Calculating the focal length of 35mm lenses with super 8?

Post by **Mafishus** » Fri Jan 11, 2008 2:04 am

I want to use my 35mm and 50mm Nikon lenses with my Beaulieu 4008 II camera, but I'm not sure how to calculate the zoom factor. I may try to get some Super 8 of the Mavericks surf contest this weekend. The surfers are going to be almost a half a mile out. Anyone have a good formula?

Post by **super8man** » Fri Jan 11, 2008 5:27 am

You will need a longer lens...at least an 85 and better to use the 80-200 f2.8 or the newer 70-200 2.8...remember, you are only using the center sweet spot of the lens...have a massive tripod to calm down the shakes...

Post by **mattias** » Fri Jan 11, 2008 10:30 am

the focal length of the 35mm on super 8 is 35mm, and the length of the 50mm is 50mm. the calculation is quite simple actually. :-)

so, that was to answer your subject line, then you mention zoom/crop factor in your post and that's another story. the 24x36 frame is 36mm wide, the super 8 frame 6mm, so the crop factor is 6, hence you get the same field of view from the 50mm lens on super 8 as you would a 300 on your slr.

but let me stress this again: the focal length *does not change*.

half a mile is about 800m, so the width of the frame at that distance using the 0.05m lens is 0.006*800/0.05=96m=300 feet. sorry for the metric system but it makes calculations so much easier. i'm otherwise fluent in feet too. :-)

so, the 50mm will give you a rather perfect wide shot of it all, but as mentioned you'll probably need a 200 or so to actually see the surfing. the nikkor 200/4 is a great lens and it's cheap.

/matt

Post by **Nigel** » Fri Jan 11, 2008 6:10 pm

Just to correct S8Man.

The 70-200 AFS won't work on your Beaulieu since you can't adjust the f-Stops manually--Nikon controls the f-Stops via the body. You will need to stick to one of the 80-200's.

Good Luck

Post by **super8man** » Sat Jan 12, 2008 2:32 am

Thanks for that...I had just presumed that the top of the line lens (in the ratio) would allow for such things as simple as setting your own aperture.

But, I am wrong: "New G design enables apertures to be selected from select Nikon AF SLR camera bodies."

Compatible with the F5 but not the F3...interesting.

And yes, the less expensive Nikkor lenses like Mattias mentions are real gems for super 8 shooting...

Post by **Nigel** » Sat Jan 12, 2008 3:54 am

I know it kinda sucks N90 and higher should work with the ring free lenses.

I want the 70-200 but instead I will have to go with the 80-200.

Using that zoom is nice on 16. It isn't really long but the crispness is nice and it doesn't cost an arm and a leg. 1k for an AFS lens is a pretty good deal.

The only downside is that you don't have the long pull for racking focus like cine lenses.

Good Luck

Post by **S8 Booster** » Sat Jan 12, 2008 8:53 am

allthough this is for 8 & 16mm it may give you a picture - 16mm x 2 = 35mm (prox)

Post by **matt5791** » Wed Jan 16, 2008 3:23 pm

Nigel wrote:I know it kinda sucks N90 and higher should work with the ring free lenses.

I want the 70-200 but instead I will have to go with the 80-200.

Using that zoom is nice on 16. It isn't really long but the crispness is nice and it doesn't cost an arm and a leg. 1k for an AFS lens is a pretty good deal.

The only downside is that you don't have the long pull for racking focus like cine lenses.

Good Luck

How about the 80-200 AIS Nikkor - this ia a cracking lens and available for a LOT less than the f2.8 AF Nikkors - if you don't need the extra stop. Also being manual focus lens it is designed for.....manual focusing - which is what you want.

Matt

Post by **super8man** » Thu Jan 17, 2008 12:54 am

on 35mm prints, you would be able to notice the difference in pictures when shot with that lens vs the 80-200 f2.8ED...and the price point for the latter lens is very reasonable...everyone is getting rid of it in favour of the silent wave and the 70-200 digital varieties so they are real bargains. No point for the f4...also the brightness of the image will be dimmer...

Post by **Mafishus** » Thu Jan 17, 2008 1:21 am

I went the cheapest route, and purchased a Nikkor 80-200mm f 4 AI for $85.00. Unfortunately, I couldn't get my hands on it before the surf contest. I may get a chance to use it in the next couple of weeks, though. I'll post screenshots if that happens... Hopefully they won't be to dim

Post by **matt5791** » Thu Jan 17, 2008 8:04 am

super8man wrote:on 35mm prints, you would be able to notice the difference in pictures when shot with that lens vs the 80-200 f2.8ED...and the price point for the latter lens is very reasonable...everyone is getting rid of it in favour of the silent wave and the 70-200 digital varieties so they are real bargains. No point for the f4...also the brightness of the image will be dimmer...

The difference in quality between the f4 AIS and the f2.8 AIS ED is extremely minimal - the f4 is a very high quality lens indeed - yes the f2.8 is a better lens but you would require a very experienced eye indeed to spot one from the other in prints, and then only, possibly, under more challenging lighting conditions.

Also $85 for the f4 is a total bargain and totally disproportionate to the quality of this lens.

Are we talking about the same f2.8 though? The f2.8 AIS ED from the 1980's is very rare and expensive and weighs in at about 2KG. Or are we comparing with the later AF f2.8 varients, of which there are various models?

Either way, the f4 AIS is a superb performer - I have shot numerous weddings with it - what lets it down is speed, not quality.

Post by **fogo** » Thu Jan 17, 2008 11:29 am

My only worry here is that the 200 will prove to be too short at those kind of distances, especially if you want any kind of 'detail'....I'm experimenting with a 280mm lens for surf stuff...at these lengths, camera stability (and focus) become absolutely critical, as Super8man pointed out. Let us know how u get on, but if you can, try and beg borrow or steal something longer to do some side by side comparisons.

Ade

Post by **Mafishus** » Mon Mar 03, 2008 6:24 am

I posted surfing footage on my weblog that uses the Nikkor 80-200mm lens. www.framedin8.com

Post by **super8man** » Mon Mar 03, 2008 7:11 am

Nice work. I liked the Rhapsody in Blue better of the two surfing clips. The motion seemed a bit fast at times but perhaps that's 'cause I don't surf and it's a perfectly natural speed as shown.

I liked it though. Next time I am out that way, I'll let you know...There's an outrigger canoe race out there once a year but most likely not at the spot you were filming.

my website: http://www.outriggercanoe.com

Cheers,
Mike

Post by **fogo** » Mon Mar 03, 2008 8:09 am

Nice work Mafishus, getting exposure bang on in this situation can be difficult, especially when your subject is wearing a black wetsuit and there's lots of whitewater. You did well tho, you picked up some nice detail! Look foward to seeing some more footage,

ade