My First "Mosaic" Digital Medium Format Image
Also worth considering is the price of lenses. The larger the sensor, the larger the lens needs to be. Tiny sensors only need tiny lenses (think cellphones). A sensor the size of a playing card requires a big lens and the larger the lens, the higher the price, generally speaking (quality is a huge factor in price too).
Each time a photographer moves to a larger sized sensor, the price of equipment jumps significantly. The same has always held true for film too. The smaller format of 110 film (same size as 4/3 inch sensors) costs less than the larger 35mm film (same size as full-frame sensors) which costs less than the even larger 120 film (same size as 645 medium format sensors) which costs less than sheet film like 4x5 large format film which costs less than 8x10 large format sheet film, etc. Film sizes go even larger and the prices go up exponentially for all associated equipment for a format. The same holds true for digital photography so photographers tend to stay in the 4/3 to full-frame range of sensors. 4/3 gear if you prefer smaller, lighter gear and full-frame if you prefer to prioritize image quality.
Over the decades, I've shot film in many different formats... some small, some large. I've also shot with many different digital cameras ranging from compact cameras with smaller 2/3 inch sensors up to cameras with full frame sensors. The smaller sensors do fine in some circumstances but you are still limited even in those rather confined 'perfect set of circumstances'. You have more and more latitude as the sensor size increases so, naturally, photographers tend to go as large as their budget will allow.
By saying you have more and more "latitude" with larger sensors, the latitude I'm talking about is in low light sensitivity including sharpness and color sensitivity in those low light situations. I'm talking about ultra-smooth tranisitions in tonal qualities that are impossible to capture in smaller formats. I'm talking about dynamic range. I talking about color depth. And, I'm talking about light gathering abilities. The larger the digital sensor (or even the size of the film), the more latitude you will have and this is very important.
Today, full frame sensors are in cameras that are quite small so they have become more prevalent among photographers. It used to be that a full-frame camera body alone cost more than $5000. Now you can get an even better full-frame camera body for less than $1000 on the used market. This was not true only 12-15 years ago though.
Just that short time ago, only the higher end wedding photographers seemed to have full frame cameras. Smaller sensors in the 2/3 inch to APS-C size were more common for most photographers back then. This was primarily due to cost but it was also because the cameras were very large back then and resolution was still relatively low compared to today. Back just that short time ago, digital photography technology was still on the tail end of the period I would call its infancy. In the past decade, cameras have become far smaller in most cases. Even though digital cameras have shrunken down in size across the board, the bigger the sensor or film, then the bigger the camera.
In the 1990s when I switched over to digital photography, I started with smaller 2/3 inch sensors and then to 4/3 inch sensors in the 2000's and then to APS-C and full-frame sensors by 2015. I've always wanted to try medium format digital photography though for all of the advantages that medium format provides. The major constraint has always been cost though. Even considering the fact that I only purchase low cost used photography gear, this medium format gear has always been beyond my budget. Another factor is size. I have significant spinal injuries so carrying around a medium format camera and lenses is not something I even want to do due to the physical pain it would cause. But... there is just something about medium format and larger formats that cannot be replicated accurately or easily using smaller formats. There is a tonal quality to the better medium format photography that cannot be replicated with smaller formats so, at some point, my goal is to find a decent medium format body at an affordable price on the used market. Actually, I've been keeping my eye on the path for at least ten years.
In the meantime, I continue to experiment with different ideas to replicate some of the features of medium format digital cameras and that is what I'm writing about here in this blog entry... replicating medium format as best as possible.
I recently found an adapter that allows me to use old medium format lenses on my Sony full-frame camera. As the title of this blog entry suggests, I create a "mosaic" by tiling my full-frame sensor inside a larger medium format lens to create a medium format sized image with some of the characteristics of medium format. So, I'm stitching together my sensor across the light that a larger medium format lens normally provides rather than what we do for a panorama by stitching together images. By stitching a mosaic of the sensor, we are replicating a medium format sensor. Better yet, since we're now shooting through a medium format lens, we are seeing that smoother fall off between in-focus areas and out-of-focus areas of the image (the better your full-frame sensor, the better this works).
The lenses used here are old second-hand 50+ year old lenses that are less expensive than newer lenses for smaller formats so that makes this a more affordable way to capture a medium format-type of image. Plus, after purchasing a couple of old medium format lenses to use with this adapter, I'll already have the lenses on hand if I ever do eventually find a low cost used medium format body (and I'm always searching). The prices of used gear drop more and more over time so, at some point, I'll likely pick up a used medium format camera body.
This adapter rotates the camera's sensor all around the inside area of the medium format lens capturing four images that are stitched together to make a 6x6 medium format image (see graphic directly above). The first image is horizontal... then I rotate the camera 90° to capture an image in the portrait orientation... then I rotate the camera 90° again to capture an upside down horizontal image... then I rotate the camera 90° again to capture the final portrait orientation image. When I stitch the four images in Photoshop, the resulting image from this enlarged mosaic of sensor area is 107 megapixels at 10,344 pixels x 10,344 pixels. Of key importance here is that the mosaic of sensor area covers what would be a medium format 6x6 area.
The photo of the model truck at the top of the page was the first image I captured using this adapter. The first thing I was struck by when I stitched this together was the sharpness.
The downside to this fabricated mosaic medium format technique is it is slow, big and clunky. It will only work with static objects like landscapes, still life, architecture, etc, and you must use a tripod. I suppose if you have a perfectly still model, then you could do a portrait but in today's world it is tough finding someone who would stay still long enough to use this technique. It is possible but would be less than ideal. I have difficulty finding any willing models so finding a model who is willing to be still like a model from 100 years ago is even more difficult.
This photo, at right, shows a medium format Pentax lens mounted on this rotating adapter. The adapter is mounted on my Sony full-frame camera. Note how much larger the adapter and medium format lens combo is when mounted on my full-frame camera.
Some photographers do something similar in panoramic photography. Panoramic photography renders noticeably different than shooting through a stationary medium format lens though. In this case, I'm shooting through an actual larger medium format lens with its own unique medium format characteristics and even its own flaws. The lens stays stationary while the sensor moves to fill the image circle created by medium format lens. In panoramic photography, the lens is a smaller format lens that moves with the camera requiring more attention to the nodal point. These stitched panoramic images, while providing more detail than normal single frame shooting, are missing the rendering that the medium format lens creates. So the difference is in panoramic photography a mosaic is created with the resulting photos after carefully aligning the nodal point at your point of rotation in all axes. Doing it the way I did here creates a mosaic of the sensor, moving the sensor around within the image circle that the larger medium format lens creates. The lens stays stationary and you rotate the camera for each image of the sensor mosaic.
For me, this is just another learning experience and photography project. I hope to capture a few landscapes using this new adapter and technique. I'll have to think of some things to capture in the winter though. Still life photography in the house will work for now but I also want to get outdoors to see how well this works and what I can create.
Below is another test shot from today. (After publishing this blog entry, I noticed that, on some devices, the cross-hatch pattern of the lampshade can show significant moire at certain reduced sizes (a diagonal rainbow over the cross-hatch). This is due to the incredible sharpness of the image. If you expand the photo to 100%, then the moire disappears.)
For these two initial images (the top photo and this lamp photo), I'm using an old Pentax 645 A 75mm f2.8 lens which is an all manual lens... manual focusing ring on lens, manual aperture ring on lens. This lens is known for its nice rendering as you can see in the rust detail on the truck at the top of the page and then the smooth fall-off of blur as the scene goes more and more out-of-focus in the background. What is unique and appealing about this lens is this out-of-focus blur... it is a uniquely smooth blur with a uniquely smooth transition in tonal quality. This characteristic is definitely visible in both of the images above. These are some of those unique medium format characteristics that photographers aim to capture and which are only found in larger formats. Part of this is due to the much larger sensor and part of this is due to the characteristics of these medium format lenses.
I should be able to capture some very interesting images this way and I'm looking forward to it.
Incidentally, I can use this same technique using my full-frame camera with large format 4x5 cameras and lenses too. I don't have a 4x5 film camera though. A 4x5 film camera is one of those big boxy, accordian-sided sheet film cameras with the blanket shrouded over the photographer's head. I have no desire to carry one of those around but capturing a few photos with one of those would also be incredible so I definitely would like to someday own one of these sheet film cameras too.
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After publishing this blog entry, I tried shooting this same scene as a panorama with a full-frame lens (75mm f1.8, so, the same focal length as used above) on my full-frame camera body rather than using the medium format lens as I did above. I tried it twice but, apparently, my nodal point was slightly off because Photoshop failed in both attempts to properly align the panoramic images. Then I attempted to align the images manually and I also failed at properly aligning the images. Everything was all wonky with curved perspective lines.
For close work such as this, that nodal point has to be set perfectly in order to make something like this work. I'm going to change my tripod head to a more suitable head in a third attempt to get this to work but this is a perfect example of how much easier it is to simply use this Vertex rotating adapter with medium format lenses.
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Okay... I swapped out the ball tripod head for a gimbal tripod head which is the right type of head to use for this type of image. I carefully aligned both axes to find the exact nodal point of the lens... I thought I had it set perfectly but stitching the images afterward didn't work. The images weren't as wonky as with the ball tripod head but they were still wonky enough that I couldn't perfectly stitch them together automatically nor manually.
Clearly, there is a huge advantage to the medium format adapter that I used to simply rotate the camera!
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I tried one more time with my gimbal tripod head (it bothers me when I can't get something to work that I feel should work)... no joy. My gimbal head is cheap so probably not as accurate as I need for this type of very close scene. Hmmm... or maybe the lens isn't ideal. Maybe I should try a different lens. Regardless of the next outcome, I am now seeing the glaring problems with my cheap gimbal tripod head.
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Well, I finally succeeded at shooting and stitching six images using my full-frame camera and different lens mounted on my gimbal tripod head. I had to shoot six images at 70mm focal length (using my Sony f4 70-200mm lens) to get the same field of view that I got with only four images using the rotating lens adapter shown above. That was extremely painful and the results are less-than-stellar. It definitely was not worth the extra work!
I actually had to resort to installing a different panoramic stitching program to accomplish this and I am not liking the result even though it did stitch together successfully. There are some odd artifacts in this new image. Really, I should reshoot this once again to perfect the image but, honestly, it is not worth the trouble. When I compare this new image to the image shot using the medium format lens, this new panoramic image is simply lacking. This is disappointing but it does show the strengths of the adapter and medium format lens I used for the first two photos.
I knew the medium format lens on this Vertex adapter would provide a nicer image (which is why I purchased it) but I didn't expect the difference to be so pronounced nor did I expect it to be so incredibly frustrating and difficult to shoot this scene without the adapter as a typical panorama when compared to using this rotating adapter. This Vertex adapter is great!
Here is the panoramic image using my Sony f4 70-200mm lens on my gimbal tripod head...
As a comparison, here is the medium format image again (it's easier to compare when the two photos are next to each other)...
Putting aside the fact that I definitely prefer the image captured through the medium format lens, the ease of use in capturing the necessary four images using this new adapter makes all the difference in the world. There was absolutely no fussing with the gimbal head nor fussing trying to find the nodal point perfectly. All I had to do was point it where I wanted it and shoot four images. This is definitely the way to go. Plus, I ended up with better images when using this very easy to use adapter!
This comparison also allowed me to get a better idea of the crop factor when using this Vertex rotating medium format adapter. Using this 75mm medium format lens that I used here with a full-frame camera provided a 40mm field of view in the standard full-frame equivalent. That means there is a crop factor of 0.54x. Part of this crop factor is due to the nature of using a larger sensor area but also worth noting is that part of this crop factor is due to changing the aspect ratio from 6x4.5 to 6x6 (ie, 4:3 to 1:1).
Personally, I have always liked the 4:3 ratio far more than the 3:2 ratio of most of today's cameras/sensors. The ratios closer to 1:1 (think photo prints at 8x10 or even 5x7) are much nicer. I find the 3:2 ratio to be too long on one side and too tight on the other unless I want something closer to a panoramic view. However, if I want a panoramic view, I'll lean toward wider ratios (ie, 2:1 or 3:1). The 3:2 ratio seems to be a very "uncomfortable" ratio that creates some tension for the viewer (well... this viewer).
Using medium format lenses on most of today's digital medium format camera bodies gives us a crop factor of 0.79x so this Vertex rotating adapter gives me a wider view with a crop factor of 0.54x. Medium format film (120 film), however, gives us a crop factor of 0.62x because the film plan is slightly larger than most medium format digital sensors. Now I can figure out what sort of view I will get with other medium format lenses.
Incidentally, today's Instax instant film provides medium format. Unfortunately, the lenses on most Instax cameras are rather poor and slow so the resulting Instax prints often look more like cheap prints from the 1970s. On the other hand, when I print my good digital images that I shot with good digital cameras, the resulting prints look great so I do this every now and then. I have the capability to print two sizes of Instax prints... 6x4.5 and 6x9 which is the larger end of medium format photography. When we head out for the night, I like to carry one of my Instax film printers (they are tiny) in case I want to print one of the photos I captured.
Anyway, this new Vertex medium format adapter is probably going to help me create some nice looking photos!
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