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Maple
30-Mar-2012, 05:27
Hi guys,

Love the forum guys thanks, its a true gold mine of information! anyway

I am an aerial photographer with a landscape and wildlife focus. I shoot both digital and 6x17 and currently I am having a really hard time setting up the 6x17 format to do all the things i need it too. I really need some advice on a wide lens (below 140mm) that will work the way i need it to work which i find is the opposite to what these lenses are built for. I need shutters speeds at a minimum of 1/250 on velvia 100 or at a maximum prov 400x with as little as possible light fall off for reef and tropical island scenes! I know its a big ask. one thing on my side is that the dof is not critical. I shoot at infinity all the time so can work at f4.5 if the lens will allow but as you know they dont.

I have been using a Nikkor 4.5 SW at f5.6 - f8 and seems to work well except it has terrible fall off. A center filter could just work with prov 400x but its really at its limits and would like to stick to the velvia if possible!

So what i really need to know is what if any lens would work the best for this application, something that will preform well close to wide open (without mechanical Vig) has no really noticeable light fall off has a copal 0 or 1 shutter (3 is not fast enough) and is wider then 140mm?

Any advice would be greatly appropriated!! and i mean that! it has been a long and expensive road.

cheers
ben

Dan Fromm
30-Mar-2012, 05:55
Ben, it all depends on the focal length you want to use.

I don't, off the top of my head, know the size of your 6x17 roll holder's gate. If it is 56x170, the diagonal (= normal focal length for the format) will be approximately 180 mm.

With a 140, the half-angle covered (theta) will be around 33.5 degrees and the corners will be around half a stop down from the center. I assume falloff as cos(theta)^4, some lenses do cos(theta)^3.

With a 110, around a stop and a half.

With a 75 (a 75/4.5 Biogon won't quite cover 6x17), 2 (Biogon) to 2 1/2 stops (most others).

Schneider and Rodenstock publish falloff curves for their current LF lenses. Look 'em up, curse your cruel, cruel fate.

Joshua Dunn
30-Mar-2012, 11:14
What is the focal length of the Nikkor SW you are using now? I use my 120mm f/8 Schneider Super Angulon all the time on my 6x17 but I use a center filter. Have you looked at the Schneider 110mm Super Symmar XL? Again you would probably need a center filter.

I have never used one but a Schneider 120mm Apo Symmar L (I think it would have to be the never "L" version to really cover) will cover 6x17 but with little movements. The lack of movements doesn't sound like an issue for the way you are shooting. I mention that lens because it is not a traditional wide angle lens so it should have less light fall off but will cover 6x17. See if you can borrow or rent one and test it.

How wide did you want to go?

-Joshua

Dan Fromm
30-Mar-2012, 12:55
I just looked at Schneider's data sheets. The Apo Symmar L covers 189 mm, a bit more than needed for 6x17; at the edge it is down more than 1 stop from the center. The Super Symmar XL has much much more coverage, at the edge of a 180 mm circle is down around three quarters of a stop from the center. [edited to correct an arithmetic error in converting % down to stops down. I'm glad no one pounced on me for it}

So much for the conventional wisdom as expressed by Joshua.

Maple
30-Mar-2012, 15:09
Wow thanks for the fast reply guys! Sorry Joshua i didn't mention, it is a 90mm nikkor.

So dan what you are saying is if i use anything around 140mm i should only experience 1/2 a stop in fall off? Because half i could deal with. At the moment its about 1 and 1/2 and i loose too much quality with returning it in post.

I cant really use a CF because at f/8 it will barely work as i understand it.

Does excess coverage help? would a 135mm with 200mm coverage still leave me with 1/2 a stop fall off? I am using the http://www.largeformatphotography.info/lenses/LF6x17cm.html charts to narrow down my choices.

Thanks Again for the fast and timely advice.

ben

Maple
30-Mar-2012, 15:51
Sorry i forgot to ask, the image circle stats are at f22. Can i pay any attention to those figures when i will be almost exclusively shooting at f11 and below.

ben

Dan Fromm
30-Mar-2012, 16:22
Um, ben, are there modern 140 mm lenses that will cover 6x17? And what focal length do you need?

Re coverage, if you're thinking about modern lenses from Rodenstock and Schneider, in alphabetical order, look at the MTF curves. I think they're given for a range of stops, I know, having just looked at some, that the illumination curves are. The MTF curves are a guide to coverage.

Maple
30-Mar-2012, 16:34
Thanks mate i will mull over the mtf data, there are 135mm and 150mm lenses that will cover 6x17 at f22, as for what i need, wider would be better but i have to find a balance between fall off and wide angle. 135 if only producing 1/2 a stop of loss will be great.

thanks again.
ben

Peter York
31-Mar-2012, 10:03
A few suggestions:
1. Experiment with pushing velvia 1/3 to 2/3. This might tip the balance, allowing you to use a center filter.
2. With E-6 and 1/250, the condition and care of the shutter will be important. Schedule regular CLA's, and/or buy a shutter speed tester.
3. Take a look at the Schneider 110mm XL. An outstanding lens, nice and wide with less falloff than the 90mm lenses.

Maple
2-Apr-2012, 01:41
Hey Thanks peter i will give that a try.

I did have a look at the 110xl but its really expensive! I guess if all else fails i will invest!

thanks again

Peter York
2-Apr-2012, 08:47
Yeah they are expensive, but from all accounts I've seen the price (used) is worth it.

Check out the 135mm Wide Field Ektar. Its much less expensive. However you have to be careful with older, used lenses as their shutters may not achieve the 1/250 you are aiming for.

If you limit your lens range from 90 to about 150, I suppose you could get a speed graphic and attach the 6x17 back to the Graflok, which would let you shoot up to 1/1000 with the focal plane shutter. Longer focal lengths with this setup will crop the 6x17 image (I'm not sure at what focal length the cropping begins).

John Kasaian
9-Apr-2012, 21:45
IIRC the lens Peter Gowland recommended was a 200mm Nikon M, but the last time i spoke with him must have been 10 years ago. If a 200 will cover 6x17, I'd at least give it some consideration.

Lachlan 717
9-Apr-2012, 22:23
Ben,

I've used the 110mm on 6x17 without a CF and didn't think that I needed one. See below.

71711

Where are you based?

Maple
9-Apr-2012, 23:14
Hey thanks guys, Lachlan i am based in QLD Australia, Nice shot, seems to be ok hey, pretty dark in the right but still nice.

I might give the 110 a go, if that fails the 150, such a big image circle!

Thanks again everyone.

Lachlan 717
9-Apr-2012, 23:19
Nice shot, seems to be ok hey, pretty dark in the right but still nice.


Thanks.

There was a pretty big storm brewing off to the right, so don't see that as fall-off. Perhaps look top and bottom left for more indicative information.

This is the only lens that I regret selling...

Maple
9-Apr-2012, 23:40
Yer alot of people say they wish they never sold that lens.

Sorry to split hairs here because i really appreciate your example but isn't there a counter effect to the fall off in the right of the frame because the sun is setting there? I would imagine without the fall off that side of the shout would be very bright?
Let me know you thoughts

cheers

cosmicexplosion
10-Apr-2012, 03:31
thats a pretty shot lachlan, looks a bit like you were flying.

Lachlan 717
10-Apr-2012, 04:36
Thanks, Andrew.

Not flying; just poised on a cliff...

alexn
10-Apr-2012, 19:57
the 110xl is the answer. you need 179mm circle, the 110xl has over 340mm from memory (at f/22) but being logical I can't see it being less than 180mm F/8 or there abouts.... Pricey, yes, but if you want to do the job properly, thems the brakes.... A friend of mine has a 110XL on his 6x24, At F/16 he uses a center filter, but 6x24 is a lot bigger than 6x17

Lachlan 717
10-Apr-2012, 20:15
the 110xl has over 340mm from memory (at f/22)

Quoted by Schneider as being 288mm@f22.

However, this is still a whole lot bigger than the 6x17 requires, and negates to a certain level the need for the CF.

The Nikkor 120mm SW has about 312mm coverage, but I have not used one, so cannot comment on the need for the CF.

alexn
10-Apr-2012, 21:31
I must have confused the two. I was looking at lenses to cover 6x17 just the other day on that chart you linked to me a while back. Must have confused numbers.. In any case, your shot of the the 12 apostles shows that the 110xl is more than capable on 6x17 without the need of a CF Thats a pretty high contrast scene, and if there was falloff, you would think it would be fairly obvious.. To be honest, for arieal shots of reefs etc, I like a bit of vignetting. I've seen plenty of great shots of the barrier reef with vignetting that really draw you to the subject. Worth thinking about.

Maple
11-Apr-2012, 04:09
Hey thanks again guys, wealth of knowledge! Yer i have been looking at the http://www.largeformatphotography.info/lenses/LF6x17cm.html guide and the XL is about as good as it gets. I will have to buy one and see how it goes. I know what you mean about the pleasing vignetting. I am trying to do a bit more abstract work focusing on patterns more then a point of focus however, that's why i am been so painful and picky. :/

Anyway thanks again chaps you all certainly know your stuff.

let me know if you see a 110XL on the market.

cheers

cosmicexplosion
11-Apr-2012, 04:13
there a 110xl on ebay from bulgaria, $176 at the moment... i might try and out bid you...just kidding.

Tell me maple, do you fly in a plane or a chopper, and who pays for it?

I am thinking of getting a paramotor next year, to get a bit of levity.

Maple
11-Apr-2012, 14:26
Hahah yer i am watching that item.

Yer i have been through the paramotor idea, I have been flying a paraglider for about 7 years now and on paper the paramotor looks like the perfect solution but it didn't work and It nearly killed me! Apart from the obvious restrictions with a very tiny weather window of operation, and very shot flying rang, a paraglider needs to be flown with your hands near or at close to the toggles in-case of collapse (youtube paraglider collapse) not a good look! Anyway now i have a mate with a microlight (trike) bigger window of operation, further range and far less life threatening :)