Camera camera lens, push-pull scorch and anxious structure of change coming back, what actor drawbac

Hello, at present most scorch camera lens, it is anxious structure of adoption change coming back, conversely, the camera lens that uses push-pull scorch is less and less. Even, we are current can the most commonly used camera lens of bring into contact with, have one is push-pull scorch hardly.

Beautiful can scorch camera lens, great majority is change coming back anxious, this 28-300mm is very few adoption the scorch camera lens of push-pull scorch

About this problem, I am specific talk:

One, the result of the market, should have shown everything

If push-pull scorch is true this it may not be a bad idea that it may not be a bad idea, that why is the mainstream push-pull scorch?

2, inchoate scorch camera lens, basically be give priority to with push-pull

Especially 1980-1990 time, the scorch camera lens of which moment, be of scorch of too much push-pull really.

3, an advantage with anxious change coming back, it is camera lens length basically does not have what to change

Internal composition is more stable also, estimation is more durable also, fault rate is lower also.

But, defect, the likelihood is cost wants a bit a few more expensive.

Glue a short while is acting, scorch camera lens uses push-pull scorch means mostly

4, an advantage of push-pull scorch, design difficulty namely inferior, make relatively simple

But defect, it is scorch when, camera lens length can vary.

Additional, fault rate may be higher also.

With long, wear away the possibility is larger.

Of course, push-pull scorch has a the clearest advantage, this explodes in scorch namely when, the operation of push-pull means is more fast and simple, successful rate is higher also.