Newbie with some theoretical questions on... camera modding..

[Cartogrophotographer]

For quite some time now, I have pondered the possibilities of people with the right know-how making changes to their cameras. Almost like how the fictive character of Tuco (in The Good, the Bad and the Ugly) assembles a good gun by scavenging parts from other guns, has anyone you know of attempted something similar? I mean is it even feasible given good equipment and knowledge? For example: what would happen if you would put a Lumia 1020 sensor in a Powershot SX50, or in a similar Camera? Would that not produce (given that the lenses worked with the new sensor) a superzoom with insane resolution and something that would be very cheap in comparison to what it could do.

This brings me to my second point:
Sx50hs is a bridge-camera with 50X zoom. (24-1200mm 35mm Equivalent).
Such zooms does not exist for DSLRs and those telezooms who do exist are highly expensive. Now I imagine that these are of higher quality than the one on the SX50, bu what I wonder is why they do not produce similar and removable/interchangeable superzoom lenses for the DSLRs?

Anyone?
Yes i'm a newbie.

 

[Gavjenks]

Making your own digital camera is not very feasible. You can't just swap sensors around. They have different numbers of rows and pixels and the ribbons wouldn't physically line up, etc. They may also have different bayer arrays and data formats and voltage thresholds, etc., so even if you did physically hook them, up, one or both sides of the circuit would probably just fry.

Making your own film camera is really easy and can literally be as simple as a cardboard shoebox with a hole in it and a piece of tape. Up to as complex as you want with a full field camera with all technical movements and a rangefinder and viewfinder, etc.



As for the second part of your question, the reason why bridge cameras have superzooms is NOT because the camera companies are cheating you. It's because they have tiny sensors and they don't have mirrors.
1) Tiny sensor = the ability to use physically small pieces of glass, that only project a very small image. If you put this lens in front of a larger sensor, you would just get a tiny portion of the sensor being used, and all the rest would record a dark black circle of nothingness.
2) No mirrors means the lens can be closer to the sensor, which decreases the complexity of the lens design, requiring fewer pieces of glass, etc. and making it affordable to make larger zoom ranges without horrible quality. This can be done with larger sensors, and it would similarly allow a wider zoom range. However, currently, you lose high quality autofocus ability when you do this, because the mirror system allows light to be diverted to the bottom of the camera body where there are dedicated autofocus sensors. Remove the mirror, and autofocus has to be done on the image sensor instead, which is currently not as well performing.


So all in all, if you tore off a superzoom lens from a bridge camera and stuck it on a DSLR full frame body, you would:
A) just get images that are almost all black, and waste most of your resolution (the result being even crappier and lower res than the bridge camera sensor) and
B) you wouldn't be able to focus any further than maybe 6 inches in front of your lens, assuming you could even focus AT ALL, because the lens couldn't get close enough to the sensor to focus as designed, due to a mirror being in the way.

 

[KmH]

As far as swapping image sensors, there are a lot of support electronics and software that would have to be considered.
Like the camera's image processor computer.
The 2 image sensors you refer to are not even the same size, but both are about as small as image sensors get.

The Sx50hs zoom lens has an actual focal length zoom range of 4.3 mm to 215 mm.
Because the image sensor in the Sx50hs is as small as they come, it has a crop factor of 5.6x which affects the apparent Field-Of-View.

Small image sensors and large crop factors limit how shallow depth-of-field can get.

 

[Big Mike]

Welcome to the forum.

The biggest difference between a DSLR and most other digital cameras (compacts, super-zooms, bridge etc) is the size of the sensor.
A typical DSLR has an APS-C sized sensor. (Sensor sizes range from 20.7×13.8 mm to 28.7×19.1 mm). Some DSLR cameras (full frame) have a sensor that is the size of 35mm film (36mm x 24mm). So when designing and making a lens that can project an image circle big enough to cover those sensors, there are obviously some size and cost contraints.

Now if you look at the sensor size of 'all those other' cameras....they are much smaller. I just grabed the first example I could find... 1/1.7" (7.44 x 5.58 mm).
So when your sensor is so small, it's easier and cheaper to design & make a super zoom lens.

That being said, there are 'super zoom' lenses for DSLR cameras. 18-270mm for example. The problem is that they have to compromise the image quality in order to make those lenses small enough, light enough and affordable enough for their target consumer (which is probably a 'soccer mom' who doesn't care all that much about image quality).

 

[Cartogrophotographer]

Thank you for your replies everyone!
Feels better to at least grasp the basic of it, the thoughts was really eating at me for quite some time.
So I guess the the 42 Mp Lumia sensor is too big, but that it theoretically(?) could be done with bigger lenses (which would increase cost), but at the same time, the price of this theoretical camera would drop to more commercial levels IF customers was OK with manual focus (But wait! bridge cameras, like SX50 does have auto-focus without a mirror, right so...)?

 

[amolitor]

You could probably swap the sensor+electronics in one go into something else, in some cases.

Arguably this is exactly the same as chopping the lens mount off whatever you started with and gluing on a different mount, though. The stuff in the middle is just a box.

 

[Gavjenks]

IF customers was OK with manual focus

No no, it's not that autofocus doesn't work at all. It's that autofocus is significantly slower and less accurate than SLRs currently. Though the 70D that just came out has some new technology on that front. From what I've read, it's still not as good as SLR mirror-down autofocus, but it's a lot closer than before.

Tons of cameras have SOME (not so fantastic) autofocus via their sensors alone.

You could probably swap the sensor+electronics in one go into something else, in some cases.

Arguably this is exactly the same as chopping the lens mount off whatever you started with and gluing on a different mount, though. The stuff in the middle is just a box.

Yes chopping the lens off and somehow jury rigging an EOS or F mount or whatever on there instead might actually work and be somewhat doable. Nothing else is going to work, though. Electronics are attached to the back screen and every single button, and you have to replace all those, resolder them, make or repurpose new button and screen holes, without a single light leak anywhere...

And if it's a DSLR, you have to reinstall everything within probably a couple of thous of tolerances (if the AF sensors are any different distance from the mirror as the image sensor, you'll get front or back focus)




But seriously, @OP, do you just want to know more about how cameras work? Or do you actually want to build a camera? If the latter, you should look into film cameras. You can make some really awesome ones by hand if you are decent at carpentry and back yard engineering.

 

[Derrel]

I thought for sure the OP would get a lesson in how to prototype his own cobbled together camera...

Wow, this thread was a shocker and a disappointment to me...

 

[Gavjenks]

I would love to give all sorts of cobbling ideas, but he seems fixated on the nigh-impossible task of cobbling digital.

 

[Cartogrophotographer]

>Gavjenks

Well, I have several reasons to ask the the questions I did. I did want to know more about this aspect of camera functionality. And I do have plans to try to make my own film camera, eventually. But I guess my immediate concerns were about the following:

Why is it that no powershots (or similar) has been made (from manufacturers) with a sensor capable of very high resolutions? (for example with the 41MP in a compact/bridge superzoom. I imagine it would do wonders for capturing details when documenting the smuggler boats far out at sea).

Why is it that there is not an busy industry of people buying and turning in parts to workshops- or classes in how to assemble them into camera equivalents of Frankensteins monster (for example a SX50 with a 41MP sensor from a Lumia) or some other custom made configuration?

 

[Gavjenks]

Why is it that no powershots (or similar) has been made (from manufacturers) with a sensor capable of very high resolutions? (for example with the 41MP in a superzoom I imagine it would do wonders for capturing details when documenting the smuggler boats far out at sea).

A = A full frame lens made for a full frame 35mm sensor. Let's say this is a 40mm lens, whatever. The yellow lines are the two most extreme points that will show up on the sensor, and the black lines indicate its field of view.
B = A lens of the exact same curvature (40mm), designed for a small sensor. Note that it is massively smaller. Could easily weigh like, 1/10th as much. But the outsides are curved the same amount. Since it is smaller though, the most extreme objects that can be seen are not as extreme. So it's field of view is narrower (by the crop factor). Objects as far out as in A would fall outside the sensor and not be registered.
C = a lens made for a small sensor placed in front of a large sensor. it can still only capture objects in the NARROW range. Thus, it only projects an image on a tiny circle in the middle of the sensor. The other 90% of the sensor or whatever would just be black.

So why are there no 41 MP superzooms? Well:

1) Superzooms are only possible to make for small sensors. Why? Because look how much smaller that piece of glass is. You're gonna need like 18-25 or so of those pieces of glass to make a decent superzoom, and it's only reasonable with the small pieces of glass. If you had 18-25 of the larger pieces of glass, your lens would weigh a good 70 pounds and cost as much as a house.
2) Lenses are only capable of achieving some maximum amount of resolution. They can't distinguish detail at infinitely small scales. A lens might have, let's say for example, 120 line pairs / mm of maximum resolution, before the glass just isn't perfect enough anymore. Well, if your sensor is 35mm wide, then that means you can have about 8400 pixels across before the pixels stop being useful. But if your sensor is only 10mm across, then you can only have 2400 pixels before more pixels stop being useful, because a millimeter is a millimeter is a millimeter and the glass has the same limits in both cases.

So for a 35mm x 24mm sensor (full frame) in this example, the maximum pixel count that the lens could resolve at = 48 megapixels.
But for the 10mm x 7.5mm sensor (something similar to a small point and shoot or whatever), the maximum pixel count that the lens can optically resolve at = maybe 4 megapixels.

if you have more pixels than your lens can resolve, the pixels are useless. A single maximally small detail from the lens will just smear across multiple pixels without achieving any meaningful extra resolution.

So you have to CHOOSE:
Lots of megapixels that can actually DO anything, OR
A superzoom that is possible because it doesn't weigh 70 pounds.

Why is it that there is not an busy industry of people buying turning in parts to workshops- or classes in how to assemble them into camera equivalents of Frankensteins monster (for example a SX50 with a 41MP sensor from a Lumia) or some other custom made configuration?

Because DSLRs look like this inside:



You're gonna need a helluva lot more than a "workshop" to do anything with that other than turn it into an interesting paperweight.

And because doing things like putting a 41MP sensor behind a massive superzoom designed for an 8MP sensor will not work, for optical reasons described in part 1 of this post. All it will do is give you photos that are 90% black with a tiny little image in the middle that is BEST CASE the same as having taken it with the original camera, and WORST CASE even lower resolution and crappier than the original camera (because larger sensors usually don't just add pixels. They have larger pixels as well by some amount, so the number of pixels in the projected image area may actually be lower than in the tinier superzoom camera)

Your magnificent 40 megapixel frankencamera might produce images something like this:

 

[Light Guru]

I would love to give all sorts of cobbling ideas, but he seems fixated on the nigh-impossible task of cobbling digital.

That's saying a lot. If there is anything I have learned about Gav is that he likes to tinker and will continue to try and find a way to make something work even if the idea sounds completely ridiculous to other people (like melting the edges of sheet film together to create a long peace of large film instead of using tape or actually getting large roll of uncut film for a 4x5 roll film camera.)

I love Gav's passion and unwillingness to give up. So if he says its nigh impossible then that is saying something.

 

[Cartogrophotographer]

>Gavjenks

Thank you so much for your thorough breakdown of the issues at hand. I really appreciate it.
So I guess we will have to wait for technological advances in sensor light sensitivity and sensor resolution before we can expect a significant jump in MPs. I guess it is also a question of how clear you can make the lenses without significant increases in cost. (Still Parasonic DMC-FZ70 supposedly have has 16.1 MP @ 60X.)

 

[Gavjenks]

>Gavjenks

Thank you so much for your thorough breakdown of the issues at hand. I really appreciate it.
So I guess we will have to wait for technological advances in sensor light sensitivity and sensor resolution before we can expect a significant jump in MPs. I guess it is also a question of how clear you can make the lenses without significant increases in cost. (Still Parasonic DMC-FZ70 supposedly have has 16.1 MP @ 60X.)

There are theoretical physical limits to how well a lens can resolve. Glass can only be so smooth at the molecular level, etc. Also, even if you could make a perfect lens, the effect of diffraction will limit you instead.

For f/4, for instance, the maximum theoretical resolution is something like 400 distinguishable line pairs per millimeter. Which is about 1000 pixels or so.

If you were to apply this to the sort of tiny sensor required to make superzooms, this would give you maybe 50ish useful megapixels?



That's the optical maximum that's like, physically possible, mind you, probably in a PRIME lens, with a rock solid tripod or similar and maximum technological advances. Not the same thing as a realistic resolution in a superzoom lens actually for sale with dozens of elements in it, etc.

 

[bratkinson]

I strongly doubt the ability to make much of any changes inside a camera of any design.

Back in 'the good old days', a friend and I put an Oldsmobile J2 rocket engine into a 58 Ford, as I recall. Fortunately, his dad had a welding shop and fabricated new motor mounts and transmission mounts as the tranny was an inch or so further to the rear. Car customizers then and now have to fabricate numerous parts 'just to get it to fit'.

I used to build computers in the earlier days of PCs. Due to the numerous computer manufacturers that sprang up out of nowhere, other than RLL and MFM hard drives, little else was interchangeable...not even the BOX! It was only the 'standardization' forced by needed LOTUS 1-2-3 hardware compatibility that caused manufacturers to -somewhat- standardize. Everything from motherboard screw hole locations to motherboard socket design and locations as well as power supply designs, pinouts, etc. But today, store-bought computers are largely non-interchangeable parts...save RAM (if you know which speed and size limits) hard drives of like kind (IDE, SCSI 1, SCSI 2), and added video cards. etc.

But cameras? While I have never 'opened up' a digital camera, from pictures I've seen, in my mind, there is no interchangeability possible. As mentioned above, sizes, shapes, plug connectors and related 'which pin goes where' are ALL different from vendor to vendor, and, I dare say, even for model to model by a single vendor. I even doubt one could transplant anything from a Canon 5D2 to 5D3.

Then you get down to the computer inside...different processors, different proprietary on-chip microcode, user updatable firmware, internal RAM, faster buffers....all different.

I guess I have to ask...what would be the possible advantage gained in 'hack building' a camera? It's not like personal computers that hard drives and a myriad of other brand-new designed-to-fit components are ready to go. Considering the electrical engineering, mechanical engineering, and even some good old 'Rube Goldberg' engineering required to achieve even a simple 'sensor transplant', for example, the effort needed far exceeds 'reasonable and prudent' in my estimation.