1. ## Hasselblad Lens magnification factors and 35mm equivelants

With the 35mm lens equivalents....

I'm currently using a film back with a view to go digital, I've been stuck about buying the 100mm for a while as I'm used to 85mm on the 1Ds3.

Now, the way I'm reading this chart is that a 100mm lens on my H1, on my film back will give me a 35mm camera equivelant of 67mm (The reason I'm holding off the purchase as it's too short) but, with a digital back like a 48x36 back which has a magnification factor of 1.1x will make the lens and digital back combo an equivelant of 110mm on a 35mm camera?

If this is true, I don't need to buy a 100mm lens as the 80mm I already have will become 88mm. But the chart says the 80mm is 50mm?...ACK!

2. ## Re: Hasselblad Lens magnification factors and 35mm equivelants

The crop factors are in relation to 6x4.5, not 35mm. So a 100mm will give an equivalent FoV of a 67mm in 35mm.

I would just work in angular magnification. Divide the focal length by the format diagonal. 35mm has a diagonal of 43mm. A 90mm lens is about 2x--90/43. So if I want a 2X on my 645d which has a 55mm diagonal, I need a 110mm lens--55x2.

3. ## Re: Hasselblad Lens magnification factors and 35mm equivelants

You just confused me even more with the second sentance haha.

So for 85mm I will need the 150?

4. ## Re: Hasselblad Lens magnification factors and 35mm equivelants

The chart is maybe a little confusing, but I think that you do need the 150. The chart says that on 6x4.5 film, the 150 mm lens is roughly equivalent to and 85 mm lens on 35 mm film. The chart then says that with a 1.1x factor digital back, a 150 mm lens is equivalent (in 645 terms) to a 165 mm lens (i.e. 1.1 x 150 = 165), which in 35 mm film terms would be about 93.5 mm (85 * 1.1). So it seems that a 150 mm lens is probably what you want.

5. ## Re: Hasselblad Lens magnification factors and 35mm equivelants

That's what I was thinking. I tried shooting headshots today with the 80mm and tbh I was far too close to the customer. The 100 is only and additional 20mm and in MF terms that's not a lot.

I shoot at 1.8 a lot in 35mm, I've read that a 2.8 lens is like a 1.8 so hopefully the HC 150mm at 3.2 won't be an issue. Although the Mamiya 150mm 2.8 is calling. Which will involve changing my setup.

Is there a conversion chart for apertures also? Thanks guys for helping.

6. ## Re: Hasselblad Lens magnification factors and 35mm equivelants

On a 645 body with a 48x36 sensor, to have the equivalent of your 85mm Canon lens you will need a 120mm lens (121mm actually...)

Yair

7. ## Re: Hasselblad Lens magnification factors and 35mm equivelants

Hi Yair, really? But the 120mm is only 65 on the chart.

Not questioning you at all just don't understand how it works.

(I emailed your guy btw but never heard back).

8. ## Re: Hasselblad Lens magnification factors and 35mm equivelants

Hi chris

I know this will eat into your budget for the back. But have you considered hiring a back along with some extra lenses, to see what will and won't work in your studio?

That would give you a better idea, rather than trying to work it out via charts

9. ## Re: Hasselblad Lens magnification factors and 35mm equivelants

Yes, Yair is correct.

I use this nifty calculator courtesy of Capture Integration to work out all my lens conversions.

http://www.captureintegration.com/20...nt-calculator/

10. ## Re: Hasselblad Lens magnification factors and 35mm equivelants

You can try the Excel sheet from CI's website (scroll to the bottom of the page. A 48x36 back would be a little bit smaller than the P45/ P25 @ 49x37mm

11. ## Re: Hasselblad Lens magnification factors and 35mm equivelants

Chris,

This is always a little tricky. I posted a chart: post #6 of http://forum.getdpi.com/forum/showthread.php?t=9740 . Short answer is it depends on size of sensor. In addition, I've found you don't always use the same "equivalent" lenses for headshots due to shallow depth of field of mfd. When I use my 210mm on my H3d2-39m (roughly equivalent to 155+-mm on full frame dslr) at 7 feet from subject at f8, my dof is less than 2.4" and at f11 it's only up to 3.3" which is the same dof as a 155mm on full frame dslr at f8.

12. ## Re: Hasselblad Lens magnification factors and 35mm equivelants

Originally Posted by carl-b
Hi chris

I know this will eat into your budget for the back. But have you considered hiring a back along with some extra lenses, to see what will and won't work in your studio?

That would give you a better idea, rather than trying to work it out via charts
Hi Carl, I know what I need for the studio. 85mm basically. It's all I use for headshots. All my other work is weddings which is strictly 35mm

Originally Posted by yaya
You can try the Excel sheet from CI's website (scroll to the bottom of the page. A 48x36 back would be a little bit smaller than the P45/ P25 @ 49x37mm
That's ace, thanks.

Originally Posted by David Schneider
Chris,

This is always a little tricky. I posted a chart: post #6 of http://forum.getdpi.com/forum/showthread.php?t=9740 . Short answer is it depends on size of sensor. In addition, I've found you don't always use the same "equivalent" lenses for headshots due to shallow depth of field of mfd. When I use my 210mm on my H3d2-39m (roughly equivalent to 155+-mm on full frame dslr) at 7 feet from subject at f8, my dof is less than 2.4" and at f11 it's only up to 3.3" which is the same dof as a 155mm on full frame dslr at f8.
I saw that the other day David. I'm putting the film back through it's paces this week (film yet to be developed, all with the 80mm) It'll be good to see what the DOF is like.

14. ## Re: Hasselblad Lens magnification factors and 35mm equivelants

Originally Posted by gazwas
Yes, Yair is correct.

I use this nifty calculator courtesy of Capture Integration to work out all my lens conversions.

http://www.captureintegration.com/20...nt-calculator/
I wish the answer was an absolute with only one "right" answer. But there are several nuances to consider.

Aspect Ratio Matters
First, our calculator only considers the diagonal of the frame (regardless of aspect ratio). Many of our clients don't like the 3:2 aspect ratio for vertical headshots and crop almost all of their 35mm dSLR headshots to 4:3. If you always crop to 4:3 your 85/1.2 is roughly a 135mm on a 36x48mm sensor (aka 1.1 crop MF) since the MF will capture 4:3 natively.

The X Factors
When selecting a mainstay portrait lens the focal length (relative to sensor size) is very important but it's not the whole story. The working distance to the model (and it's impact on both you and the model), the draw, the ease/speed/accuracy of focusing, the max usable/sharp aperture, the out of focus rendering, and even the physical size of the lens (how heavy, emotional impact: intimidation or intimacy) all play a role in which lens is the best overall mainstay for you.

Lens Niches
It's also not the case that the lens manufacturers all seek the same priorities at the same equivalent focal lengths. The Canon 85/1.2 and the Phase One 120/4 AF Macro are not duplicates of each other. If anything the 150D/2.8 or 110LS/2.8 are closer to the 85L as far as intended use/market goes.

Biased By Limited Selection?
You love the 85L, but you selected it amongst lenses fairly spaced out (assuming you were choosing from amongst L series primes). The 50L was presumably too short and the 135L presumably too long, but if you were instead handed a 75mm, 80mm, 85mm, 90mm, and 95mm would you still have picked out exactly an 85mm?

You've concluded that 85mm is ideal, but maybe instead you should consider the equivalent of a 50L equivalent too wide and the equivalent of a 135L too long and be open to anything between those two.

Budget Matters
The Phase One 150/2.8 D (approx. US\$3.5k) is my favorite lens on any system. For some that lens falls well within their budget - for others it does not. If you are trying to stick to a tight budget you'll find many on the forum ready, willing, and able to help recommend legacy lenses like the Mamiya 150mm f/3.5 which are darn good but cost a fraction as much.

The [lens which is the closest mm equivalent] and the [lens which fits your budget] may or may not be the same thing.

Moral of the Story
So by all means use our calculator to get a sense of the numeric equivalency (that's why we made the calculator after all) but if possible, don't stop there. The numbers are important but there is no substitute for your own hands on experience actually taking pictures.

A better overall question might be "I shoot studio portraits with a 5DII and 85mm and love the results. Here are a few of my favorite portraits I've taken with this rig [insert a picture or two]. Here is what I love about them [insert reasons here]. I'm thinking of switching to a 36x48mm sensor and am considering X platform. My budget is around [insert budget]. Based on this information what lenses in those systems would you suggest I look at?"

Then take those responses and do anything you can to get the suggested lenses in your hands to see how they feel to you. Full disclosure: this is a very biased/self-interested suggestion to make since, as a dealer, we frequently set up such evaluation rentals for our customers across the country.

Phase One P40+ with 150mm at f/3.2

Doug Peterson (e-mail Me)
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