35mm lenses (What to buy?)

[Robert Paul]

Searching through these forums is quite the task these days, so I apologize if this question has been answered a million times in the middle of a 1000 post thread. I am building my own 35mm adapter for my GL2 and am having trouble deciding what lense to get. There are so many choices on ebay. Since this is my first adapter I want to stick with pretty darn cheap.

I also need a macro 58mm. Everyone says to get the Century Optics (?) one for a little over $200. I have been looking at the ones that come with wide angle adapters and fish eye lenses for the gl2 on ebay for $40-$80 and I was wondering if they would do the job.

After reading the orignal agus35 thread multiple times and then working my way up to the front page my eyes are definitley starting to burn... (oh look its morning) alas I have everything I need (motor and gg going and housing just about complete, I just need to decide on my lense and macro.

[Daves Spi]

The more time I have spent building 35mm adapters, Im getting feeling, that if you are going to use rotating CD, dont spend money on lens... I bought used Takumar 70-200mm for $40 and its perfect... Untill you will use perfect GroundGlass (and believe me, 800 is not good enought, it gives half resolution even if rotating). I found, that if I will use static focusing screen from Nikon for $10, I will get about 1/3 better resolution than with rotating GroundGlass from 800 grit glass. (I was shooting testing screen). I know the rotating things sound cool, but save your time and money if you mean it seriously... Look around for Beattie and change your way ;-)

[Bob Hart]

Can one get a better than 500 TV lines resolution from a 24mm x 18mm frame on the Beattie without static blemishes becoming visible when you pan and with no hotspot? Maybe it is possible.

If one is serious then one should aim for a finish equivalent or better than what the AO5 dressed surface yields and preferably move the groundglass by spinning, oscillation or whatever. There is not a lot of extra effort involved in spinning the disk on a CD spindle versus making up a suitable mount for a fixed screen.

If 800 grit is as far as it is intended to take it then the lens choice is fine.

My personal preference has been to aspire at least to the definition limits of MiniDV/DVCAM at about 530 TV lines and conform to the 35mm motion picture camera image size of 24mm x 18mm. I found I needed a groundglass of 5 micron finish, a good relay lens path and good SLR prime lenses to get there.

For MiniDV/DVCAM, standard imaging via an AGUS into a PD150, I have settled on :-

Nikon f1.8 primes, 28mm, 50mm, 85mm and a f2.8 135mm non-Nikon.

Relay path. Century Optics 58mm-mount 7+ Achromatic dioptre.

Groundglass of AO5 standard surface dressing. ( guilded the lily a little by making glass disks but practically as effective are the CD-R or DVD+/-R spacer disks which have been diverted from actual production and not injection molded. These disks are optically true and spin accurately.

I did not use condenser lenses but to get that last few percent in image quality they may well be needed. They are outside of my limited expertise.

I understand the GL2 may have the same filter mount and similar zoom lens spec.

[Leo Mandy]

Good luck on the path to 35mm greatness. So far Bob Hart and Agus are the only ones that I have seen that are amazing - the image and the quality. James Hurd has something in the works - check out his own thread for that. There is alot of time that need to be invested in this to get it right...

[Bob Hart]

Robert.

Have a look at "http://www.dvinfo.net/media/hart/grabmon4.JPG". I'm sorry this is not a link. I don't know how to do that href thing to liven the addresses into a link.

This is a montage of agus footage aquired in a low budget production environment under those sort of pressures with the items described in my previous post, albeit on a training project as part of a course. Except for mounting the grabs in a panel for the actors, no other manipulation of the images has occurred.

It was a two man crew, myself as camera op and director and a sound recordist/boom swinger.

Additionally, for the master shot on top, I had forgotten to turn the disk motor on so this is in effect a fixed groundglass shot complete with bits and pieces of dust, grit and fingermarks.

The colour is a bit flat. The conditions were, night, ambient light from one grubby overhead flourescent 40watt tube, equivalent of 300 watts incandescent from a small edison screw flouro in a photoflood lamp holder as the fill, equivalent of 150 watts incandescent from a small edison screw flouro in a photoflood holder as the key. One was positioned furthur from the subjects than the other so in effect they were cross keys.

There was no backlight. Though I would have liked one, conditions and resources did not permit.

With a bit of tweaking in post, the colours come up to an acceptable level.

PD150 shutter was fixed at 1/50 sec. all settings were selected manual. White balance was manually done for the lighting for the master shot and then not furthur tampered with.

As for sharpness of image, this sequence was shot through a prism version which is far from perfect and adds two more glass elements to the equation.

With ideal and precise construction and as much attention to perfection as some ALDU builders have been illustrating in their projects, AGUS footage in a practical shooting environment should be superior to this example.