The "feel" and use of different focal lengths...

[splproductions]

Derrel made a reply to a post a bit ago that I didn't understand - so rather than derail that thread I thought I'd start my own.

Derrel said: "To simplify what he [Thom Hogan] said: 85mm on FF is almost perfect for portraiture at 8 feet; 50mm on DX (aka 1.5x Nikon) produces what he describes as "an awkward crop", and forces the photographer to make some compromises that are, basically, undesirable."

A 50mm on DX is a 75mm equivalent ff. So we're comparing 75mm to 85mm. I understand that different focal lengths affect how space is rendered (compression, etc), but I can't imagine how 75mm would be "awkward" and cause you to "make compromises", but 85mm is great. It's only 10mm difference.

I'm not asking this to be combative - I'm just trying to learn how the difference between these two scenarios can have any real impact on your photo shoot or your final product.

 

[The_Traveler]

I'm not Derrel, a fact that both he and I are pleased with, but I think that the 3:2 aspect ratio is awkward for portraits at least 75% of the time.
When I shoot in portrait aspect, I compose for 4:5.

 

[Derrel]

HERE'S a nice chart that illustrates what Lew was referring to, in terms of the aspect ratio of the final image, and how focal length is related to that. Equivalent Lens Focal Lengths For Different Film Sizes - photo.net

 

[enzodm]

I too would be interested in a better explanation of Thom Hogan sentence (maybe with a link to the original?), thanks. The_Traveler comments makes sense to me, however since FF and APS-C are both 3:2, does not seems to have much to do with the original question (or, if it has to do, I even more need a better explanation ).

 

[table1349]

A good resource: Digital Photography Tutorials

Go to the lens section.

 

[enzodm]

A good resource: Digital Photography Tutorials

Go to the lens section.

where in particular? There is the whole story since Adam photographing Eve in that section.
The original question is related to why 85mm on FF is perfect, while 50mm on DX/APS-C is awkward (to simplify).

 

[Helen B]

I think that all Thom is saying is that he finds 75 mm (on full frame) too short for portraits, but 85 mm is just right. Therefore, using a 50 mm on a 1.5x crop camera is not his ideal portrait length, because it is too short. The implication is that he would prefer a 58 mm or 60 mm maybe. I'd like to see the original quote, however.

 

[fjrabon]

I think that all Thom is saying is that he finds 75 mm (on full frame) too short for portraits, but 85 mm is just right. Therefore, using a 50 mm on a 1.5x crop camera is not his ideal portrait length, because it is too short. The implication is that he would prefer a 58 mm or 60 mm maybe. I'd like to see the original quote, however.

Yeah, on dx the 60mm is about perfect. Why I think the tamron mm f/2 is the best portrait lens for dx.

 

[Dikkie1]

Derrel said: "To simplify what he [Thom Hogan] said: 85mm on FF is almost perfect for portraiture at 8 feet; 50mm on DX (aka 1.5x Nikon) produces what he describes as "an awkward crop", and forces the photographer to make some compromises that are, basically, undesirable."

A 50mm on DX is a 75mm equivalent ff. So we're comparing 75mm to 85mm. I understand that different focal lengths affect how space is rendered (compression, etc), but I can't imagine how 75mm would be "awkward" and cause you to "make compromises", but 85mm is great. It's only 10mm difference.

Your focal length stays physically the same but you'll crop your field of view in the case of a DX camera... ok, for just that -1.5 x (focal length equivalent).

But the difference in focal length has aswel its consequences on the depth of field.

Shoot the same object with a 85mm and a 50mm (both at FF), both at the same aperture of F 2.0 and you'll see the difference.
For me personally, the 85mm will have a more beautiful depth of field, elegant bokeh. For others it can be the opposite, that's taste.

 

[enzodm]

I think that all Thom is saying is that he finds 75 mm (on full frame) too short for portraits, but 85 mm is just right. Therefore, using a 50 mm on a 1.5x crop camera is not his ideal portrait length, because it is too short. The implication is that he would prefer a 58 mm or 60 mm maybe. I'd like to see the original quote, however.

this is what I thought at first, but maybe is a too simple explanation - that "awkward crop" lets me doubtful. I lost some time looking for the right post on his blog, but no luck - Derrel? Please, sources...

 

[Derrel]

I think that all Thom is saying is that he finds 75 mm (on full frame) too short for portraits, but 85 mm is just right. Therefore, using a 50 mm on a 1.5x crop camera is not his ideal portrait length, because it is too short. The implication is that he would prefer a 58 mm or 60 mm maybe. I'd like to see the original quote, however.

DX Month, Week 1 at bythom.com


The following is the Oct. 5, 2012 entry by noted author,instructor,and analyst Thom Hogan, during his month-long "DX Month" series of observations published on one of his web site.

And Here's Something Else Nikon Won't Want to Hear Oct 5, 2012--Many of the emails I get have either an assertion or a question about using FX lenses in place of missing DX lenses. This clearly is what Nikon wants you to do, and is probably why they haven't produced a DX portrait lens, amongst others. But consider this: portraiture is partly about perspective. A head and shoulders shot of a bride-to-be is often in the 85-105mm range for a reason: it provides a very flattering perspective. Nikon wants you DX users to use an FX 50mm f/1.4G for this. But let's see what happens. When I shoot an 85mm at 8' on FX I get a cut-off just above the elbows, a traditional chest/shoulder/head view. With a 50mm on DX at 8' I am framed slightly below the waist and well below the elbows; in fact, it's an awkward framing. I have to move in nearly two feet to get the same framing as FX, but now my perspective is starting to not be flattering on the model. So what FX lenses do we have that can put us in the right position and perspective? The 60mm f/2.8 Micro-Nikkor, which is going to be too sharp for most portraiture (unless you like doing lots of skin fixing after the fact) and not allow us as much DOF control. The 70-200mm f/2.8 (or any other f/2.8 lens that can get us to 70mm). Same comment about DOF control. Back in 2001 (yes, over ten years ago; consider that in considering the DX portrait problem), I wrote that the perfect FX lens for portraiture on the DX DSLRs that Nikon made was...the 58mm f/1.2 NOCT. Almost immediately every used NOCT on the market disappeared and the price sky-rocketed. Partly because every pro shooting portraits realized I was right. It's 87mm equivalent on DX and it's got that fast aperture, a fast enough aperture that we almost get to 85mm f/1.8 FX equivalence on a DX body. To this day, it still is the best choice for a DX wedding shooter looking for that classic 85mm portrait look. Did Nikon notice? No. Did Nikon ever release a true DX portrait lens? No. This is just one of the reasons why I don't think that "just use FX lenses" is the right answer to supply DX shooters. It's a hostile answer that tells photographers that "We don't care what you think about perspective, just do it our way and shut up." How's that for customer support? Professional photographers understand and care about perspective, depth of field, and all the other elements that allow them to make their imagery exactly as they want it. If they're using DX cameras, the company that makes them doesn't care about those things nearly as much. That's being "at the heart of the image"? That's a focus on what's necessary to be the leader in imaging? I don't think so, because it doesn't actually show much understanding of what makes an image what it is. Now, the fan boys will get all upset by the last two paragraphs and tear into me on the Internet. Just ask yourself this: when was the last time those fan boys shot great images that spoke to you? If photography has become just about resisters and capacitors and ASICs and image sensor specs, then photography is no longer photography. [Climbs ladder down soap box, holsters guns, turns off amplifier, and watches fireworks]

 

[enzodm]

Thank you Derrel. So, Helen was true. But, splproductions, do not worry much: it's more bashing Nikon (and possibly Canon too) for focal lengths selection for crop bodies than a strict indication. Hogan says that, as the classical 28-80mm in ff has been translated to 18-55, also other focal lengths should have been prepared specifically for crop bodies, if thinking at their usage, instead of just replicating FX lenses.
In some sense, it is what my Sigma 50-150 does (and Tokina 50-135 too), vs. classical 70-200 in full frame.

 

[Derrel]

INterestingly, on November 22, 2012, Nikonrumors.com wrote a short item on TWO Nikon 58mm f/1.2 prime lens patents that the company had filed in Japan...that's right, patents for TWO brand-new 58mm f/1.2 Nikkor lens designs...

Hmmmmmm.....

New Nikon 58mm f/1.2 lens patent | Nikon Rumors

With old 58mm f/1.2 Noct-Nikkor lenses fetching three to four thousand dollars on the e-Bay market, I think Nikon executives might have sensed a niche where a high-priced prime stands a chance of gaining some serious traction. Same with the Voigtlander 58mm f/1.4 lens, which has also sold quite well, even with some 'issues'.

 

[BrianV]

Nikon never made a 75mm focal length lens, but other manufacturers have- including Leica. The Nikkor 8.5cm f2 put Nikon "on the map", and they have always made great 85mm focal length lenses. It's probably what he is used to. I prefer an 85, grew up using Nikons.

Nikon also made the 55mm F1.2 that is sharper across the center 2/3rds of the image than is the 50/1.4. On a DX camera, you get the sweet spot. Nikon also made the 58/1.4, which would be a nice portrait lens on a DX camera. It was never made in AI mount, would have to be modified. The Noct-Nikkor 58/1.2 was considered a specialty lens, introduced in 1976 and optimized to eliminate some optical aberrations. It was optimized for 10LP/mm work. Using it to replace an 85mm portrait lens seems like overkill when alternatives that cost 10% as much are available.

The page on Nikon Rumors: Nikon made an F1.0 lens for industrial work, not for photographic use. Nikon made a 50/1.1 for the Nikon rangefinder camera. I've used one, it is a soft lens. About 1/2 the weight of my Canon 50/0.95. These cannot be used with SLR's. Nikon also made a 55/1.2 "Nikkor-O" for use on Oscilloscopes. Some of these are modified for use with mirrorless cameras.