50mm SHARP

[Loren Simons]

Will I ever find anything sharper than my 50mm f/1.4? I find my self using that and moving backwards for almost all my shots becuase of the sharpness. I have a 17mm f/3.5, and a 35mm f/3.5 and they are no where near as sharp! Is there another lens someone would suggest?

 

[Dli151]

yea, yo should be able to rock with the lens you have but i recently ran into, what you need to do is get more light, because i bet you have to keep your iris open with those slow lens, you need to close there iris and that will increase you dof, hence giving you a sharper image.

 

[Dennis Wood]

This is a loaded question as you need to determine if the issue is your lens, or your adapter! There are all kinds of issues that can affect sharpness...and here's just a few:

1. Your lens, imaging plane, and adapter must be aligned perpendicular to your camera with a tolerance ideally under .1mm. This is a tough challenge and in our case, only possible by CNC machining everything to much tighter tolerance to keep stack errors to the +- .03mm range.

2. Your lens collimation, in relation to your adapter, must be correct and done to a similar tolerance. Not knowing which adapter you're using, I could only point you to our video segment on the topic as a start.

3. Your adapter optics must take spherical and chromatic aberration into consideration to ensure contrast, MTF and the like are maintained at a high level. For us, the flip and Brevis MP.1 optics have been professionaly engineered with the above in mind.

We go to extreme lengths to make sure our adapter and optics are very high quality. That said, lenses are the number one issue to consider once all of the above is addressed. There are huge variations in contrast, sharpness, chromatic aberration, barrel distortion, edge to edge sharpness, fall-off etc. to consider in choosing a lens. The best way to choose one is to search for reviews and see what the still photographers are saying. We now stock Zeiss lenses specifically because we've tested them and found each to be outstanding in terms of all the issues I've mentioned. Additionally, they have a very high build quality, excellent manual controls and precise manual focus with excellent accuracy. So for new lenses, we haven't found anything better. That said, there are many, many great used lenses out there. The older Canon FD f2 35mm ,f1.4 50mm, f1.8 85mm and 135mm f2.8 are some of my favourite used lenses. The Nikon f2.8d series zoom lenses are also excellent. We've tested (and use) the 17-35mm f2.8d zoom, 35-70 f2.8d, and 80-200mm f2.8d. All are constant aperture and offer truly amazing performance for zoom lenses.

We do have a video segment on shooting with the Zeiss lenses at our Video University section, a session on collimation, and another coming this week on shooting with Canon's EF (EOS) lenses which you may find helpful in your search.

Cheers,
Dennis Wood

 

[Loren Simons]

Thanks, yeah i think lights are a main issue. I am using a redrock, and focus at .6ft on the gg. On my 50mm i couldnt ask for sharper, thus making me assume that its just a matter of lenses, I am contemplating getting a brevis or letus down the line though.

 

[Lenilenapi]

what are your lenses - Nikon's?
Are you using them wide open as opposed to using the 1.4 at 2 or 2.8?
It sounds likely to me like a lens quality issue.

 

[Beat Takeshi]

Sometimes the focus on the camera needs to be tweak as you change lenses. I learned that the hard way and all my wides were a little soft even though they look good in the monitor.

 

[Dennis Wood]

Good point. Focus with certain camera's like the EX1 can be a bit of a trick as the DOF relationship between the camera and adapter images is extremely tight. On wide angle lenses focus field curvature is hard to avoid, making focus tweaks like Aram is referring to, a good idea. Every video camera has the same issue to varying degrees. Lens testing with a good chart that is perfectly aligned to the camera is a great way to experiment.

On a completely unrelated note, one of our guys captured a spider (about 4mm across) using just our non-flip achromat on an HV30 yesterday. We'll post it up in a few days as not only is the DOF incredibly shallow but he was in so tight, you could see the compound elements of the little guy's eyes. I was completely bowled over with what they shot using an $800 camera and our "old" 72mm achromat. In this configuration the image is incredibly sharp, DOF is super shallow and all you've got on there is an achromat. You are of course limited by the focal length of the achromat but it's very cool if you've never tried it.

 

[armisiano]

Also your camera (be it DVX or HVX or FX1, HV20, whatever) will perform better (with an adapter) if it can be stopped down a tad bit as well. Example: I notice with my DVX/LEX setup that the GG is pretty sharp at 48, when I rack to 49 or 47 it goes a little soft (DVX iris wide open), that shows you how sensitive it is. If you have the ability (enough light) to stop it down a tad bit after getting it in focus, it'll only produce an even sharper image. Same with your SLR lenses be them Nikon, Cannon, or whatever.

Also (slight tangent here, pardon me) ask yourself HOW shallow you want all of your shot's DOF to be? Watch a good feature film, is EVERY shot SO darn soft? No. Closeup's yes, and occasionally for the sake of a very intentionally planned rack focus. But generally if you CAN stop things down a tad, do. The slightest added quality of noticeable depth that an adapter will lend you, with the occasionally pushed look of a good soft yet defined closeup, will benefit the "film-like" look of your footage plenty, there's no real need to keep everything wide open unless you have no choice. This second part of the post here is purely my opinion though.