes some experimentation to get right.

I have some extra money in my pocket. I don't know if I should upgrade to the Maxxum 9 or buy a Maxxum 200mm f/2.8 lens. Advice?

Glass is the most important part of taking pictures (well, aside from the photographer). Everything else just supports it. The 9 won't get you better pictures (in all but a few, extreme circumstances). The 200 2.8 will, especially 8x10 inch prints.

I have the Maxxum 70-210 f/4 and an HTsi. The lens is almost bigger than the body, and just as heavy it seems to me. AF is OK, but not spectacular. Should I upgrade?

Aw, come on. The lens is way heavier than the body! (I'm serious!) I should point out, however, that the relative weight of the lens and body are irrelivant to focus speed. Important are the power and speed of the motor driving the AF, and the weight of the element that needs to be moved in focusing. The HTsi's AF motor is perhaps weaker than the 9, but more or less on par with the 600si. As for the lens, it may have heavier front and rear elements, but the heavy parts are not what is moved. In essence, it won't be a terrible combination. I'd like to see a benchmark matrix of focusing speeds on all the different Minolta lenses on all the different bodies. I suspect the variations would not be as dramatic as some would expect. And a final note: Focus lock is a function of the camera's computer and the conditions of shooting. How fast a camera can move a lens from close to infinity, i.e. the raw speed of focusing, is one factor. How well the computer chip can find a focus lock, and whether that is the plane you want in focus, could also be called "focus speed" but is a software, not hardware. There is probably more difference in software between the various current Minolta models than there is in hardware. The higher end bodies can, from all accounts, focus under more difficult conditions (low light, lots of things in fore- and background) than the less expensive models. Low light is also a factor of aperture, so "extreme conditions" could be a f/5.6 lens with a 2x teleconverter on an overcast day.

I got my pictures back from a used Minolta HiMatic. It is hard to believe that a $17.00, 38-year old camera can produce such exceptional image quality. It is also very hard to believe how consistently "dead on" the exposure was... especially when you consider that this thing has no "computer" inside and doesn't even use a battery!

Well, we could be seeing any number of factors here. The aspect of prime lens design vs. zoom has been touched on. I would also submit that in sharpness, you are seeing the results of no mirror shake and less hand held movement in the HiMatic as compared to your SLR's. All of us SLR guys discount these things, probably because they are too difficult to correct, and doing so would take all the fun out of snapping pictures. Still, the influence of mirror shake is well documented, empirical and incontrovertible. MLU is helpful for shots starting at 1/60 and essential at 1/15, even hand held! And speaking of hand holding, a heavy SLR with a heavy lens attached is likely to undergo more movement when taking a picture than a lightweight rangefinder. What rotation there is will have less effect on the rangefinder because center of gravity (and usual pivot point) is closer to the film plane. All these things we never tend not to show themselves on cheap prints. Try making a slide and projecting it to 6 feet tall. Walk up to the wall and check the edges of the objects in your photo for sharpness, and then you will see the results of hand movement and mirror shake. Properly tripod mounted with mirror lock-up (pre-fire, actually) your 9 with the Sigma can probably do everything the Hi-Matic can. Put a Minolta 50mm f/1.4 on there and it will blow the Hi-Matic away. Still, how many of us carry a tripod around with us for every shot? The Hi-Matic has some design advantages native to all rangefinders (light weight and lack of mirror) that make the "easy" snapshots (from a light-metering perspective) come out better almost every time. SLR people, it seems, continually re-discover this.

What is the SRT battery problem?

Old "Circle and Needle" metering manual cameras (Minolta SRT's among them) were built to run on a 1.35 mercury battery. Mercury is very poisonous, and mercury batteries are now illegal. The replacement alkaline batteries in those same sizes are all 1.5 volts. The extra voltage makes the light meter oversensitive, and all the pictures come out underexposed. I had an SRT that was working fine until I changed the battery, and suddenly the light meter got VERY sensitive. There are four soultuions.
1. Get an illegal 1.35 volt mercury battery from a country were they are still made (Mexico, eastern europe).
2. Get a 1.35 volt zinc-air battery.
3. Have the whole camera converted to 1.5 volts.
4. Get a small device to convert the voltage of a 1.5 volt battery to 1.35 volts.
Advantages and Disadvantages of each solution.
1. 1.35 volt mercury batteries. Advangtage Original battery Disadvantage Hard to find, environmentally insensitive.
2. 1.35 volt zinc-air batteries. Advantage Proper voltage Disadvantage. Good only for a few months; run down even when not being used. Cost about $6 each.
3. Having camera converted. Advantage Will then use commonly available $2 batteries. Disadvantage Costs almost as much as another "used" camera ($130-$160). Two approaches possible. They add a capacitator to reduce the voltage (which you can do yourself for a lot cheaper - see below). Or they recalibrate the dials (usually the ISO dial) to compensate for the increased sensitivity. I have read, but not verified, that the metering is not as accurate after this rather expensive proceedure.
4. Buy a small converter that will change the batteries voltage from 1.5 to 1.35 volts. I have seen two for sale, http://www.olympusguy.com/NewLArt8.htm (they work on Minolta's - the Olympus OM-1 has the same problem) for $5 and the MR-9 at http://www.criscam.com/cris2i.htm for $30. The difference between the $5 version and the $30 version is that one is teflon, the other is metal. They should both work equally well, and you only have to buy it once. Further, I have read (but not verified) the Silver Oxide hearing aid batteries work better than alkaline batteries in the converters, supposedly because silver oxide gives off the current at a more even rate than alkaline. I have done quite a few tests with just about all the options, converters ets. and found that the hearing aid battery solution is the most practical and cost effective. The battery size is not important, only the thickness. Currently I am using hearing aid batteries that are only about half the proper diameter with no problems. They cost $3 to $4 for a 5-pack. I am still doing testing to see how long they last. By all acounts they don't last as long as the "old" mercury batteries, but I am still on my first one two months later. Note on proceedures: I used a multimeter to test the actual voltage of just about every type of battery I could get my hands on. Most were as marked to within 10% Then I used a lightmeter, and SRT and an HTsi plus on spotmeter to check the readings off an evely illuminated wall. Standard deviation seemed to be about 1/3 stop. I found that 1.4 volt batteries gave me a "good enough" exposure reading for negative film, that is, within +/- 1/2 stop of where it should be. I couldn't get any more precice with the available equipment.

Daniel Hindes - March 2001