Questions for those who know.

[Dave Weber]

Can anyone tell me how the 18-50 measures up to an 18-50 35mm cinema lens. Is 18mm really 18mm and so on.

Also Does anyone know if there is enough room behind the lens for a net filter?

As always, any help is much appreciated.

[Jannard]

The lens is excellent optically and the mechanics have been described as somewhat less than typical cinema lens quality.

Soderbergh has used these lenses on "Guerrilla" and "The Informant". No complaints.

An 18mm is an 18mm.

Jim

[Shawn Booth]

BigLu - yes, you can net the lens if needed.

[Esteban Sosnitsky]

I guess your lens will "change" if you switch from 4K (full frame) to 2K where you will have a crop factor. Remember that red's chip is S35mm.

Still patiently waiting...

[Jannard]

I guess your lens will "change" if you switch from 4K (full frame) to 2K where you will have a crop factor. Remember that red's chip is S35mm.

Still patiently waiting...

You are correct. While 18mm is 18mm, that means something different to each sensor size.

Jim

[Michael Lindsay]

Hi

Has anyone successfully 'tweaked' the lens to hold focus through its focal length range?

regards

Michael

[chuck colburn]

Wait a minute I thought it was being used as a true zoom as opposed to a variable focale length lens.

[Jannard]

Wait a minute I thought it was being used as a true zoom as opposed to a variable focale length lens.

It does hold focus through the zoom range... because someone asks the wrong question doesn't make any answer true... :-)

Jim

[chuck colburn]

Aha, that's what I thought.

[Dave Weber]

Jim and Guys,

Thank you very much for the help. God I love this place!

[david_winters]

Weber,

Just shot a greenscreen job with your 18-50 and other days on the Ang 15-40. The only hassle we had was the compressed distance between focus marks on the Red lens. Focus marks were roughly 10', 12', 16' at about 30mm. The 15-40 has enough space between marks to consistently nail focus using the FF. On the 18-50 the marks were so close together that the gear play in the FF was enough to buzz some takes. Roll by sometime next week and take a look at the footage, in the final comps there is no way to tell which shot is from which day (lens).

[Tail Ends]

Jannard, I appreciate your candidness in describing the 18-50. Your comment match other posts. What bothers me is the silence on the 50-150's. Even you have not boasted on how great they are! Please give us your candid insight on this lens. I've been holding off on buying third party lenses, but from what I read about the 18-50 and silence on the 50-150, I'm about ready to punt lens-wise. Maybe the experience with the matt box will transfer to the lens project as well. I'm sure others than myself are looking forward to your answer.

Tail Ends

[Michael Lindsay]

It does hold focus through the zoom range... because someone asks the wrong question doesn't make any answer true... :-)

Jim

My local hire company put one up and it did not hold focus... Unfortunatly this trusted opinion and other unknown (to me) opinions on this forum led me to sumise that this was an issue.. I would be happy to buy the lens even if it shipped not holding foicus but could be tweaked to do so. I would not be happy if it was not possible to correct.

I'm sure it is still a valid question?

regards

Michael

PS If it is easy to fix and most lenses do no have this issue... I'm disappointed that I don't already have one..

[J. Eric Camp]

The lens not holding focus through it's zoom range would be a back focus issue not a lens issue. Your local hire should have known that. It takes only a few moments to adjust the back focus.

I have worked with both the 18-50 and the 50-150.

I will not say anything about the 18-50. It has known "characteristics." I will say that the 50-150 that I have worked with is better than the 18-50 in the most of the arenas where it fell short.

-eric-

[Michael Lindsay]

The lens not holding focus through it's zoom range would be a back focus issue not a lens issue. Your local hire should have known that. It takes only a few moments to adjust the back focus.


Hi Eric

I asked at the time if it could be simply shimmed to work and I was winced at and told that it was a bit of a mess (I was talking to the owner and not the tek)... On reflection I think I was wrong to not push deeper. I will ask the Tek Monday and try and hire one this week. Because I have seen so much negative feedback on the 18-50 I was (wrongly) taking a 'no smoke...' position.

I have on order the 50-150 and 18-85 to augment our Ultra-Primes but what would be really usefull is a short zoom..

regards

Michael Lindsay

PS Technical it is possible to produce a lens that does not hold focus AND can't be shimmed to work.. I do realise now that this is unlikely with a Red lens.