Bokeh! 35mm vs 6x7

Mainecoonmaniac

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You're correct Sir


Yes I meant field or angle of view. And yes, 35mm is slightly wider than 6x7 format. It's just an approximation.
 

lxdude

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John Koehrer

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lxdude said:
Which is why 50mm- 58mm is considered normal instead of 43mm.
Click to expand...

I'd argue that in most circles the diagonal of the film is the determent factor in defining "normal" not focal length..

35mm=~43mm
6X6cm=~100mm
6X9=~110mm
4X5"=135mm etc.
 

lxdude

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John Koehrer said:
I'd argue that in most circles the diagonal of the film is the determent factor in defining "normal" not focal length..

35mm=~43mm
6X6cm=~100mm
6X9=~110mm
4X5"=135mm etc.
Click to expand...

Yes. What makes the 50mm range appear "normal", and a 43mm seem slightly wide, is the format. The 3:2 ratio of width to height makes the 135 frame look wider than 5:4, 4:3, or 1:1.
This is most obvious with panoramic formats. My 645, in full format of 42X56 gives a very different "look" than with the 35mm pano back with the same lens. The image with the pano back can even give the appearance of being a wide shot with the 75mm lens, a "short telephoto" length on the 135 format and "normal" on the 645.
 

Mainecoonmaniac

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As for me..

lxdude said:
Which is why 50mm- 58mm is considered normal instead of 43mm.
Click to expand...

My eyeballs see a bit wider than 50mm focal length. I think my vision is more between 35-43mm. Sometimes, 50mm makes my shots feel tighter than what I see. 35mm lens feels more natural for me. Love the Bokeh of my 50mm 1.4 wide open though.
 

lxdude

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Colonel, welcome to APUG!
To get an idea of how the bokeh of different lenses looks, check out flickr. Put in a specific camera and lens, and there is likely a collection of photographs from that combination there. Doing a general search for "(camera) (lens) bokeh" may well be productive.
There is no singular subjective judgment of bokeh. Some people like "swirly" bokeh, which gives others a headache. Some people just don't like bokeh which to their eye is too "smooth".
 

artobest

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Here is a striking example of unconventional (by modern standards) MF bokeh. Rollei (Zeiss) Planar 80/2.8 on an SL66SE. It's not smooth and buttery (the current buzz words) but it's pleasing in its own way ...
 

Arcturus

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Of all the lenses I have I actually like the oof area of the uncoated 105mm f3.5 Skopar on my antique Voigtlander Bessa folder. I have Tessar-type lenses for other cameras, but this one has a nice look that I like the best.

Untitled by mariner04, on Flickr
 

E. von Hoegh

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Mainecoonmaniac said:
I was looking for the "perfect" bokeh and bought a LensBaby. Didn't workout. I sold it. I'm still wanting a Petzval lens, but it's out of my budget. Sure makes a beautiful swirly blur.
Click to expand...

Petzvals were designed as a fast portrait lens. When used as intended, there are no swirlies - the focal length was long for the intended format, and all the swirly stuff landed on the insides of the camera. The central zone of a Petzval is very sharp.
 

Mainecoonmaniac

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That's why I lust after them..


Ah, but some day, I'll have one. I've got serious Petzval GAS.
 

polyglot

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This thread belongs in the bulshitters thread!

a) blade count is mostly irrelevant for bokeh because generally (unless there are very few) you can't count 'em in the image. There are lenses with few blades and beautiful bokeh (e.g. CZJ Flektogon 35/2.4 with hexagons)
b) the dominant factor for smooth bokeh in a traditional lens is the presence of spherical aberration. It dims the edges of the blur discs, thereby reducing hard edges
c) the ultimate bokeh machine is the Minolta/Sony 135 STF due to the presence of its apodisation filter. You get blur gaussians not blur discs, therefore absolutely NO hard edges in the OOF area. It's like taking a defocused image of a defocused image...
d) second choice are the sink-strainer lenses as seen on some MF systems
e) anyone who thinks poorly of Mamiya bokeh# - on the basis of half-remembered internet "wisdom" - needs a good slap.


# or any major brand. They all have "good" and "bad" lenses and if you stick to primes, the bad are few and far between. You can get horrific bokeh from super-zooms though - again with the correction of SA to enhance sharpness often causes nisen bokeh.
 

Mainecoonmaniac

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Really?

Didn't know that about aperture blades and Bokeh.
 

StoneNYC

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Also I have seen others mention the Mamiya Rz67(or RB67) but what about the RZ67 paired with the 110 f/2.8 lens? That will actually be fairly close to the 50mm (probably more like 58mm if my calculations aren't totally off and please correct me if I'm wrong) and the DOF would actually be shallower than the 35mm camera with a 50mm f1.4 lens according to Thomas' calculations in post #16

And the RZ67 series is really inexpensive right now compared to the Hassleblad with comparable optics for sure, the Mamiya RZ67 is a great system and also backward compatible with RB67 lenses. Both of which are inexpensive compared to others right now.

Please feel free to correct any errors I made.


~Stone

Mamiya: 7 II, RZ67 Pro II / Canon: 1V, AE-1, 5DmkII / Kodak: No 1 Pocket Autographic, No 1A Pocket Autographic | Sent w/ iPhone using Tapatalk
 

lxdude

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Mainecoonmaniac said:
Didn't know that about aperture blades and Bokeh.
Click to expand...

Yep.
Diaphragm shape only affects bokeh when the shape can be imaged to some degree in the picture. That is most noticeable with a distinct out-of-focus highlight, because it stands out. In fact, if a lens wide open renders Oof highlights as discs with very bright edges, any shape of diaphragm may well produce a more pleasing bokeh as it cuts off the outside of those discs, leaving a more even Oof highlight in the shape of the diaphragm.
 

polyglot

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A 110/2.8 on 6x7 is approximately the same (in FOV and DOF) as a 55/1.4 on 35mm. There's no easy comparison because the aspect ratio differs: when you frame, do you compare the long side, short side or diagonal?

A simpler way is to look at the physical aperture size - that will give you a good idea of how much bokeh there is for similar fields of view. 110/2.8 = 55/1.4 = 39.3mm, and 50/1.4 = 35.7mm.

So many more 35mm systems were made though that good glass for them is easier to find. But if you want large, creamy smooth prints, you need large negatives too.
 

Tom Richard

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There´s some good points in this thread. Generally i think photographers jump too quickly to simple conclusions on the subject. A given combination of lens/body/film (or sensor) will output different results between different photographers because the combination reacts differently within various light conditions. All optical constructions have their own unique signature which needs to be learned. In the digital era things have a tendency to drown in mathematical charts and tests. Some Carl - Zeiss lenses are known for their "3D" rendition of light. I suspect this cannot be measured and analyzed although its certainly real (albeit subjective). In my personal experience its all about the optical signature of a specific lens and how it fits each and every photographers unique style.

Also, like polyglot says, large negatives is key!
 

StoneNYC

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Thanks Polyglot,

Good to get such precise info, my point was that it was very much the type of lens the OP was looking for if he/she chose a MF system.


~Stone

Mamiya: 7 II, RZ67 Pro II / Canon: 1V, AE-1, 5DmkII / Kodak: No 1 Pocket Autographic, No 1A Pocket Autographic | Sent w/ iPhone using Tapatalk
 

JBrunner

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I have personally found comparing DOF between different formats to be a bit obtuse. Not because they are equivalent or non-equivalent, but because simply by changing the subject/ background to film plane distance within what one can reasonably crop, one can alter apparent DOF and bokeh fairly significantly.
 

msbarnes

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IDK as you can see this can get quite tricky and overly complicated.

I think that the differences in bokeh within the same format is mostly for photo nerds.

Keep in mind that if you get the Mamiya then you wouldn't be able to focus as closely (or as accurately) as you would with an SLR/TLR. Getting in closer helps decrease the DOF.


Untitled by Michael_Sergio_Barnes, on Flickr


Untitled by Michael_Sergio_Barnes, on Flickr

Not razor thin but these are up close at f4 with Rolleinar 1's (Rolleiflex close up lenses). f2.8 at these distances is too thin for me.
 
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PaulMD

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"35mm" doesn't have better bokeh than "6x7". What 35mm lens and what 6x7 lens? A triplet is going to have a lot jitterier bokeh than a double-gauss type no matter the format size.

Generally speaking though the bigger the format the shallower the depth of field for a given field of view. This is because of the focal length - a 90mm lens is a 90mm lens no matter how you slice it. You can stick that 90mm on a 35mm camera and it will be a long lens (different from being a telephoto!), or if your lens covers 4x5 then it will be a wide angle at that format. A P67 105mm f/2.4 is going to have the same depth of field (approximately) as a Nikkor 105/2.5 if you were to shoot them head to head on 35mm - it just has the capability to cover a larger format. Now, if you were to get an equivalent lens on 6x7 - say a 200mm - then for an equivalent f-stop (f/4 on the 105mm, f/4 on the 200mm) there will be shallower depth of field in comparison, because the focal length is longer.

The most succinct way to put this is that bigger formats require longer focal lengths for an equivalent field-of-view, and longer focal lengths have shallower depth of field - period.

And remember - these cameras were used by professionals in their day, pretty much any of them is good enough for amateur work.
 

lxdude

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One way to illustrate what PaulMD saying is to think of a real-world example -the different format cameras Pentax made. Pentax made an adapter to put 6X7 lenses onto the 645. They made an adapter to put 6X7 lenses onto K-mount. A 200mm f4 lens for 6X7, when adapted to 645 or to K-mount cameras, will give the same magnification and Dof with each as the 200mm f4 lenses Pentax made for those mounts.
 

StoneNYC

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I think you're incorrect about the Mamiya, a Mamiya RZ67 is SPECIFICALLY designed with bellows so it can get SUPER close. MUCH closer than a TRL.


~Stone

Mamiya: 7 II, RZ67 Pro II / Canon: 1V, AE-1, 5DmkII / Kodak: No 1 Pocket Autographic, No 1A Pocket Autographic | Sent w/ iPhone using Tapatalk
 
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