Minolta RD 175 - Retro Review
The Minolta RD-175 is the oldest working digital-modified film SLR that I have managed to find so far. The story of using this, now thirty-year-old, machine has been a long and rather fun experiment for me. Although its "reduction optics" drastically diminishes the camera's ability to render the lenses depth-of-field as intended, it is still a fascinating piece of digital history.
Minolta RD 175 & AF 35-70mm f/4 lens
(Taken with the Sony A9 + Tamron 90mm f/2.8 Macro)
Key Specifiations
Date:
$ (inflation):
Sensor:
Resolution:
Burst:
DR Stops:
Sync:
SS:
AF points:
Video:
Live-View:
ISO:
OVF:
LCD:
Memory:
Weight:
Battery:
1995
$9,999 ($21,000)
3x CCD (2x crop)
3x 0.38mp / 1.75mp
0.5fps
<6 (8bit)
1/90th
2s - 1/2,000th
1 (15%)
No
No
800
1.04x / 90%
None
PCMCIA type III
1,200g
300 (NP-500H)
History
The Minolta RD-175 was launched in 1995 in collaboration with Agfa, who called their model; The "ActionCam" (1996). The market was small back then, Nikon's E2/E2s using a similar reduction optics and the Kodak DCS 420/460 using a more conventional sensor arrangement. These cameras were priced between $10,000 to $28,000, of which the Minolta was on the low end.
Sensor
Although the crop factor suggests that this has a roughly micro four-thirds sized sensor, it's actually far smaller. It's about half the size of a modern smartphone sensor, or one twenty-fifth the size of full frame. The reason for this disparity is that light from the lens is split via a prism and magnified on to three separate sensors. If you're thinking, "oh wow, one sensor for each colour? That's a cool solution to the Bayer pattern", don't get too excited. Two of them are used for green (66%) and the other sensor shares the capture of red and blue. So not only does this camera have issues of colour alignment, but they're not even elegantly organised.
Tokina 19-35mm | Raw Therapee
Build
Based on a Minolta Dynax 500si Super film camera. This is a cheap camera, covered in cheap plastic, housing a first generation reduction optics system that extends the back of the camera in a rather clumsily way. Its bulk sticks out awkwardly in pretty much every direction, making it almost impossible to hold in your hand while walking, even with a small lens. However, it is so large that the weight distribution makes it feel less heavy than it was on paper. It's difficult to imagine this camera as ever appearing elegant, but it's not like Kodak's DCS 420 wasn't also a bit of a monster.
Software
These .MDC files will not open in Adobe, Affinity, Capture One or even Dark Table, so if you can't run the official software and are looking to do something with the files, then my initial success was through RAW Therapee. Although it will open the files, it doesn't work out-of-the-box. First I had to go into the settings and add the .mdc format to the list. Then the files open, although the latest version (5.11) has a bug where the images all look massively overexposed. Dropping back to an older version (5.8) worked for me. I find this program rather difficult to get used to, and not just because of the bug, so I gave up on it in the end.
I got much better results from the free edition of PicaJet, simply using it to export all the images to .Tiff files. I imported all the .MDC files, selected all and batch converted them. Then used Photoshop & Adobe Camera RAW to unstretched the images, de-noise, sharpen, edit colours, add contrast etc.
Astonishingly, The original RD-175 software is still available on the offiial Konica Minolta website. It's only officially supported on Windows up until 2000, but it worked for me on the latest Windows 11 Pro (24H2). It allowed the .MDC files to be exported into something more usable (tif, bmp, jpg) while giving sharpening and CA removal options. It's pretty basic, but the Chromatic Filter worked pretty well, files are in the correct ratio, you can process everything at once and the dynamic range was better mapped into the 8bit space. I wouldn't recommend applying the sharpening in here (modern software will do a much better job), but this is a good start.
Sony DT 50mm f/1.8 | Pixel Ratio
As the text on the front suggests; The Minolta RD-175 has three separate CCD sensors. Each of these sensors measures 6.4x4.8mm and can capture 0.38 megapixels (760 x 480). The final resolution was then interpolated up to 1.75 megapixels, but that's only if you use the original software. Both PicaJet and RAW Therapee output these images at 1.5mp, but to correct the ratio you will need to raise the vertical resolution up to 1146 pixels, which will then take the final resolution to 1.75mp.
The first three examples below show the direct output (no exposure or colour adjustments, no noise reduction or sharpening) from each of the three pieces of software that I found could export the .MDC files on a Windows PC. The last image shows the processed image using the export from PicaJet (my favourite output)..
Tokina 19-35mm | Software Comparison
Image Quality
Describing the image quality won't be needed, since it'll be clear from the tiny web pictures. You're not missing anything here. You can understand why people of the time thought that digital photography was not a threat to film. In hindsight, we know things would dramatically change pretty soon, but back then that wasn't so clear. In the early 90s, sensor resolution, dynamic range and camera speed sat squarely in the "inferior-to-film" camp. Between 1998 and 2008 we went from the Kodak DCS 520 to the Nikon D3X so things would soon heat up. In the seventeen years since then, image quality improvements have slowed to a crawl, and so photography innovation has shifted. Modern digital cameras have given us improvements like: High resolution electronic viewfinders with zero blackout, hyper-accurate and blazingly eye autofocus, stacked sensors, crazy burst speeds, battery life is improving again and all of this is being squeezed into smaller, lighter and totally silent machines, while lenses get sharper all the time (mostly). The RD-175 still "captures images", but the user experience doesn't easily compare to modern cameras. Its spiritual successor - the Sony A1 mkII is less than half the cost (adjusted for inflation) and absolutely insanely specified.
The RD-175's image quality is... pretty early. Although I managed to improve the images since Raw Therapee (PicaJet and the official exporter), the Noise, dynamic range, sharpness and colours are still some of the lowest quality that I have seen. If only I could hide this lack of quality with some nice shallow depth of field, but that option is not possible here (more on that in the next paragraph). ISO speeds are not changeable either, it's ISO 800, or ISO 800... that's it! These images look like an old phone from the very early 2000s (not a smartphone). Do you have a nice quality lens for the Minolta mount? It won't make a difference. The main benefit here is a feeling of nostalgia when you look at the images.
-
Miniscule CCD image sensors
-
Sensors in different locations (leading to poor colour alignment)
-
Added glass between behind the lens further reduces quality
-
RAW files no longer being officially supported (in the main editors)
Apertures
Like Nikon's E2 Digital camera, the RD 175 used reduction optics to refocus the light on to a much smaller sensor (or sensors in this case), but where the Nikon did that from a full (35mm) frame, the Minolta suffers a heavy 2x crop. Because of this system, just like Nikon, the Minolta has a limit on the minimum aperture (f/6.7). These two factors compound the issue of shallow depth of field (subject isolation), making the one aspect that could distract from poor image quality inaccessible. Effectively, you're limited to an f/13 aperture on any lens, and wide angles are extremely difficult to achieve.
Sony DT 50mm f/1.8 | RD-175 Exporter
Focusing
With only a single focus point that feels like it takes up a third of your view, there is no easy way of telling what the RD-175 is actually focusing on. This is made much worse by the viewfinder being incredibly small and poor quality, so your ability to see what's in focus is greatly diminished. The camera's inability to capture any shallow depth of field is somewhat of a bonus is this regard, just not a fun one. The Minolta 35-70mm lens you see it pictured with here, focused ok, although testing this on the Sony A900 showed this lenses quality is unsurprisingly not fantastic.
3rd Party Lenses
I also had a Sony A-mount 50mm f/1.4 lying around, so I tried that, and it too seemed to focus ok, but my experience went downhill from there. I bought a cheap Tokina 19-35mm Minolta mount lens because I thought it would provide a useful range (which it did), but the focusing was constantly grinding against the infinity distance, like it wanted to go further, showing red in the viewfinder and then giving up and going green after a second or so. Did this mean it was focused or not, I had no way of telling, but it didn't fill me with confidence.
Sony SAM Lenses
The two Sony DT lenses (50mm f/1.8 and an 18-55mm kit lens) would not focus on the RD-175 due to not having screw-driven autofocus. You don't get this compatibility issue with modern internal AF Nikon lenses when they're attached to an older AF camera, but I can understand why it happens. You also don't get the issue of the lens being locked up when attached to the camera. Although that only happened to me with the zoom, it confused me as to what was going on. Once I switched that to MF on the lens, I could focus manually. It was not easy to see what was in focus on the worst viewfinder I have ever seen, but at f/13.4, did it matter much? Probably not. Just guess the distance on the lens markings and you're all good.
Sony DT 50mm f/1.8 | PicaJet
Memory
The RD 175 was commonly used with a 131MB PCMCIA card, which could store 141 images. If you don't have one of these and can't find one, you can also use a PCMCIA adapter for Compact Flash cards. Originally, cards would need to be formatted inside the camera while it was connected to a computer, via the SCSI-2 connector. This can be extremely difficult 30 years later, even if you do have the cable (which I do), a SCSI connector on an old computer with an old operating system with the correct drivers (which I don't). The alternative option is to find an ISO image of the formatted card, which you can burn to a new card. There are posts online describing how to do this, but most of the links to those files have been broken for many years. I initially managed to get help from Ralf Jannke (of the digicammuseum.de), who kindly gave me a pre-formatted 64MB CF card. Later I found links to a 256MB image that you can burn to a larger card too, but if it wasn't for Ralf I would not have been using the Minolta for a while.
Hardware
Each part of the camera required different power. A 2CR5 battery controls the film camera elements, like focusing and shutter. Next is the main battery, a 1200mAh rechargeable for the digital elements. Lastly, there is a C2025 (watch) battery for the clock, to attach the correct date to the files. Although that last one is largely pointless, at least you can actually get to this battery, to replace it The same cannot be said about the early Nikon or Kodak DSLR models, which is unforgivably stupid. Surprisingly, mine came with two original rechargeable batteries, which both seem to charge and work fine. This is lucky, as I don't think you can find them any more. On the positive side, these are Li-ion batteries, which are quite small and yet still hold a reasonable charge today. This is surprising given how old they are! Making them considerably more friendly than the newer Kodak Ni-CAD and Ni-MH batteries.
Tokina 19-35mm | PicaJet
This camera has no rear screen, which means no reviewing of the images to see how your exposures or focusing was. Also, if you wanted to change any of the digital settings (including the date) it required connecting the camera to a computer via the SCSI cable. This is going to be extremely difficult today, unless you have (or buy) an old Windows 98 machine with the correct SCSI card.
Speed
The startup time for the camera being around one second, it's actually not too bad for the time. With a burst speed of up to 0.5fps, however (that's one frame every two seconds), this is in no way an action, or sports camera. Autofocus is another aspect that is slow, although with only a single large focus area, its reliability is the bigger issue, although at f/13 you could just set a hyperfocal distance and just deal with whatever image quality you get.
Buying Used
Being 30-years-old, the RD-175 is one of the oldest digital SLRs around that is relatively possible to get working. Compared to other models from the time, the Minolta (along with Agfa's "ActionCam" version) are not too difficult to find second hand today. I was very lucky to pick up one of these for around €60 that actually worked. If you're also looking to pick one up in working condition, make sure it comes with the charger and a couple of batteries. Also make sure the battery caddy is included. The trickiest element to get working today is a properly formatted card. The original PCMCIA cards are pretty rare and although you can use a CF card in a PCMCIA adapter you'll also need to find an image of a formatted card somewhere online, or you'll need to have an old PC / Mac with the correct SCSI connector. On the plus side, the official software is still possible to download.
Sony SAL 50mm f/1.4 | RD-175 Exporter
Competition
Nikon launched their reduction optics cameras, the E2/E2S in collaboration with Fujifilm, who called their models the DS-505/DS515. This was a 1.3 megapixel 2/3" sensor that shared the f/6.7 minimum aperture limitation, but had two ISO values to choose from (880 & 1600), a higher 1fps burst, and could capture the entire full frame 35mm field of view. Nikon also launched their base, E2 camera for $10,000 and thus was a more enticing option for pros than the Minolta. A 50mm f/1.4 would be equivalent to a 50mm f/6.7 here.
The Kodak DCS 420 came out a year before the Minolta (1994), at a slightly higher price ($12,000). Its resolution was similar (1.2 megapixels) and it used a much more traditional sensor type, even if it was a rather small one. The Kodak's 2.6x crop was rather awkward, but at least you could use your lenses real minimum aperture. This made a 50mm f/1.4 lens an equivalent 130mm f/3.64. Yeah, OK, that's not great, but it was a lot better than it becoming a 100mm f/13.4 on the Minolta! The Kodak's colours were magenta tinted due to a weak internal IR filter, but Kodak still had the objectively better option at the time.
Final Thoughts
Being only four years into the digital SLR story, cameras like the RD-175 are a fascinating piece of the digital camera history. It may not be a pretty camera, or comfortable to use, but it feels pretty amazing to be able to shoot with it after all this time. The window into the past it offers is amazing and the way it contextualizes modern technology is something special. I think everyone should experience this every now and again, to be reminded of how far the technology has come and how amazing modern cameras are. Part of Konica Minolta's engineering expertise led to the development of models like the Sony A1 mkII, so I am glad that their innovation continued, despite this risky technological experiment.
Apart from formatting the memory card, getting this camera working was surprisingly not too painful. The battery experience was totally fine, which surprised me after the painful Kodak experience on newer cameras. Getting the softwar
To all intents and purposes, these images are upscaled from 0.38 megapixels. Technically, the red and blue channels are only half that (190,000 pixels each). This, combined with the effective minimum aperture of f/13.4, and it's a miracle that the images can look as good as they do.
Resources
Here are some useful links if you own (or are thinking about owning) a Minolta RD-175:
-
256MB Card Image: Direct link + My OneDrive
More retro digital Minolta Reviews by Ralf Jannke:
Sony SAL 50mm f/1.4 | PicaJet
Bonus Squirrels
If you know me, you'll know I always have some squirrel photos in my camera reviews. I wasn't going to do it for the Minolta because I knew there is very little subject isolation and the camera wouldn't handle low light very well, but I decided to take it out on a very sunny day and was lucky enough to capture some kits being taught how to squirrel in the park.
Sony SAL 50mm f/1.4 | RD-175 Exporter
