I need to say an important thing about the CA:

After the optical lab improve the grinding to get the best balance thickness between the sides of lenses the CA correction will be very better as shown in the day shots (day shoot lenses was good in thickness).

when I said in previous post that the CA could not be corrected when I lifted one side of that lens used in night shoots which shows difference in thickness, it is because it is caused by the angle formed by the inclination generated by the thickness difference. So lifting one side of the lens can help balance the corner sharpness because this aligns the curves between lenses, but it does not change the curves inside the same lens.

As I said I will try to get the best possible grinding from the optical lab to avoid the CA.

Thanks, stay tuned.

They have optical/electronic equipment to do measure lenses. I think what they need to do is a better alignment in the tools that hold and friction the lens in the machine which do the grinding. I will talk to them.

@apefos: Good thinking on the helicoids..!

I found the problem in the night shoots.

I used two prototypes, one for day and one for night. I did this to try a slightly difference in the lenses power, using the lenses I have from the first experiments.

The problem was not the difference in the power, I confirmed the problem was the difference in thickness as I said before. Comparing the lenses used in day and night I found the day prototype lenses was good with almost same thickness in both sides of the lenses, but one lens in the night prototype was with a 2,3mm difference in thickness from one side to other, I measured with a caliper rule. This increased the CA and softness in one side. As I said before, when I lifted this lens one side using some shim adhesive tape I got a better balance in sharpness between sides, but the CA could not be corrected.

So I confirmed the need for talk with the optical lab to ask them more precision when grinding the lenses. As I said before, probably I will need to deal with an error margin, but I will request them to do the best they can.

It is good to see another manufacturer recognizes my efforts and my accomplishments. Thanks.

About the coating, 250 usd will be enough to try the options.

OK guys, about the helicoid:

I decided to talk to my plastic machining partner one more time. I will beg them all the way I can. First thing I will say is:

"I do not want you to say things are difficult to do, I just want you to say how much you want to do it. I will allow you to destroy some pieces of plastic on your attempts. If you don't want, or if you can't, just point me to someone else."

Lets see what happens.

Thank you very much, I got the 25 usd. If I could get just more 9 donations like yours all the money problem would be solved to finish the project.

The reason the helicoids have different threads is:

smaller threads you need to do more rotations to move it some distance

bigger threads you need to do less rotations to move it same distance.

The camera lenses needs to be very fine precise focus, so they use small threads

As the anamorphic adapters needs to move font and back much more than camera lens to do the focus, the best option would be the 3mm

The problem for me is not to design it, the problem is to make it happen, to find some service that is willing to build it and do it in high quality. Also at this moment money is a big problem.

But I will consider it for sometime in future. Maybe one year from now, or less if I can raise enough funds.

Now it is impossible for me.

I don't know to answer this right now, it needs research.

But if I start to pursue the helicoid focus now, the project will fail. I would need to find another machining service or offer more money for my current partner. I would need to buy many pieces of metal, and metal is much more expensive than plastic, I would need to build some different systems to compare. Also metal would need another service after machining to turn it into black color and I do not know if this would change the behavior of the helicoid. So it would be "start from zero" again.

I think it is much more important now I try to deal with the optical lab to improve the lens grinding to get the best approach in same thickness. Also do my best to get the plastic body working the best as I can do. And also find the best coating.

If I can get a little more accurate thickness in lenses and the plastic body with a good alignment, this adapter will be a winner. It will work good at a good price range. This is what people call "best price/performance".

Between the "impossible perfect expensive product" and the "possible good enough affordable product" It will be better the possible.

About the donations, if someone agree with the non-refundable and non-discountable small donation just send me a PM or a post here and I will inform my paypal email. I prefer to inform my paypal email in the private message instead of here in the topic. Just do it if you feel good in helping and also consider the fact that the project can succeed or not.

@RRRR The idea of a helicoid focus is really great. And yes, I was thinking about it from some time ago. When I found the behavior of the lenses, the fact it need to move front and back I just picked up a Nikon lens in my hands and talked to myself: "If I just could build a thing like this..." But the problem is the plastic machining service started to say to me that this is so difficult do do, this will not work, this is too much for our resources..., they said the female thread would be difficult to do to fit perfectly in the male thread. So they did not manifest a willing to do. To be honest sometimes I think these people just want to avoid more complex job, they are always busy schedule so they can choose what they want to do. Due to this I simplified things to make it happen. But we need to wait a final word about the body design after it become ready.

I also have a good new information: I started to compare the grinded lenses I used since the beginning of the project and I found sometimes they show a difference in thickness between the both sides. So I will talk to the optical lab to ask them to do a more precise grindind to try to make them all the same thickness. I believe they can improve this, but as I know their machines and how they do the job, I will need to consider some amount of difference because probably they cannot guarantee the perfection, I believe they will guarantee some kind of a best approach.

I some new tests I found if the lens have a difference in thickness I can use some small pieces of black rubber adhesive tape in one side to calibrate and align the lens to the plastic pieces. It seems it helps to balance the corner sharpness but another problem shows up, the CA moves from one side to the other. I need to do more tests on this to say this for sure. If I can get more precise lenses it will be great, but if I need to consider an error margin, I believe it will be better to get better corner sharpness.

So after I talk to the partners and I build the bodies and lenses to try the coatings, I will find what will be the quality control I can offer, and what will be the error margin I need to consider.

Everything will be reported, no hidden things here.

I would only agree with non-refundable and non-discountable small donations from 10 to 25 usd to help me in the research and developing to finish the adapter (body and coating). I need to build three more bodies and pay for three different coatings to try them and finish the project. I will not get donations that can be deducted or discounted from the final price or refunded. The reason is: The adapter works good, I am sure about this, but there is a chance the final product do not meet all the expectations because I do not have the same resources the big manufacturers have, to offer the same precision they can do. You all need to consider it as "an improved DIY product" , not an "industrialized product".

I would donate with understanding that it might never get made, but that if it does I have option to get donation back as discount on purchase.

I'd also gift $20 just to see you succeed