Do you really need an Alpha 900?

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If you are on the verge of making a decision, I’m here to help your think clearly – even if it means breaking some cherished behaviour patterns. I am going to help you think of the Alpha 900 not as a logical progression from the 700, but as a different camera system entirely.

For over a hundred years, camera makers have tried to reduce the size and weight of equipment; to make focusing errors disappear, and pictures become sharper without needing a tripod. In the early years of the 20th century rollfilm began to replace plates; in the 1930s 35mm film took over from rollfilm, though it was to be 40 years before professional use matched amateur enthusiasm. For the snapshooter, sub-35mm formats like half frame, 110, Disc and the Advanced Photo System (APS) then attempted to supplant the full 24 x 36mm 35mm format.

The Vectis S-1 SLR – a film format, in its non-panoramic form, called APS-C . That gave its name to the sensor size Sony call DT and Nikon call DX.

When digital SLRs arrived, many formats were tried out from full frame to quarter-frame but something very similar to the APS-C (Classical) format proved economical to manufacture and offered an acceptable trade-off when used with existing lenses. Though it only used the centre 16 x 24mm of the full 24 x 36mm coverage, this central zone was and remains a ‘sweet spot’ getting the best sharpness from many optics.

Losing recent advances

The loss of wide angle coverage which resulted meant that new lenses had to be designed just for this format, though the mount fitting was inherited from existing systems. This was a challenge because the back focus distance involved demanded extreme retrofocus zooms. But it also improved the results, forcing the lenses to be more ‘telecentric’ and project the image from a greater distance on to the digital sensor. This, for technical reasons, improved the all-round quality centre to edge.

The Sony SAL 18-250mm – a DT lens with a range that has never been achieved on full frame.

While SLR bodies did not shrink to match the 0.66X reduced imaging area (1.5X factor), they could be made as small as any film body used to be – or beefed up and given professional features like 5 frames per second motordrive, which you will find in the Sony Alpha 700. Sensors improved to the point that unheard of ‘fast film’ speeds produced fantastic results. ISO 400 was no longer fast; ISO 1600 is an everyday setting and ISO 6400, never achieved by any film as its normal rating, arrived for action shots. Low light is best tackled using lower settings, but that’s another subject!

The Alpha 900’s big mirror hides a large focal plane shutter – over 35mm size – and full 35mm size sensor.

Now, along comes the economic possibility to make full frame digital sensors just five years after the first wave of consumer-enthusiast ‘APS-C’ format DSLRs. In that five years, whole ranges of lenses have been developed offering unprecedented zoom ratios and features. There never was such a lens as a 24-160mm* or a 42-450mm* for film, but digital SLR users quickly got used to just this kind of range. Once, if you bought a typical zoom like the Minolta 24-105mm D you thought it a big step forward to get close-ups at 0.18X – that’s less than one-fifth life size, on full frame. The digital replacement, Sony’s CZ 16-80mm, manages 0.24X which is better than one-quarter life size, but it does that on a 1.5X factor format – meaning it’s the same as a 24-120mm (more range) focusing down to capture one-third life size on film.

The comparison is 0.36X versus 0.18X and that means the digital lens, on the digital format, actually shoots close-ups at twice the output magnification (for the same size print, in case any pedants are reading this).

*A 16-105mm and 28-300mm when used on APS-C

Depth of field

Throughout the domain of the APS-C DSLR, the small sensor format has transformed things. For the same angle of view, a full frame film camera needs 1.5 f-stops more stopping down to get the same depth of field (sharpness in depth). So, a shot which would be sharp enough from foreground to background at f/8 on an Alpha 700 must be shot at f/13 on full 24 x 36mm.

This shot was taken at f/11, 60mm focal length. Click it to open a full 24.6 megapixel image and see just how limited the depth of field is when examined so closely!

Is that a problem? Not on its own, but it also means a shot taken at 1/125 (which freezes most facial expressions and slight body movements, if not action) would need to be taken at 1/40 instead. There is a big difference. Wind moving foliage, people walking, many slow movements in the real world are sharp at 1/125 but blurred at 1/40.

So, to regain the benefits which have been conferred by the small digital sensor, any full frame digital sensor really needs to offer equal quality at three times the ISO sensitivity figure (or 1.5 stops), just to enable the user to get back to the same actual depth of field and motion-stopping shutter speeds. This means a full frame DSLR must be as good at ISO 400 as an APS-C model is at ISO 125.

This shot was taken at the same place, but with a focal length of 22mm and aperture of f/25 – an extreme case of stopping down, with 1/8 shutter speed and tripod. Click to view the full size version.

Should that be pixel for pixel, or allow for reducing the image size? I think it needs to be absolute not relative. There is not much point at all in full frame unless you can genuinely make a bigger print or a sharper print, which means using extra pixels if offered.

There is only one good reason for wanting full frame other than this – if you actually want less depth of field. If differential focus effects, isolation of a portrait subject from a background for example, are important to you then the Alpha 900 will deliver this more readily than the Alpha 700 (or other APS-C model) under similar flash or lighting conditions.

The effects of differential focus work beautifully with colour. Since this flower was blowing around and vibrating, I need a fast shutter speed (1/250th) with the 100mm macro at f4 after sunset. I underexposed at ISO 200 and pushed the processing from ARW using ACR 4.6, by 2.3 stops plus extra brightness, vibrancy and clarity (but not saturation). It’s a noisy result without anything more than ACR default NR but I like the colour and the bokeh (remember it is effectively at ISO 1000). The A900 viewfinder makes shooting this type of subject a real pleasure even in poor light. Click to open a larger version.

The focal length factor

If you buy into the Alpha 900, you are committing yourself to a whole different range of lenses. If you buy the forthcoming 70-400mm zoom, it will not offer the same reach the 70-300mm model does on the A700. You have the option to use a cropped APS-C mode, which produces an 11 megapixel file, or to crop any full frame as you wish. That in effect more than restores your telephoto reach.

One benefit of full frame – if you don’t keep your subject dead centre in the frame, you can crop in and get as big an image as APS-C. Click on the shot for the full size 70-200mm SSM image. 1/1000s f/5.0 at 200mm, ISO 400.

But if you are shooting with a long lens and want 24.6 megapixels, the cost in size, weight and money may be prohibitive. The difference between a 200mm f/2.8 and 300mm f/2.8 shows this perfectly. The Minolta APO G 200mm f/2.8 weighed just 790g, was 135mm long, and took 72mm filters; the 300mm f/2.8 APO G of the same period weighed 2310g, was 240mm long, and needed 114mm filters (but a rear 42mm filter slot was provided).

The 200mm f/2.8 covers exactly the same field of view, at the same maximum aperture, on the Alpha 700 as a 300mm f/2.8 does on the Alpha 900. The 200 focuses to 1.5m; the 300mm can’t get any closer than 2.5m and at closest focus, produces a smaller subject scale than the 200mm does. Fortunately the last Minolta and current Sony APO G (D) SSM version can manage 2m and now beats the vintage – discontinued – 200mm for magnification.

My 17-35mm KM D lens is restored to a genuine 17mm view – and through the large bright finder, precision composition is made easy. ISO 200, f/11. Click on picture for full size.

At the other end of the scale, the wide-angles, your choices are limited. A probably superb CZ 16-35mm f/2.8 will be available in January 2009 at around three times the price of the existing 11-18mm which serves (though lacking in speed) for APS-C. And, if you consider the 10-20mm Sigma useful on APS-C, you could simply opt for the 15-30mm Sigma on full frame; it’s exactly the same range and slightly faster! Or you could choose the 12-24mm Sigma, which has no 8-16mm equivalent for APS-C.

The Alpha 900 looks entirely at home with the 16-105mm SAL DT, but in practice, it’s not… practical!

Should you try an APS-C lens on the A900? Sony say it will give incorrect exposure metering unless you use centre weighted or spot. I say that you really can’t see the APS-C frame markings in the viewfinder against most subjects. For action shots, you have little chance of being aware of the frame zone. And you can’t turn the cropping off (except with some independent lenses which the camera fails to recognise as needing a crop), and the raw file is cropped too.

For walkaround zooms, you must look at rather older designs – the 28-300mm Tamron in place of an 18-200mm or 18-250mm. Is it really worth the compromise? The whole point of walkaround zooms is convenience, and the Alpha 900 increases size and weight. The resolution and overall performance of a 28-300mm may not fit well with the full frame.

With macro lenses, the 1:1 aspect is again changed back to where it was pre-APS-C. Of course, it is still 1:1, but relative the print size the magnification on full frame is less impressive. Remember, 1:1 on the Polaroid 20 x 24 inch camera is a head and shoulders portrait – and 1:1 on a video camera is the head of a butterfly. Macro is a field where the super-bright, large viewfinder of the Alpha 900 really pays off and 24.6 megapixels can be very useful, but if you want to match the stunning closeups people have been getting on the Alpha 700 and Alpha 350 you must add an extension tube to your macro lens.

The 100mm f/2.8 Macro AF works well on the Alpha 900, but on the 700, only half this area of subject would have formed the entire picture. Click on picture for full size.

However, I should not play Devil’s Advocate all the time. The large finder of the Alpha 900 also transforms wide-angle views with lenses like the 17-35mm Konica Minolta D, to the point that you feel you have regained true wide angle composition. No matter that the 11-18mm at 11mm is just the same on the Alpha 700; it’s small, vague and dark as a compositional view compared to what you see through the A900. The 900 returns the 16mm f/2.8 fisheye lens to its true coverage and look.

It allows lenses like the Sigma or Tamron 14mm f/2.8 designs to do their job, as with Sigma full frame ultrawide zooms. Lenses like the 200mm Apo G f/4 Macro from Minolta, which is almost too long for comfort on the Alpha 700, become far more friendly. The 50mm f/1.4 is a standard once again, the 35mm f/1.4 and 28mm f/2 get their status back; so do the 28mm f/2.8, 20mm f/2.8 and Minolta 24mm f/2.8. The 85mm f/1.4 designs frame better for portraits and the 135mm f/1.8 and STF lenses can at last be used in a normal sized indoor studio.

My 50mm f/1.4 restored to its normal view! This is the Alpha 900 used for a 13 megapixel direct in-camera JPEG at ISO 1600, with +1 over-ride set to get the correct tonal quality for the shot. Sharpness (and all other parameters) set to 0 default using Standard sRGB style. Auto WB. High ISO NR set to Normal. Since this was shot with cRAW, it is a FINE quality JPEG not Extra Fine. Click to image to see the JPEG.

The flash dilemma

If you use on-camera flash, or the wireless system, the Alpha 900 will cost you real money. It has no built-in controller for wireless remote flash units, and no onboard flash. The affordable HVL-F42AM makes a decent if bulky substitute for the missing pop-up, but can’t control remote flash. The only flash which will do so is the HVL-F58AM, a superbly made and presented bit of gear but one of the most expensive camera top flash units on the market.

Your existing Minolta 3600HS(D) 2500(D) and 5600HS(D) guns, or Sony HVL-F36AM and HVL-F56AM equivalents, can be wirelessly controlled by the HVL-F58AM but only at their native power values. No controllable ratio can be set. Nor can they be assigned into ‘Groups’, a function used by ratio-lighting setting. The HVL-F42AM can be, and so can additional HVL-F58AM guns. Examine the possible costs, and you will realise that one of the expensive 58 guns is sacrificed to act as an on-camera controller from the start. It would be easy to spend £1,000 setting up a two-head wireless flash kit for the 900.

With reluctance I’ve bought a 58, because I have a 42, 56 and 36. The 58 will be most useful for solo flash on camera work, bounced light for groups, and so on. The other three can form a reasonable ‘studio’ with some control possible via the (wasted) 58 in controller mode.

But – I have also found on eBay a little Minolta 2000i flash. It’s incompatible with digital TTL and has no manual controls, so it will always fire at full power. That’s GN20 and coverage for a 28mm lens only. It has a low profile, unlike the digitally compatible Konica Minolta 2500D flash which is a mini bounce model. I’m quite capable of working out manual exposures for GN20 (f/2 at 10m ISO 100, f/4 at 5m, f/8 at 2.5m, f/16 at 1.25m, f/22 at 0.75m). For £14 it will make a neat standby in a pocket.

And then there’s the filesize!

The final question, once you appreciate that moving up to an Alpha 900 also means living with more assertive shutter-mirror action and a larger body to handle, is all about what it consumes and what it needs to support it.

First of all, Sony claims 880 exposures per battery charge. I believe this is an error; it is more than the Alpha 700 (750) despite running twin processors and having exactly twice the data to push through. I have not yet managed much over 250 exposures per full charge, shooting RAW+JPEG, and see little chance of reaching 880 under any circumstances.

A detailed image like this can be 24MB just an an Extra Fine JPEG. As JPEG+RAW, this one used over 40MB of card space – 25 shots per GB. cRAW compression saves 12MB per shot (24MB file versus 36MB file). This shot shows that at f22, the minimum aperture possible, diffraction is not ruining a 17mm view on the A900 with its relatively large pixel pitch. The point of focus is easily found, in the first third of the boat where there is some rope above very sharply detailed textured boat floor. f22 is not enough to keep the prow sharp, or the background view. Remember, when viewing this on a 96dpi monitor, you are viewing a ‘print’ over five feet high close up! Click image to go to the full size file.

You will need exactly twice the card space for the same number of shots. So, if you use 4GB cards and find they fill up on a typical day, you’ll need 8GB. However, the Alpha 900’s very clear and large viewfinder helps you avoid poor framing or timing, and the general feel of the camera promotes craftsmanship rather than random snapping. If you can begin to put yourself more into rollfilm technique mode, you may even end up being more economical with the gigabytes.

Bridge will create thumbnails for raw – with Alpha 900 images, the process of creating these (in similar programs too, like Lightroom or C1 Pro) to high quality is longer than for smaller image sizes.

Finally you have to process and archive your work. Programs like Bridge and Photoshop use hard disk space for scratch memory and cacheing previews; you can be sure that doubling the data size of every shot converted to a thumbnail, previewed to high quality, and processed in Photoshop will double the workload on your computer processor and the demands on temporary or cache hard disk space. Even if you have an efficient setup with 3-4GB of RAM available, it’s the reading and writing times for the original images and everything associated with them that will slow you down.

If you have a recent computer system, all will be well. But you may have a slightly older system which had coped perfectly with A100, A200, D5D, A700 and even the 14.2 megapixel A350 files. Start work with the A900, and it just loses that edge. So, be prepared to have to upgrade your PC or Mac in addition to the relatively minor investment needed in external HD drives for archiving files.

The package

All these factors add up. Each one alone is not too hard to reconcile with your plans for future DSLRs – but when you take them as a bundle, it can be a heavy bundle! I have not even considered the possibility that to get the most from the Alpha 900, new Sony and CZ lenses may be neeed. Though the body costs £1,800 a set of 16-35/24-70/70-400mm will add £3,000 and your ideal flash kit £1,000 more. Computer upgrades could cost you another £1,000 and so could that HDTV you covet for viewing the images at their best!

If you already own an Alpha 700 with 11-18mm/16-80mm/70-300mm you will gain one or more f-stops of aperture across much of the range, and some genuine telephoto reach. You will lose the great benefit of APS-C, a top grade general purpose zoom offering a far more useful long end than the 24-70mm does on full frame. Don’t imagine the 24-105mm can do this job; I have one, and there is no comparison. The 16-80mm CZ on APS-C is a much better lens all round than the Sony SAL 24-105mm on full frame.

The 70-300mm G SSM is a wonderful lens – free from CA and sharp corner to corner wide open – but it’s essential a consumer grade design, with distortion even at 200mm turning the horizon into a dish. Click to view the full size file.

But you may already own a 24-70mm CZ; you may have a 70-300mm SSM G which will do a moderately good job on APS-C, though with a ‘consumer’ level of distortion and vignetting. Like me you may have older 17-35mm or 28-75mm lenses and find that they work well; or real vintage stuff like the 70-210mm f/4, original macros and 50mm f/1.4 which perform even better. The Alpha 900 could reward you for keeping or acquiring such lenses by showing you what they are really designed to do.

Point of no return

This article is intended to stop you in your tracks, but not to stop you entirely! I have to own and use an Alpha 900. I could not run this website or Photoworld magazine without doing so. I also have to keep my earlier equipment. The A350 sits there with a 16-80mm on it now. The A200 has the 16-105mm. The A700 has been passed to Shirley who prefers one lens to do everything, so it now has the 18-250mm.

So what do I do? I use the Alpha 900. I use it because once you have done so, there is no going back. Buy it, and your APS-C gear will be forgotten. Your cherished CZ 16-80mm won’t get a look in, even if you can’t afford a CZ 24-70mm and end up with a budget alternative like the 28-75mm D on your new full-frame. The accuracy of the focusing before you even consider using the micro AF adjustment, or try manual focus, will make you unwilling to return to the vagueness of the APS-C focus points again.

After making a 20 x 16 Epson Stylus Pro 3880 print on Ilford Galerie Gloss premounted exhibition board media, I realise why I will be shooting with the Alpha 900 in future. 17-35mm Konica Minolta f/2.8-4 D lens at f/22; lighthouse added from a second shot, as its real position is to the left outside this composition. Click the image for a full size file. You re welcome to download and print this if you would like to see for yourself!

You will keep using the Alpha 900, and you will probably travel with it even if at first you put your lighter and more versatile kit aside for vacations and trips. Commonsense tells you that the extra depth of field from the APS-C format makes it much better for sports, family, pets, theatre, concerts and all those 90 per cent of your images where a little more in sharp focus can only help. But you’ll use the Alpha 900 instead. You may even end up with worse pictures sometimes, and be aware of it, but still unrepentant!

To conclude – you will have moved on to a different system. It may still be Alpha, and the changeover may be smoothed by Sony’s attention to keeping memory card types, battery, remote controller, cable connections, filetype, lens compatibility and the user interface consistent.

No skilled photographer who takes the step up to the Alpha 900 and full frame digital will regret it – but you need to take that step in full awareness of everything involved.

– David Kilpatrick

Unique features and key points for the Alpha 900

Full frame 24 x 36mm capture
Good compatibility with many older Minolta and Konica Minolta AF lenses
100% viewfinder at 0.73X magnification (2nd largest of all DSLRs made)
Fully corrected eyepiece allowing clearer vision of the focusing screen
20% brighter viewing image than any other DSLR
24.6 megapixel image, the highest resolution of any DSLR
5fps continuous shooting, the fastest for any DSLR over 18 megapixels
SteadyShot image stabilisation through sensor piezo movement applies for all lenses
Oversized reflex mirror gives maximum brightness and coverage for tele and macro lenses
Shutter speeded 30 seconds to 1/8,000 with X-sync at 1/250
PC X-sync socket
Alpha dedicated wireless flash system with channel, ratio and group control possible
A genuine 5 frames per second capture rate (tested)
True mirror lock-up mode, 2 second m/up timer and normal 10 second self timer
Viewfinder eyepiece backout blind
Intelligent Preview first stops the lens down for screen depth of field viewing then shows an adjustable capture on the LCD screen
Top LCD provides shooting settings summary and changes context for adjustments
Three Memory positions on the simple PASM/Auto main mode dial, like the Dynax 7D
Two memory slots with extremely fast read/write on the main CompactFlash drive
1920 x 1080 HD output and 16:9 capture mode
True cropped RAW mode for APS-C lenses (11 megapixels, 1.5X factor)
Magnesium alloy body
Weathersealed with gaskets on all controls and labyrinth design for card and interface doors
Capable of full style adjustment range in both AdobeRGB and sRGB modes
Extra Fine JPEG mode available as an alternative to raw
USB tethered shooting software supplied for both Mac and PC
Full image browsing and raw conversion software supplied for both Mac and PC
High ISO NR includes OFF option as well as Low, Normal and High


  • Great Article…

    I got an A350 earlier this year and loved it, when i saw then a900 i also wanted one of those, but not at the orginal price. Then in October i seriously decided to get one. I tried all my lenses SAL16F28 SAL1680Z SAL70400G and all seem to work great. But at $AU3799 best price I still could not justify it, i was lucky to find one on eBay for $AU2200 just a few months old and when it arrived it had less than 500 clicks on it.

    On my first shoot it was then i realised that the SAL1680Z is cropped to APS-C mode and there is no override. So i have a Minolta 24-105 AF D as a stop gap till sony brings out a 24-135Z.

    As for the battery i have managed to shoot 650+ shots in one sitting (wedding) then a week later shoot another 200+ shots without a recharge. The battery was down to 1% and still managed to take a 5fps 10 frame burst before i turned it off, but i’m sure it could still take a few more.


  • Great article. Quite a bit to think about. One correction, however. You stated, “There never was such a lens as a 24-160mm* or a 42-450mm* for film…”, but the Tokina AT-X 24-200mm f3.5-5.6 was made in A-mount during film days. I have one right in front of me. Not a bad lens, not stellar, but not bad. Great walk-around lens.


  • David – Appreciate the article and the numerous pros and cons. My a900 is in route and I was toying with the thought of parting with my 7D. I think I’ll try to find a way to keep for both formats for now, seeing that their may be some advantages the 7D can bring that the A900 can’t.


  • Good article and fair warning for those who are seduced by the power of the “bright” side.
    I have been using Minolta since the first autofocus 9000 days (I resisted the 7000 and waited), my last film camera was the 7xi and jumped on the digital 7Hi 5 meg when it first came out.
    I have enjoyed getting back into the SLR feel when Sony came out with the A100.
    I thought I was getting an “upgrade” by getting the 900 but NOOOO. You are actually going for a full blown NEW system.(Think Sir Alec Guiness waving his Jedi hand)
    You WILL put up with the cost and weight plus all the things Dave mentioned (but I must point out I am like Hobbitofny in my preference to shallow depth of field because my main subjects are people.
    Dave obviously prefer living on the “wide” and scenic side.
    You WILL let your alpha APS-C collect dust even when the 18-250 is SO convenient.
    You WILL start to acquire 24-70 2.8, 70-200G 2.8 and the upcoming 17-35 2.8 once you realize what you saw through that magnificent viewfinder you can actually capture in high res file and if you have means to printers like the Epson 4880 or Canon ipf5100, you WILL make prints like Dave and remembered why you picked up that Canon A-1 or that Hasselblad 500C/M so many years ago.
    I AM contemplating something like the Canon G10 on days when my shoulders refuse to co-operate but then again, this is the Alpha forum.

  • The one thing I miss about medium format is the shallow depth of field. I would not shoot the full frame A900 at stopped down more. I would leave it. Some subjects need the greater depth of field. However, when I photograph people, I prefer they are sharp and the background is not fully sharp. It tends to help the people standout in the photograph. The shorter depth of field is welcome for people. Now travel images of locations need more depth of field. So it is one less stop.

  • Excellent review as usual. I didn’t realise that a full frame sensor meant at least one stop less for shooting and that could make a differnence for me in deciding whether to upgrade from my A700, or not – depth of field and all of that.

    My usual ISO is 200, if I used an A900 at ISO 400 to compensate, is the resulting shot still of superior quality to the A700? Thank you.

  • Ooh – I shouldn’t have read this… My lenses would match it, my back is still strong enough to carry it, my shooting style probably would match it…

    Just for a hobbyist with a family I see no way to justify it. And therefore I will not take a look through the viewfinder.

    Or will I?

  • Thank you David for this wonderful and important article.

  • Thanks David, just to clarify the Minolta 1800AF does not have a standard (non Minolta special) mount, but instead the first generation Minolta mount for the 7000 etc. I need to get hold of an FS-1100 (or possibly a HK clone).

  • Yes, the FS-1100 will trigger ISO mount flash. I tested it up to 1/250th, perfect. And guess what – I realised, after testing 1/320th and getting a slight edge shadow, that using the APS-C crop might just allow faster synchro-sun pix. It does. With a manual flash using crop mode 1.5X, you can sync safely at 1/400th of a second.


  • An article that ‘needed’ saying, but no real surprises – and not something I’ll be worrying about for a year or so [providing I don’t get a look through that ‘finder!]…

    …slightly O/T, but

    “The A200 has the 16-105mm. The A700 has been passed to Shirley who prefers one lens to do everything, so it now has the 18-250mm.”

    Any chance of some comments from Shirley as to her likes/dislikes following the change, since you’ve previously described your differing shooting styles – just wondering how she’s getting on with the A700 compared to the 5D/A100/A200’s I believe she’s mainly used in the past…


  • David, I’m a little confused now, nothing new there 🙂

    Are you confirming that the FS-1100 will work?

  • “Q: I have an old Minolta Program Flash 1800AF – it has the old ISO flash mount, can i use the FS-1100 adaptor to use this flash (on full power) with the A900? – I would have tried it with the A700, but didn’t have the adaptor.”

    I have just tried the earlier 118X Auto Electroflash with external sensor – I have a brand new one still from the old ex-KM stock – and it works perfectly. Even gives perfect exposure using its auto function at two different f-stops or works on manual! The 1800AF will work on full power.


  • As always a detailed article on the chosen subject. I think you really bring together the differences and the overlooked changes with a full frame digital camera.

    But despite all of this, everything still cries out YES I NEED ONE! Even though having read your article the logical and scientific choice would be to look at an A700 to replace my Dynax 5D, and certainly the accounting view given you can now buy three A700 bodies for the price of an A900.

    I would agree with the comments above, that once you look through the viewfinder you will want one, because its such a brilliant feature that you will use on *every* picture you take with the camera. Who needs live view!

  • Q: I have an old Minolta Program Flash 1800AF – it has the old ISO flash mount, can i use the FS-1100 adaptor to use this flash (on full power) with the A900? – I would have tried it with the A700, but didn’t have the adaptor.

  • Thanks for the article David, as you know I was in the situation you described, having an A700 + APS-C lenses (and 3600HS-D flashes). I do realise that I will give up quite a lot of what was good with that setup going to the A900, however if I find I need a lightweight APS-C again in the future, I can always pick one up fairly cheaply, as they become even less expensive over time, even new. I’ll regret selling the CZ16-80 no doubt, but I want one day to get 24-70.

  • I don’t really bother that much about 27mm versus 28mm, as on a Canon the same range is 28.8mm equivalent – but even that is not accurate, the 1.5X and 1.6X factor figures are not precise and depend on the actual sensor. The Sony factor is 1.538X on the short side, which is closer to 28mm than 27mm – but 1.485X on the long side, which is 26.73mm. Since for full frame zooms, the makers are allowed to quote 1mm short of the true focal length for film formats and to round down, a 26.73mm lens could be claimed for sure as 26mm in traditional terms.

    What is interesting is that the 16mm versus 18mm etc on digital cameras is FAR more accurate than the standards which used to apply for lenses made for film cameras. The inaccuracies come from surprising differences in actual sensor image areas. One great thing about the Alpha 900 is that it has a 24 x 35.9mm image, not something vaguely close to 35mm. That’s a better tolerance size than the standards for 35mm film gates.

    Minolta called the lens on the Dimage 7/A series ’28mm’ by assuming you must crop the frame to 35mm shape to work out the equivalent. It is of course much wider, and if you crop a 35mm frame to 7/A shape (3:4 ratio) the 7.2mm lens is clearly equal to a 24mm.


  • I’m totally agree with you, the best warning we can say to a APS-C DSLR USER is to never tried the A900 ! or even to not to much look at some jpeg examples on the Net. As a Minolta old lens collector … this was my worst day of the year when i saw the A900 on pre-order in Canada. Even with no money in bank … i was completely unable to don’t order the A900. All my old lens was crying in the closet, like people who has never eat :-).

    The best things i can recommend to APS-C user having some Full frame lens, just go on Ebay, and buy a old Maxxum 7000. This Camera has a very bright and good view finder. If you are like me on the first time i have do this, you will tell you, HO MY GOD ! I CAN ISOLATE AND FEEL MY SUBJECT. For me, this was the first time i have decide to invest only in Full Frame lenses. The only lens i have on my bag as APS-C lens is the trusty 18-200mm Minolta D lens (Not so sharp, but no to bad too 🙂 ).

    Very good article David ! I have read it two time, and i think i will read it again before bed :-).


  • David, excellent article! Just a minor correction:

    “There never was such a lens as a 24-160mm* or a 42-450mm* for film, but digital SLR users quickly got used to just this kind of range.”

    The Sony 18-250mm is 27-375mm equivalent. Only 1mm, but at the wide angle end 1mm is noticeable. I have this lens on my A700 and I am still pretty happy with it. I got it after you were probably the first to point out that it (you originally wrote about the Tamron version) was so surprisingly good.

    I have been using SLRs/DSLRs for 35 years and I am still amazed at having a 27-375mm lens that is pretty darn good. 🙂 Along with my Sony 11-18mm (16.5-27mm equivalent) that gives me 16.5-375mm in two relatively small, light lenses for backpack travels. I also carry the small, light Minolta 50mm f1.7 for the occasional times when I need something even faster or want much more limited dof.

    Of course, the A900 looks fantastic, but a few months ago I decided I wouldn’t be getting one. Since I used 35mm SLRs for years I know about the A900 advantages you have written about, but I also know the disadvantages. The main thing though is the increased size and weight and, of course, the quite large additional cost in total to go for one. Over time, I may decide that I will get a full-frame DSLR, but not now.

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