# An idea of telephoto lens for wildlife picture shooting



## szkorotko (Dec 22, 2017)

Hi, it might not be the best place to post this thread so please be lenient 

I have an idea of telephoto adapter for smartphones. Everyone carries a smartphone in a pocket so why not use it for wildlife photography? The only missing piece is a reasonably narrow FOV, which will give large magnification. So I came up with an idea of developing one because I couldn't find any good quality telephoto adapter on the market. There are many telephoto adapters, but actually, all of them are rubbish.

The idea itself is very simple, I just designed the optical system based on the telescope design (quite fast F/5 telescope). You can compare my solution to a mirror lens, below are renders of the design:

















The main pros of this solution are:
- small size and weight
- very good image quality (this is Schmidt-Cassegrain telescope)
- easy and repetitive mounting solution (not visible)

The whole setup you can mount on the tripod (still I am thinking how to solve it) and shoot wildlife from a decent distance. As you can see on the renders the picture shooting is very ergonomic, because the telephoto adapter is mounted sideways. This means that when you are taking pictures of an object in front of you, then you do not have to put a smartphone in front of your eyes just to see what is on the display (I hope you can visualize this  ).

What do you think about such solution? Would that be a good idea to proceed with a prototype? What do you think is important in wildlife photography from equipment perspective? Any answers would be much appreciated.

Best regards,
Simon


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## goooner (Dec 22, 2017)

Do you have any sample fotos taken with your lens?


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## szkorotko (Dec 22, 2017)

Well, no because it is still not manufactured. I need to know if there is a potential market for such solutions  But I have some renders from optical software, where I have designed the optical system. You can check the renders here: Magnifico.tech on Twitter (the second one is an image simulation showing image quality of available adapters on the market).


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## jaomul (Dec 22, 2017)

Will it focus fast enough to be useful.


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## szkorotko (Dec 22, 2017)

The focus is on this adapter manual, which means that you need to rely mostly on your skills.


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## FotosbyMike (Dec 22, 2017)

Will Smart Phone cameras focus close enough to be able to focus on the mirror inside the lens? Then trying to hand hold this at the focal length is going to be tough. 

Cool idea, nice CAD work but not sure it's for me.


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## szkorotko (Dec 22, 2017)

No, it is not possible to focus on the inside mirrors  From simulations it seems that the closest focusing plane would be about 5-6 meters away from the lens.


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## 480sparky (Dec 22, 2017)

FotosbyMike said:


> Will Smart Phone cameras focus close enough to be able to focus on the mirror inside the lens? ..............



You don't focus on the mirror.  You focus on the subject.


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## KmH (Dec 22, 2017)

f/5 is quite fast for a catadioptric lens, and being that fast the lens won't give as much magnification as a slower (longer focal length) lens.
The field curvature at a focal ratio of _f_/5 will be quite noticeable.
Meade and Celestron Schmidt-Cassegrain telescopes have a _system focal ratio of f/10_ that results from using an _f_/2 primary mirror and an _f_/20 corrector mirror.
The corrector plate and the secondary mirror for a Schmidt-Cassegrain are some what complicated to make.

The greater the 'reach' the steadier the mobile device would have to be mounted.

Simpler, and cheaper to make is the Maksutov negative meniscus lens corrector used for a Maksutov-Cassegrain. At _f_/5 chromatic aberration may be an issue.
Schematic image of Maksutov-Cassegrain. Use license: CC BY-SA 3.0 Author: Halfblue at the English language Wikipedia


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## szkorotko (Dec 22, 2017)

KmH said:


> f/5 is quite fast for a catadioptric lens, and being that fast the lens won't give as much magnification as a slower (longer focal length) lens.
> The field curvature at a focal ratio of _f_/5 will be quite noticeable.



Yes, that is true, but we do not want to compromise on image quality and size. This is our first priority, it must be high quality and compact. Modern smartphones cameras have very large resolution sensors (usually 12 MPx). It will drive the cost up, but with large volume production, there are manufacturing technologies that can reduce this cost significantly.

Here you can see my telephoto adapter system layout:





Actually, the biggest challenge was to design reasonably small  "eyepiece"  which will project an image from the telescope into wide FOV smartphone camera lens


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## FotosbyMike (Dec 22, 2017)

480sparky said:


> You don't focus on the mirror. You focus on the subject.



How is the smart phone camera going to focus first, then the lenses will focus on the subject.


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## tirediron (Dec 22, 2017)

Moved to an appropriate forum.


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## 480sparky (Dec 22, 2017)

FotosbyMike said:


> 480sparky said:
> 
> 
> > You don't focus on the mirror. You focus on the subject.
> ...



The image is not on the mirror.  There's nothing on the mirror to focus on.  The AF will focus on the subject, the same as if the mirror wasn't part of the optical path.


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## waday (Dec 22, 2017)

szkorotko said:


> Well, no because it is still not manufactured. I need to know if there is a potential market for such solutions  But I have some renders from optical software, where I have designed the optical system. You can check the renders here: Magnifico.tech on Twitter (the second one is an image simulation showing image quality of available adapters on the market).


I looked at your Tweet. Aren't they BOTH image simulations?

Also, shouldn't you try image simulations of the same subject? You're using two different images to compare to one another, which doesn't give an accurate depiction of image quality between your hypothetical lens to actual manufactured lenses.

What are you expecting costs to be?


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## szkorotko (Dec 22, 2017)

waday said:


> I looked at your Tweet. Aren't they BOTH image simulations?


Yes, they are both simulations, I did such comparison simulations earlier. Hopefully, our real design will be close to simulations:





and this is what you can get from telephotos available on the market:





Actually, you can search for the image quality of this kind of telephoto adapters on YouTube. Here you can find real  > example <

I am still not sure about the pricing since I don't have yet detailed costs estimation for volume production. I expect that optical and mechanical components will cost total roughly 60-90 USD.


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## waday (Dec 22, 2017)

szkorotko said:


> Hopefully, our real design will be close to simulations


If you can get that kind of quality from an iPhone lens, at a good distance away, that'd be spectacular. Good luck.

60-90 USD, that's for parts only, correct? What kind of markup would you expect from here?

The reason I ask is that, while I consider my phone to be a good general use camera, I hesitate spending any considerable money on lenses for it. I'd rather spend that money on my camera.

That said, I might not be your target market. Before I'd be willing to consider such a lens, I'd need to see real results. When do you anticipate creating a prototype?


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## szkorotko (Dec 22, 2017)

iPhone cameras are actually very good, people do not often realize that these small lenses are producing high resolution images, the optics itself is really remarkable. What is limiting these cameras is the sensor itself, because the pixels are getting smaller and smaller. So in order to utilize this resolution, the telephoto addon itself must be high quality as well (i.e. optics, assembly, etc).



waday said:


> 60-90 USD, that's for parts only, correct? What kind of markup would you expect from here?


Correct, so there is still an unknown cost of the assembly, testing, logistics etc.



waday said:


> That said, I might not be your target market. Before I'd be willing to consider such a lens, I'd need to see real results. When do you anticipate creating a prototype?


Currently, I am waiting for delivery of the mechanical parts. The optics is already testes and looks promising (it means it is manufactured according to the documentation). I am expecting to assemble and test the prototype units in January 2018, and if everything will go as planned (successful crowdfunding campaign), then we are expecting to launch the product to the market at the fourth quarter of 2018. So as you can see there is many ifs and unknows


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## waday (Dec 22, 2017)

szkorotko said:


> I am expecting to assemble and test the prototype units in January 2018


Be sure to keep us updated on your prototype and sample images!


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## Donde (Dec 22, 2017)

Gosh I thought it was an alien drone at first.


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## szkorotko (Dec 28, 2017)

Some ppl at an early stage of the project were thinking that it looks like a yellow submarine attached to the smartphone, so alien drone doesn't sound that bad after all


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## KmH (Dec 28, 2017)

Tiny image sensors and tiny pixels are the biggest problem with mobile device cameras, even the cameras in iPhones.
The iPhone 5 has a 1/3.2" image sensor while the iPhone 6 sensor is 1/3", both having a crop factor between 7x & 8x. 
Pixel pitch, the distance between the center of two pixels on an image sensor, for mobile device image sensors is usually somewhere in the 1.75 to less than 1.0 micron.

Does sensor size matter? YES! | Expert photography blogs, tip, techniques, camera reviews - Adorama Learning Center


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## szkorotko (Dec 28, 2017)

True, mobile cameras with a small sensor will never be as good as cameras using larger sensors, still at daylight conditions you can get pretty good pictures. For astrophotography shooting with longer exposition can reduce the noise to the level where they are no longer a problem.


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## vin88 (Feb 4, 2018)

szkorotko said:


> Hi, it might not be the best place to post this thread so please be lenient
> 
> I have an idea of telephoto adapter for smartphones. Everyone carries a smartphone in a pocket so why not use it for wildlife photography? The only missing piece is a reasonably narrow FOV, which will give large magnification. So I came up with an idea of developing one because I couldn't find any good quality telephoto adapter on the market. There are many telephoto adapters, but actually, all of them are rubbish.
> 
> ...


Simon;   good idea,  has been used.  holding or tapeing a lens or loope for close ups.  a snap on fixture for various lenses would be good where high quality is not required.


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## Lonnie1212 (Dec 21, 2019)

If a man can make a living from developing new technology why not.


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