Digital SLR Crop Factor – Boon or Bane?

There’s a lot of confusion when it comes to using lenses designed for 35mm cameras on the current crop of Digital SLRS. Many photographers have sizeable investments in 35mm lenses for their film cameras, and for the most part their lens investments drive them towards a particular digital camera body, whether it’s Nikon, Canon, Minolta (Sony), Pentax or Olympus.

Luckily, all the manufacturers retained their old AF mounts, except for Olympus, which uses the newly designed Four-Thirds mount. Sony retained the Minolta ‘A’ autofocus bayonet mount for the Alpha series cameras, allowing all the fine 35mm lenses out there since 1986 to be used. The same goes for Nikon and others.

However, due to cost constraints at the present time, most digital SLRs use a sensor that is smaller than the 35mm format size of 36mm x 24mm. This smaller format is 22.7mm x 15.1mm, and is known as the APS-C format. Sony and Nikon (and others) use a sensor size that is approximately the APS-C format size. As can be seen, the APS-C size provides a much smaller image area, 342.77 square millimeters versus 864 square millimeters for the standard 35mm format.

When a 35mm lens is used on the current crop of digital cameras, the smaller sensor size means that the 35mm lens will now have a narrower angle of view (also called FOV or field of view) than when used on a 35mm film camera body. This is due to the fact that the 35mm lens creates an image on the film (or sensor plane) that is is sufficiently large enough to cover the 36x24mm frame it is designed for.

When used in a Digital SLR that has a smaller sensor (and thus image size), the image formed by the 35mm lens is still the exact same size as before, but the smaller sensor can only use a portion of it. In effect, this constitutes an “in-camera” crop. This cropping is determined by the ratio of the sensor size to the 35mm format size, distance of the image plane from the front of the lens etc.

In most of the cameras using APS-C size sensors, the ‘cropping’ is equivalent to using a lens that has a narrower angle of view (telephoto effect). This Crop Factor (also known as Focal Length Multiplier) is around 1.5x (Sony Alpha) 1.6x (Nikon). In some cameras, Canon uses a sensor size that is slightly larger, which gives a 1.3x factor (this is the APS-H format). The Four-Thirds system used by Olympus and Lumix (Panasonic) has a 2x factor.

The focal length does not really change, of course. The smaller sensor’s ability to register only a portion of the total image causes an APPARENT increase in focal length due to the cropping. This has the effect of using a lens with a narrower angle of view, the same as using a telephoto lens. (Luckily, the sweet center portion has the sharpest part of the image).

The image edges which may not be sharp, or have aberrations are cropped in-camera. For the user, it’s easier to remember by multiplying the focal length of the lens they are using with the factor for that particular body, and that gives us the APPARENT focal length.

A lot of the confusion can be eliminated by using the term APPARENT rather than EQUIVALENT. for example, on my Sony Alpha 700 (which has a 1.5x multiplier for 35mm lenses), it would be more accurate to say that my Minolta 50mm lens has an APPARENT focal length of 75mm, rather than saying my Minolta 50mm is EQUIVALENT to 75mm.

This apparent increase in focal length does not affect the aperture, so the APPARENT focal length of 75mm is still at a fast f/1.7. This will serve as an excellent portrait lens, since it can frame head and shoulders perfectly, but you’ll find yourself having to move back when you want to include more of the scene.

For most wildlife photographers, birdwatchers and even landscape photographers, the apparent increase in focal length can be a unexpected blessing – they get more ‘bang’ for the buck from their existing lenses. When coupled with the higher ISO capabilities of DSLR cameras and in-camera image stabilization that will let them handhold the camera in situations that would have required them to lug along a heavy tripod.

If you’re using a MACRO lens, such as, for example my Sigma 50mm f/2.8 (a very sharp lens with a true 1:1 macro capability) the apparent increase in focal length permits the macro subject to be fill the frame without moving in as close. Since the stand-off distance is greater, more light can reach the subject. The increased distance also helps when photographing skittish subjects that are likely to fly or hop away if approached too closely.

When the subject is framed in the Sony Digital SLR, it is seen that the Depth of Field is greater for the same magnification when compared to using the lens on a 35mm film camera like my Minolta Dynax 800si. This is a great advantage for macro-photography where depth of field and subject lighting are always problematic.

The whole situation is different when it comes to wide angle lenses. This is where most photographers are ready to burst into tears. The 1.5x or 1.6x multiplier effect holds good on the wide angles too, and this means that a normal wide angle like 24mm lens which would give a 74 degree field of view on a 35mm format camera will now only provide a FOV of 62 degrees or so, approximately that of a 35mm lens. In the same way, an ultra-wide 16mm becomes an apparent 24mm a 28mm is an apparent 42mm and a 35mm lens behaves like a 52.5mm normal lens.

Given the fact that most wide angle lenses are EXPENSIVE, no photographer would like to see his investment reduced to a moderate wide-angle or a normal lens. However, such is life. You win some, you lose some. To get a true wide angle on the Sony Alpha 700, I would have to invest in a 18mm to get 27mm (luckily, that’s included in the zoom range of my Sony 18-200mm lens that I bought with the camera). Since the 18-70mm is bundled as a kit lens, most owners will have at least a 27mm wide angle, albeit a slow one).

To get the 24mm, we’d have to invest in the very expensive Sony 16-105mm Zeiss coated zoom lens (apparent focal length 24- 157.5mm). Buying a faster wide-angle prime lens would be prohibitively expensive for any amateur, and even professionals would hesitate.

My advice? If you really need to shoot wide angle, just use your film camera. You can still buy a fine Sigma 24mm f/2.8 AF at a reasonable price. The Sigma 24mm is a good deal, since it had a matte black Zen finish that tended to flake off, giving the lens a “very used” appearance and usually marked down. This is just cosmetic, and does not affect the lens performance in any way.

The same Sigma lens was re-badged and sold by Ritz as their house-brand Quantaray lens, but with a different, more durable finish – but it’s still the same lens. Don’t be fooled by the appearance of either lens – this is a very high quality lens. Besides, you can always use the Sigma on the digital SLR as an apparent 35mm f/2.8 prime lens in place of a ‘Normal’ lens. You’d pay hundreds more to get a similar “designed for digital” Nikon, Sony or Canon lens.

Of course, all this talk about crop factors and multiplication factors will become moot when Full Frame digital SLRs become common. Canon already has one, and Nikon and Sony will follow shortly. In fact, I would not be surprised if the Sony Alpha 900 was not released in a few more months. When that happens, lenses will behave as they were designed and there will be no more confusion.

As for me, I rather like the fact that my Tamron 70-300mm now behaves like a 105mm-450mm super-zoom. With the Image stabilization turned on, I can actually hold that baby steady enough to use hand-held.

---

This work by Ajoy Muralidhar is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.
text and images © 2008 ajoy muralidhar. all names, websites, brands and technical data referenced are the copyright or trademark of their respective owners. thank you for visiting olympuszuiko.

 

Film Blues, and a note on Olympus OM manual lens compatibility with E-Series DSLRS

A few weeks ago, I came across a question by another WordPress blogger asking – why does anyone use film anymore? That got me thinking… I left a comment on the post, of course, but I felt that the “Why” aspect needed to be better clarified, and hence, this post.

I don’t shoot much slide film – too much of a hassle to develop and an even bigger hassle to convert to digital format. I’ve used ScanCafe in the past, and they provided me with EXCELLENT service. Still, it means waiting a week for your slides to come back from the film processor, and then shipping them to ScanCafe for scanning at 3000dpi, approving the scans online, and then waiting for the finished DVD – a process can take 3 to 4 weeks, depending on how backed up they are. I would probably shoot more slide film if it was a cheaper and faster proposition.

Now, I mainly shoot 200 ASA color negative film, and on special occasions, a roll or two of Ilford Black & White. There are so many costs associated, and being on a budget, I use my local Walmart in Westminster for processing. Since I have been dropping off film for a while now, all the photo technicians know me quite well, and take extra care when developing my rolls. I don’t make prints, just ask for the processing, and transfer to CD. They develop and put it on CD for me in just over an hour, no prints for $4.25. A 5 pack of Fuji 200 ASA costs about $5.99. So it costs about $5.45 to buy and process each roll of film.

Darn. Digital would be so much cheaper, and an Olympus E-500 package (8 MP, currently $650 with 2 lenses) would practically pay for it itself in the film cost equivalent of about 150 rolls. That said, there is always the higher resolution of film, when scanned. I get 13.2 Megabytes on average on my scans, but since I don’t make any prints, it’s a moot point. I always have to bring them down to about 200kB for posting online anyway. Besides, an Olympus xD 1 Gigabyte flash memory card only costs about $30, and can hold 200 pictures at 5 Mb each. That’s more than 8 rolls of standard 24 frame film.

For me, it’s about my manual cameras, and the manual lenses – not really about the media… What’s important to me is the way the feel in the hand, their heft and feedback, both tactile and audio. Now if there was someone manufacturing “digital” backs at a reasonable price that could be retrofitted onto all the beautifully engineered older cameras out there, I suspect that you’d probably see most of the film crowd abandoning the medium in droves.

The amateur photographer is a canny animal – not being collectors, we are usually on a shoestring budget, and while the pleasures of film are considerable, the disadvantages have to be considered as well. Film does holds one back from experimenting and improving as a photographer, since we never get to explore various perspectives and multiple shots since the cost of film processing is always at the back of our minds. Digital media offers the opportunity to shoot the same scene at different exposures without worrying about using up film. Since practice makes perfect, digital cameras do help us improve and grow as photographers, since there is no cost barrier once the initial (considerable) investment on the DSLR is made.

As for me, although I love my solidly built manual cameras, they are only light-tight boxes. I am an user, and I like to take pictures. If film finally becomes a cost-prohibitive barrier to shooting, then I will have to bow to the inevitable. I would hesitate to call it progress, though. Ha ha. I know that I can use my beautiful Zuiko, Kiron, Komine and Panagor lenses on a Olympus DSLR, but the Olympus made OM to Four Thirds MF-1 adapter has lots of limitations, and that worries me. I have 10 Zuiko lenses and a bunch of Kiron, Vivitar and Komines. I would really like to use them on a Digital SLR, but the adapters available may just not permit it.

The Olympus MF-1 OM Four Thirds Adapter manual lists the compatible lenses, and that is pretty extensive – what is troublesome is that most of the OM series lenses will only work in a limited f stop range – typically f/4 – f/8, and thats not much use to me, since I hardly every shoot in that range, except in overcast conditions and for portraits. I generally set my lenses in the f/11 – f/22 range as I use the Sunny 16 rule, most often at f/16 (f/11 if I am using a polarizer).

I am holding out because I feel that we haven’t seen the best that Digital SLRS can offer yet. Olympus is selling the 10 megapixel E-400 only in Europe, for some reason – in the US, we have the 8 megapixel E-500, and the older E-300, E-330 and E-1 models available. Olympus announced the 10 Megapixel E-510 bundle late last month, but they are not in stores yet, although most sellers are accepting orders. The E-510 with the 2 lenses should come in at less than $1000, which is a great price (although not as attractive as $650 for the E-500).They also announced the E-410 for the US market, and I expect that it will have a pricepoint a little below the E-510.

As an alternative, I could also choose a Sony Alpha 100 (Minolta) body and get to use my Maxxum AF lenses (1.5x on the Alpha – ie, my 50mm will be a 75mm as opposed to the 2x on the Olympus eSeries). The Sony Alpha 100 is a great camera as well, and costs about $1050 for the 2 lens kit. I don’t particularly like Sony’s proprietary memory sticks, but thankfully, the Alpha takes a CompactFlash or a CF MicroDrive, same as the E-500. Hey, the xD card is a proprietary card as well. I wish they’d all stick to one format – say Secure Digital cards which have a much higher memory storage capacity. (or build in a 4 or 8 Gigabyte CompactFlash microdrive into every camera as internal memory and be done with it).

The one very great advantage of the Sony Alpha 100 is that it will take ALL my Minolta AF Maxxum and 3rd party AF lenses made in the last 20 odd years without an adapter – I’ve a Sigma 50mm f/2.8 Macro, a Maxxum AF 50mm f/1.7 standard lens (simply superb), a Maxxum AF 28-80mm xi, a Maxxum AF 80-200mm, a Maxxum AF 35-105mm, a surprisingly excellent Phoenix 28-105mm (I consider this a hidden gem), and a Tamron 70-300mm and a couple of T-mount preset lenses – all in all, a considerable investment that would happily not go to waste… in addition, I have a fine little Bower made Olympus lens to Minolta AF body adapter that allows me to fit my precious Zuiko and other 3rd party Olympus lenses to the Sony Alpha. Thank you Sony, for respecting all the Minolta AF camera users and retaining the solid Minolta AF mount.

---

text and images © 2007 ajoy muralidhar. all names, websites, brands and technical data referenced are the copyright or trademark of their respective owners.

 

Cheap Super Telephoto Lenses Part I – T-mount Spiratone, Vivitar etc

A while ago, I had discussed the advantages of mirror lenses as cheap long focus lenses, and more importantly, the fact that they could be used in hand held photography. In the same post, I had explored alternative lens configurations that were available at reasonable cost, which would enable an amateur photographer like myself the opportunity to experiment with super-telephoto lenses.

The choices I had that were available in Olympus mounts were considerably varied, and although all the lens and teleconverter combinations would provide a reasonably fast, cheap lens in the super telephoto range, none of them were suitable for hand-held photography. There are some other alternatives I had not really explored since they involved even older lenses, from the 60’s and early 70’s, specifically, universal thread T mount lenses.

These were the old days, before the development of modern multi-coated optical glass and computer aided design. The long focus lenses from back then are really something – they are solidly built, heavy, and have come fitted with a tripod ring so as not to damage the camera mountings. These lenses were made by Cambron, Tele-Astranar, Lentar, Spiratone, and of course more familiar companies such as Tamron, Vivitar etc. Some of them were sold with a particular manufacturer’s mounts, but since camera mounts changed a lot back then, many lenses were made with something called a “T mount”.

Tamron introduced the T mount back in the late 1950’s as a potential “Universal” lens mount. The reasoning was very simple… The T mount is a threaded screw mount, similar to the Pentax M42 screw mount, but with finer pitched threads. The Pentax screw mount is a 42mm diameter screw with a 1mm pitch (M42x1), while the T mount has a 42mm diameter 0.75mm pitch (M42x0.75). The lenses were threaded at the back to take an adapter for a specific camera mount – Nikon, Canon, Olympus, whatever – once a customer bought a lens, it would be fitted with the adapter of their choice and that was it. There was no need to stock many lenses with different mounts – the dealer only needed to stock up on different mounts. If a camera manufacturer introduced a new model with a different mount, a new adapter became available. In fact, some lenses were only released with a T mount – a good example is the famous Vivitar Series 1 600mm Solid Cat (Solid Catadiotropic Mirror lens – what a mouthful)

Theoretically, if you had the right adapter, a lens could be fitted to any camera. The T mount also became the standard for bellows, enlargers, telescope adapters, microscope adapters etc. This happy state of affairs existed for many years, until variations of the T mount started appearing that were incompatible with one or the other lens ie, T2, T4, TX and pretty soon, everyone went back to making their own proprietary mounts. But the story does not end here… Due to the huge number of lenses that were made for the T mount, and the easy availability of adapters for different makes of cameras, T mounts never went out of favor – they are still widely available cheaply on Ebay and elsewhere.

What of the lenses? The big issue with older 3rd party lenses was that they were usually built cheaply, and that the lens elements would shake loose in their mountings after a while. Like everything else, not all 3rd party lenses were built the same, there are lots of solidly built ones as well, We just have to be choosy. There’s plenty of choices, and we don’t have to settle for one with a hazy element or fungus or even bad cosmetics. Back in the days when the T mount was common, everyone shot color slide film. Slide film is very finicky and not as forgiving as color print film (common negative film) and does not have as wide a range, so the lenses had to be good (at least fairly so), or they would never sell.

Even the cheapest lenses had a large sweet spot in the center of the lens, and when stopped down, they could provide excellent results. Now, I am not advocating that we compare it against a razor sharp professional Nikon OEM lens which probably costs 10 times as much. Rather, we should judge the lens on its own merits, and the low cost. Also, sometimes, razor sharp may not be necessary, especially if we are just planning on a small print, or just to post online – besides, when did film resolution ever match the resolutions possible with a lens? If we are not satisfied with the edge resolution, we can always crop it out. It should not be an issue at f/11 or smaller anyway.

T mount lenses are available in every focal length, but since this post is about super-telephoto lenses, I will discuss 2 famous representatives of cheap super-telephoto lenses from the T mount days – the widely available Spiratone 400mm f/6.3 and the Vivitar 300mm f/5.6. Both still easily available all over the place.

Spiratone was a camera dealership very much like Ponder & Best (Vivitar) and the brainchild of S.F (Fred) Spira. He ran a store in NYC, and they were famous for a wide range of affordable equipment. Fred Spira is also the author of the well regarded “The History of Photography: As seen through the Spira Collection.”

The Spiratone 400mm f/6.3 lens was most probably made for them by Tamron. There were several labels of this particular 400mm f6.3 lens, all identical, which implies they came from the same production line. They were branded as Spiratone, Tamron, Tele-Astranar, Cambron, Howard Sterling and probably a few others. I guess Tamron was trying to break into the US market back then, and didn’t mind having their brand diluted by all the other 3rd party names. This lens has an aperture range from f/6.3 to f/32, and is pretty sharp stopped down to f/11 or smaller. Of course, for smaller apertures, the exposure would make a sturdy tripod a necessity. On a bright sunny day, a hand held shot at 1/500 and f11 using 400 ASA or faster film is a distinct possibility.

There’s more pictures of the Spiratone 400mm f/6.3 along and the 60mm close-focusing extension tube here. Scroll down to the bottom of the page.

Here are some examples with the 400mm Spiratone

Spiratone 400mm f/6.3

Spiratone 400mm f/6.3 – Preset Aperture setting rings

Spiratone 400mm f/6.3 – T mount threaded end

Spiratone 400mm f/6.3

---

The Vivitar 300mm f/5.6 is an early Vivitar 35mm lens. As we all know, Vivitar (Ponder & Best) used to contract out their lens manufacturing as well. Everyone is familiar with the famous Series 1 makers – Komine and Kino Precision, but Vivitar contracted out with Tokina (aka Asanuma) and others — including OLYMPUS – yes, Olympus Optical Co. The Vivitar 300mm f/5.6 was one of the lenses made by Olympus (at least, the ones with serial numbers 6xxxxxx.

We certainly can’t fault the lens in construction – The Vivitar 300mm f5.6 is built like a M1A1 battletank. The Spiratone is solid too, but not as heavily built as the Vivitar 300mm. Mark Robert’s website has a list of the other manufacturers and the serial number codes. Check under the heading Photography. He has a bunch of lens mods and Pentax information as well.

Ever since I came across this bit of manufacturing information, I had been on the lookout for a Olympus made Vivitar lens. Common sense dictated that any such lens would have to be pre-1972, before Olympus entered the interchangeable lens SLR market in earnest with their OM series cameras. Any T mount lens that they would have made as a Vivitar contractor would have to be between 1965-1972, BEFORE they introduced the OM bayonet mount. Additionally, it made sense, as it would have been good practice for Olympus in getting their Zuiko OEM manufacturing processes worked out. The lens shouts “quality” as soon as you pick it up. It’s very heavy for it’s size, and takes a 62mm filter. The pre-set aperture rings are surprisingly easy to use.

Vivitar 300mm f/5.6

Vivitar 300mm f/5.6

Vivitar 300mm f/5.6 – preset focusing rings

Vivitar 300mm f/5.6 – T mount ring for OM

Here are some compelling reasons to jump in acquire a cheap USED long focus lens or two to play with and experiment with super-telephoto effects:

# I own a beautiful Olympus Zuiko 300mm f/4.5, I would not risk it in the field ie., while hiking in rough areas etc. There’s a lot to be said for having a cheaper 300mm or 400mm that we can throw in the backpack without hesitation. A far as sharpness goes, these lenses a a little sharper than the common 500mm f/8 mirror lens, but the mirror can easily be hand-held, while these long lenses need Tripods.

# Both the lenses are sold for between $25 and $50 on eBay regularly, sometimes going cheaper if they have some cosmetic issues. These lenses were single coated for the most part. Multi-coating of lenses was still a few years away, and they usually came with a generously sized screw-on or built-in sliding lens hood. At that price, they are a real bargain, since a T mount adapter can be had for another $10- $15, and sometimes the seller will include one for your specific mount if available. Either way, its no biggie, they are freely available.

# We have excellent fast film available to us these days – 400 ASA and 800 ASA film allow us generous exposure latitude, permitting the use of filters and even a few mistakes. Hand-held is possible, but only if the light conditions permit speeds of 1/500 sec and above (WITH a polarizing filter, the light would have to be very bright, so it would have to be a very sunny day). I would recommend a tripod with these lenses any day. They are just too darn big. They come with their own tripod mounts, so why fight it? besides, it saves stress on the camera mounting ring as well.

# So what if the images are soft towards the edges of the lens? The sweet spot in the center will produce a sharp image when stopped down, to f/11 of f/16, and we can always use Picasa or Photoshop to crop the photo if needed. Due to the lack of multi- coating, the bokeh on these lenses is not as pleasing as their more recent (and more expensive) cousins.

# They can be mounted to a digital SLR with the proper adapter. On a Olympus E series DSLR, and a T-mount to Four Thirds adapter, the humble Spiratone 400mm f/6.3 becomes an enormous 800mm f/6.3 and the 300mm Vivitar f/5.6 becomes a respectable 600mm f/5.6. Can you imagine buying a 800mm DSLR lens for less than $50?

#Lastly, here are some excellent examples of what a Spiratone 400mm f/6.3 lens can do on an Olympus E-500 DSLR. I don’t think that anyone can complain about Christine’s beautiful animal photographs!

Spiratone 400mm setup

Vivitar 300mm setup

Here are the related Posts:
Cheap Super Telephoto Lenses Part II
Cheap Super Telephoto Lenses Part III
Learning to love your Mirror Lens

---

text and images © 2007 ajoy muralidhar. all names, websites, brands and technical data referenced are the copyright or trademark of their respective owners.

 

Learning to love your Mirror Lens

The Mirror or Reflex lens must be the most maligned, joked about and misunderstood of all 35mm lenses. Granted, it has some disadvantages, chief of them being the fact that mirror lenses are fixed aperture, and cannot be stopped down beyond their built-in f/8 settings. In some lenses, the f/8 is a manufacturer’s claim, and in reality, the setting may be closer to f/11. Even if it is f/8 as claimed, if we add any correction filter, we are stopped down to f/11 or f/16 anyway, which limits us to daylight photography.

Another disadvantage is that the viewfinder is not as bright with a mirror lens, and that focusing becomes difficult for cameras that are using a split prism focusing screen, due to the fact that the center spot goes dark. But by far the most pointed out disadvantage is the fact that the lens causes the out of focus highlights (bokeh) to be annular, doughnut shaped rings of light, and that is considered undesirable by many photographers.

Other disadvantages are that it either takes a large filter size (mine takes a 77mm screw-in) or that in some cases a small filter has to be inserted at the back of the lens, making it EVEN harder to focus. Due to these disadvantages, most enthusiasts who jump in and purchase a mirror try using it one or two times, and then put it away to gather dust, or trade it in the first chance they get. There are plenty that are available on eBay, used and new… at prices that are quite reasonable.

Look at the lens from another angle — as a potential long focus hand held lens. The mirror lens is usually available in focal lengths of 400, 500 or 600mm, with the vast majority available in the 500mm range. The lens is very compact, about 4 inches long, since the mirror design folds the incoming light a couple of times. Consider that these lenses have been around for many years now, and computer aided design has made them optically very accurate, and straightforward to design & manufacture. Better than that, it can be made cheaply, and most of the non-OEM brands can be purchased new for a little more than $100, with used mirrors going for even less. It usually weighs less than 1 lb, and can be easily hand-held, and does not look odd even on a small frame camera such as an OM-1 or OM-2. Some of them even claim to be Macro, although it’s just a close focusing capability which is very useful.

In my opinion, these lenses have an undeserved bad rap. Oh, don’t get me wrong, of course I would love to be able to afford a reasonably fast OEM refractive 500mm prime lens (say f/5.6), but other than the enormous cost ($1000++ range??) that puts it beyond the reach of all but the most dedicated amateur photographers, the lenses are large, and heavy. One cannot dream of hand-held photography with such a lens and a sturdy tripod would be a necessity. A professional photographer may have the resources and justification to purchase such a lens, since his or her professional activities and heavy usage call for it.

But what of the amateur who wishes to move into photographing birds, or just wants to have the opportunity to use a super-telephoto? There aren’t many low-cost alternatives. A few possibilities come to mind, but none of them seem suitable for casual handheld photography. Let’s explore what’s out there that’s relatively cheap, and gives us what we want– ie, a super-telephoto lens that’s reasonably fast, and comes in a standard bayonet mount. Handheld is ideal, but we will settle for something that will let us use a bean bag or some similar support, without having to resort to a Tripod and long exposures. There are other long focus cheap lenses in older screw mounts still available, and I will discuss them in another post.

# Using a mid-range zoom such as the Vivitar Series 1 70-210mm f/3.5 zoom (67mm filter size) with a 2x tele-converter. The tele-converter will cause the loss of 2 stops, but we will end up with a upper range of 420mm f/8 or thereabouts. If you are familiar with the tank-like construction of the Series 1 f/3.5 lens, it will be clear that the addition of the 2x converter will make it very difficult, if not impossible to shoot hand-held. Adding a Polarizer will cut us down 2 more stops to about f/16. Cost should be around $125-$150 or so for the lens and tele-converter setup.

# A lighter mid-range such as a Kiron 80-200mm f/4.5 zoom (55mm filter size) with a 2x tele-converter. As before, the tele-converter will lose 2 stops, and we will end up with around 400mm f/8. The assembly is not as heavy as the Vivitar Series 1, but still unwieldy. The same filter factors apply. Cost approx $150

# A third possibility is the Zuiko 300mm f/4.5 prime (72mm filter size). Now, the 300mm falls into the super-telephoto range, and it is built compactly enough that hand-held photography is possible. Add a 2x converter, and you have a 600mm f/8. Hand-held is out of the question, though. Same filter factors apply. Cost varies approx $350 for the setup.

# Vivitar used to make a 75-250mm f/3.8-4.5 zoom (62mm filter size). When coupled with a 2x tele-converter, gives us a 500mm f/8 at the upper end of the range. Too big for hand-held photography, and the same filter factors apply. Cost approx $125-150 for the setup

# Tamron made a 60-300mm f3.8-5.4 and Tokina made a similar 60-300mm f/3.8-5.6 that could be coupled with a 2x tele-converter to give us an 600mm f/11 at the upper range or an approximate 500mm f/8. Still huge though, and no hand-held. Same filter factors apply. Cost varies, approx $150-200 for the setup.

Of course, if we are able to focus using the ground glass portion of the focusing screen (if you’re using a OM-1 or OM-2, you can get a 1-10 matte focusing screen, which has grid lines but no center prism.) and are willing to use a proper support/tripod, the above combinations will permit stopping down to at least f/22 or lower.

There are Digital options as well — if you have a Olympus E series DSLR and the 4/3 to OM adapter. In the Olympus E series cameras, the smaller CCD size (12mm x 18mm) affords a digital conversion factor or 2x compared to the 35mm format (24mm x 36mm), so any of the above 35mm lenses focal length will effectively be doubled – for example the Zuiko 300mm f/4.5 when fitted to the Olympus E-500 will be a fast 600mm f/4.5, and the Vivitar Series 1 75-210mm f/3.5 lens will be a 420mm f/3.5. By the same token, the 500mm Mirror will become a massive 1000mm f/8. But that’s only if you have already made the considerable investment in a DSLR. I’m not sure what kind of results we would get with hand-held photography, although I am sure that the image stabilizing technology makes life much easier. The 2x conversion applies only to the 4/3 (Four-thirds) lens system and Olympus E series cameras. The Sony Alpha (aka Minolta) has a 1.5x digital conversion factor. I am not sure what the Canon and Nikon digital conversion factors are. Perhaps 1.4x??. Here’s a beautiful example of what you can do with a 500mm Mirror with a 2x tele-converter on an Olympus DSLR. This is 2000mm equivalent Handheld!!

One other advantage we have now that the photographers in the 70’s and early 80’s did not have (back when the bad rap started) is better FILM. We have much better emulsions that provide high quality images with 400 and even 800 ASA film. So if you have been hesitating with respect to buying a Mirror lens, give it a try. Keep an open mind, and don’t compare it with its much more expensive counterparts and I can assure you that you’ll be surprised. Look for a good deal, and take the plunge. Maybe you know someone who has a mirror lens they will let you borrow for a few days. Load your camera with 400 or 800 ASA color film and go shoot. Perhaps go hiking or even birdwatching. Don’t worry about filters. If needed, you can use some simple post-processing software tools provided by Picasa to make minor adjustments.

Maybe it won’t be professional quality but at least you will not lose another super telephoto opportunity. And if you’re happy with the results, that’s all that matters. Who knows? Like me, you might fall in love with the doughnut bokeh. And by the way, mine is a very ancient, beat-up looking Soligor CD lens. Check out the setup below. 😀

---

500mm Mirror #1

500mm Mirror #2

500mm Mirror #3 – check out the bokeh

500mm Mirror #4	500mm Mirror #5
500mm Mirror #6	500mm Mirror #7
500mm Mirror #8	500mm Mirror #9

Photographed with an OM-2, Soligor 500mm f/8 Mirror lens, 1/125 sec, f/8; Fuji Superia 400 film. For the curious – here is my camera and lens setup. I am using a collapsible rubber Mamiya 77mm screw-in lens hood to protect the mirror lens from flare.

OM-2 and Soligor 500mm set-up #1

OM-2 and Soligor 500mm set-up #2

Here are the related Posts:
Cheap Super Telephoto Lenses Part I
Cheap Super Telephoto Lenses Part II
Cheap Super Telephoto Lenses Part III

---

text and images © 2007 ajoy muralidhar. all names, websites, brands and technical data referenced are the copyright or trademark of their respective owners.