Lens description for Letus Nikkor

[John L. Miller]

I do not mean to sound stupid, though I am when it comes to lenses, but if a lens is advertised as F1.8 Als, I know the 1.8 is to do with amount of light required, but what is the Als? When purchasing my Nikkor lenses, anything else in particular I should look for? J

[Steve Yager]

Originally Posted by John L. Miller

I do not mean to sound stupid, though I am when it comes to lenses, but if a lens is advertised as F1.8 Als, I know the 1.8 is to do with amount of light required, but what is the Als? When purchasing my Nikkor lenses, anything else in particular I should look for? J

Hi, John. 1.8 has nothing to do with the amount of light required. 1.8 refers to the widest f-stop on the lens. F-stops are the amount increments in which the iris opens up to let light in, and on this particular lens 1.8 is the widest.

AIS (Automatic Index - Shutter) Lens_
If there is a machined groove (Lens Type Signal Notch) in the base of the lens, you have an AIS, Series E, or Auto Focus (AF) lens. The purpose of the groove was to let the camera body know that aperture stop down was linear.Your camera can take advantage of AIS if it has a protruding pin on the camera lens mounting ring. If the pin is not on the camera body, it can't take advantage of the AIS feature, but the lens will operate as AI.

[John L. Miller]

Steve, you are the best. Thanks. J

[John L. Miller]

One more question then, is the 1.4 better than the 1.8?

[Rene Roslev]

Originally Posted by John L. Miller

One more question then, is the 1.4 better than the 1.8?

We would need to know which 2 lenses you are comparing.
Generally speaking, yes it is better - and propably costs four times as much. For same focal length primes (85mm f/1.4 vs 85mm f/1.8 for example) the 1.4 will most likely be sharper at same apertures and have more pleasing bokeh (rendering of out-of-focus). This added sharpness may not be visible due to the adapter ground glass, the XH-A1 stock lens and the resolving power of the XH-A1 sensor.
The larger aperture will be of little use with a 35mm adapter, the depth of field at 1.4 is so shallow it's virtually useless.
Unless you have a high-end Nikon DSLR and alot of money to spend I would say stick with the 1.8.

For lens reviews check:
http://www.fredmiranda.com/reviews/
http://www.photozone.de/8Reviews/

[John L. Miller]

What exactly is the NON-AI lense? thanks. J

[John L. Miller]

I figured out the AI and NON AI. I bought a 1.4 on the 50mm, so am I understanding correctly that this will not be a good lens for video? I got such a good deal I thought I had better buy it. I thought f1.4 would be better than 1.8 since it was better in low light. I didn't know that would make the depth of field that much more shallow. So I should get a 1.8 50mm? Thanks. J

[Steve Yager]

Originally Posted by John L. Miller

I figured out the AI and NON AI. I bought a 1.4 on the 50mm, so am I understanding correctly that this will not be a good lens for video? I got such a good deal I thought I had better buy it. I thought f1.4 would be better than 1.8 since it was better in low light. I didn't know that would make the depth of field that much more shallow. So I should get a 1.8 50mm? Thanks. J

Well, you don't have to always be at 1.4f. There will be a varying amount of f-stops to choose from. They just tell you what the widest one is. It'll likely be:
1.4
2
2.8
4
5.6
8
11
16
22

[Rene Roslev]

Originally Posted by John L. Miller

I figured out the AI and NON AI. I bought a 1.4 on the 50mm, so am I understanding correctly that this will not be a good lens for video? I got such a good deal I thought I had better buy it. I thought f1.4 would be better than 1.8 since it was better in low light. I didn't know that would make the depth of field that much more shallow. So I should get a 1.8 50mm? Thanks. J

It should be fine. Nikkor lenses usually have an aperture ring allowing you to stop down the lens.
The 1.4 is better in low light, but only at f/1.4 - at the cost of a very shallow depth of field. Once stopped down to f/1.8 it will let in the same amount of light as 1.8 at f/1.8 and have the same depth of field. It will however be sharper and most likely have slightly better color reproduction and more pleasing bokeh.

[John L. Miller]

Great! Thanks. J