Which Lens for my Bolex RX5?

[perthskydiver]

Hello all,

I'm having a small problem deciding which lens to use for my Bolex 16mm RX5. As its mostly for surfing shots from the beach, I need good telephoto lenses, therefore i've decided to use 35mm SLR lenses with a c-mount adaptor.

I was thinking either using a c-mount-pentax screw mount adaptor with 3 old primes in almost perfect condition, a Pentax super takumar 200mm f4, a 300mm Pentax super takumar f4 & another 90mm prime.

But a few people have suggested using a newer Pentax zoom lens instead. The new 70-300mm Sigma f4-5.6 APO was suggested & they've said since it a much newer lens with better coating & will perform as good if not better than the older prime lenses.

Anyone with any advice?

Thank you....

[super8man]

Stick with telephoto primes instead of zoom lenses. More elements, less light, more distortion.

I like the sounds of the 200 f4 lens. Good basic design on that optical combination. Won't let you down. Also consider like the 80-100 prime lens (Nikon has the 105 f2.5 or a 85 f1.8 for example).

Just say no to zooms and you will be better for it.

[perthskydiver]

I know prime lenses are usually better optically than zooms but do think so even when you compare older prime lenses to new zoom lenses|?

[ccortez]

(Nikon has the 105 f2.5 or a 85 f1.8 for example).

Yep, I've got that 105 f2.5 in my filmo bag now and I'm guessing that super8man is right on re: prime vs. zoom. I haven't shot anything with it yet tho, so I can't claim to know.

But I should do some tests when I get the chance -- I've got a couple of biggie Sigma zooms (and oldie and a newey, both about the same range) that I never use. It's finally stopped raining here in Texas, so tests are forthcoming...

I would love to join you in some surf filming. Too bad Perth is such a jaunt from here. I was in Puerto Escondido for my honeymoon last year, and the surf and surfers at Zacatela (sp?) were simply sick. Wish I had a 16mm rig with me at the time, but I don't think I was allowed filming as a priority. ;)

c.

[Nigel]

I have been building up my Nikon lens selection too. How well will these lenses work on a C-Mt?? My 200mm and 300mm (both Aaton Mt) are pretty heavy. I even use a lens support on them.

Good Luck

[ccortez]

I have been building up my Nikon lens selection too. How well will these lenses work on a C-Mt?? My 200mm and 300mm (both Aaton Mt) are pretty heavy. I even use a lens support on them.

Good Luck

The filmo is a tank and the Nikon C-Mt adapter seems well built, and even still I'm dubious with the bigger lenses. (I'm un-supported, sadly.) I'll let you know how it turns out later this week...

[Nigel]

You could have a serious tank but if it is shooting with a weak gun what use is it??

Meaning--The C-Mt. is a very weak mount and when you start to load it with big lenses that were made for a whole other type of shooting you may be asking for trouble.

Good Luck

[ccortez]

You could have a serious tank but if it is shooting with a weak gun what use is it??

Meaning--The C-Mt. is a very weak mount and when you start to load it with big lenses that were made for a whole other type of shooting you may be asking for trouble.

Well, a tank is known for armor not armaments. ;)

But I know what you mean and agree 100%. C-Mount is ass-y, and I doubt materials can even help much. Physics is the problem.

Time (and bent mounts) will tell...

c.

[perthskydiver]

mounting isn't a problem.. i have an adjustable lens support bracket which supports underneath the lens. i've sorted all the mounting & physical things...

what I want to know is the optical performance..

[Herb Montes]

Porter's Camera sells a universal lens support that attaches to the tripod screw on the bottom of the camera and will work with long and heavy lenses. I've seen it in their catalog and thought of getting one for my Bolex (I have a large Canon zoom I want to use on it). I don't know if it's on their website but you can search for it. The item number is 10-0791. Thier website is at:

http://www.porters.com

[perthskydiver]

or perhaps my question could be better answered on a Pentax users forum... anyone know a good Pentax message board?

[downix]

I happen to have that Sigma lens in my arsenal. Trust me, stick to the primes.

[Lunar07]

Hello all,
I'm having a small problem deciding which lens to use for my Bolex 16mm RX5. As its mostly for surfing shots from the beach, I need good telephoto lenses, therefore i've decided to use 35mm SLR lenses with a c-mount adaptor.
[...........]

This may be a false alarm - but are not these c-mount adapters made for the standard c-mount rear flange distance of 17.52mm? Would these adapters work on a Bolex H-16 Rex? Would you be able to focus with these slr primes?

[ccortez]

Hello all,
I'm having a small problem deciding which lens to use for my Bolex 16mm RX5. As its mostly for surfing shots from the beach, I need good telephoto lenses, therefore i've decided to use 35mm SLR lenses with a c-mount adaptor.
[...........]

This may be a false alarm - but are not these c-mount adapters made for the standard c-mount rear flange distance of 17.52mm? Would these adapters work on a Bolex H-16 Rex? Would you be able to focus with these slr primes?

It seems to me it would have to be an RX-type C-Mount adapter, if any such things exists. ???

[Lunar07]

Hello all,
I'm having a small problem deciding which lens to use for my Bolex 16mm RX5. As its mostly for surfing shots from the beach, I need good telephoto lenses, therefore i've decided to use 35mm SLR lenses with a c-mount adaptor.
[...........]

This may be a false alarm - but are not these c-mount adapters made for the standard c-mount rear flange distance of 17.52mm? Would these adapters work on a Bolex H-16 Rex? Would you be able to focus with these slr primes?

It seems to me it would have to be an RX-type C-Mount adapter, if any such things exists. ???

I really do not know. The RX type is peculiar to the Bolex system. A c-mount adapter to M42 or Pentax K or Nikon for example - does not have to be for the RX system. I am just not sure.