Leica M lenses equivalence on M8

[jorge_saravia4]

Hi every one (sorry for any English mistake),

 

I am a MP user and have 24/2.8 asph, 35/2.0 asph, noctilux and 50/2.0. I know

the M8 has a crop factor of 1.33, that turns the 50 mm in a +/- 67 mm lens, or

the 24 mm in a +/- 32 mm lens, that in terms of focal lenght. But since a 24 mm

has a different perspective and DOF than a 32 mm, for example (I know there is

no 32 mm M lens so it will be a 35mm), I am not quite sure if the 24 mm on the

M8 "equals" a 32 mm on a MP , or a 21 mm on a M8 (like the new

trielmar) "equals" a 28 mm on the MP, that in terms of perspective, DOF,

and "visual composition".

 

Does any one have done any comparison regarding what a M8 sensor "sees" vs what

a 35 mm area film (or sensor) "sees" using the same lens?, is there any real

difference ?

 

Thanks in adavance for your comments

 

Jorge Saravia

[Troll]

It appears that you don't understand the fundimentals here. All the "crop factor" means is that the image you will get with the M8 is like taking a full 24x36mm film negative, and cropping the center portion so that the "new" image is only 16x24mm, or 2/3s of the original image.

<p>The other way of looking at it is, instead of only a portion of the image you would be recording on film you would like the same image on the M8 sensor, you will have to use a shorter lens. For example a 50mm lens will produce the same image on film as a 33mm lens would on the M8 (just multiply by 2/3). It's all very simple, and very confusing.

[aplumpton]

Bill, the Leica M8 sensor is 27mm x 18mm; accordingly, you must multiply by

3/4ths instead of 2/3rds. Or by the ratio of 18mm (M8 sensor height) divided

by 24 mm (35 mm frame height), equal to 1 divided by 1.33 (whence the 1.33

X factor).

 

The half dozen and more sensor sizes are neatly shown on page 69 of the

December issue of Reponses Photo. Perhaps a canadian or American

magazine has depicted the sizes side by side, but I know not.

[tom5]

Jorge hit on an important point! If I put a put a 24mm lens on the M8 and a 32mm lens on

the MP, I'll get two photos that show the same field of view - The photos will look the same,

at first glance.

 

However, the photos will have different depths of field at the same f-stop. The 24mm lens

on the M8 will produce photos with a greater depth of field than the 32mm lens on the MP.

 

Optical physics can be strange and unintuitive sometimes.

[Bill Blackwell Images]

Look here:

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00Iqhm

 

The issue, as it turns out (if I understand your question correctly), is not all that complicated. The "crop factor" (so called) is aptly named. Your 28mm lens, for example, is simply "cropped" to 37mm.

[geoffrey goldberg]

The point about depth of field is (I think) quite valid. Thus, all the point and shoots have

short short lenses, everything is in focus at f8, and there is no bokeh. In fact, it is likely the

next generation of photographers will wonder about the vintage look of things out of focus.

 

Thus the pleasure of a rangefinder, fast lenses, and limited focus area.

[pablito_pistola]

Fast lenses, yeah...but you'd get the same result with fast lenses on a 35mm slr in terms of

shallow dof....

[pablito_pistola]

...oh, I don't mean to deny the pleasure of rangefinders...

[stuart_richardson]

The difference between full frame and 1.33 is not as big as you might think. If you are used

to shooting slides you probably are not shooting full frame anyway. The same would be true

if you print in the darkroom with a carrier that is not filed to leave a sloppy border, or if you

use a scanner that does not show the full frame. Yes, the M8 will still show less than most of

these, but it is not as small as many people think. I shoot with the DMR which is 1.37, and

you get used to the difference. Leica lenses are still fast enough to limit depth of field quite

effectively. A 28mm at f/2 or a 35mm at f/1.4 on the M8 is still going to have small depth of

field compared to most lenses that are as wide as they are. Certainly compared to most SLR

wide angles which are often covered by slow zooms. Anyway, it's just something to consider.

[jtdnyc]

I wonder if the depth-of-field issue isn't just a little more complicated than has been expressed above.

 

Yes, the 24 has more inherent depth of field than a 32. However, the image captured by the M8 is smaller than the image produced by a film M and therefore would require greater enlargement for a given print size.

 

Since bigger prints require a smaller circle of confusion to result in the same apparent depth of field, the d-o-f advantage of the shorter lens is at least partially negated by the need for bigger enlargement. Maybe not entirely negated, but the advantage would not be so great as the initial calculation of d-o-f might indicate.

 

Or so it would seem to me.

[larry_kincaid1]

Crop is easy to understand. But it seems to me that the concept of "perspective" in the original question is getting mixed up with depth of field. DOF refers to out of focus area, which seemed adequately described above by reference to f-stops of Leica lenses. The perspective issue refers to the distortion in distance that gets represented in the photograph. 45-55mm film lenses show the same perspective as the human eye. Long telephoto lenses (say 120-500 collapse or squeeze the distance so that a person in the foreground and a mountain or house in the backgound look closer together, and the wide lenses 15-28mm or so stretch out the distance in the photo so that the house/mountain in the background appear much further away than they appear to the eye. Likewise, portraits of faces look distorted with (film) wide angle lenses, so 65-125mm (film) lenses work better in that situation. What the original question seemed to asking is: To get the same kind of portrait outcome, I'm still going to have to use the 75mm-90mm Leica M lens as always. The "so-called" cropped "65mm" that the 50 gives me on the M8, or the "50" the 35mm Leica gives me on the M8 will still not work any better for portaits than they did on the M6/7's. Same logit for what you wanted from wide 24-28mm Leica lenses. You'll get the same perspective as before, but you won't get the "whole" photo you use to get from film. It will be cropped for you. So what . . . just "piece" two together in powerpoint to get a nice panorama and then crop it back again to get your old 28-35mm print? Just joking, but something is lost...cut out from what we're used to getting. To get it again on the M8 [let's call it width], you'd have to go one lens wider than before, but you'd also have to accept the extra distortion in perspective that comes with it. There's a reason why some wide angle Leica M shooters don't feel comfortable going wider than 35mm or 28mm and it's not just how wide the view is. If this is a totally wrong answer to the original question, someone please try to correct it in clearer language.

[Rob F.]

I don't believe anyone said this: perspective is determined by the camera-to-subject distance. Now, to cover the same subject area with a 32mm equivalent field, we must back away from the subject, just about as far as if we were shooting with a 35mm lens on an M6. The perspective will be the same in these two photos, because the camera to subjet distance was the same. This will be true even though the taking lens was marked 24mm in the case of the M8, and 35mm in the case of the M6.

 

I agree the DOF will be greater with the 24mm lens used on the M8, compared to a 35mm on an M6.

[Troll]

Remove foot from mouth! Sorry, Guys -- I was thinking of the usual 1.5 crop factor, not Leica's 1.33. For penance I shall fill my bathtub with ice cold Amidol, and sit naked in it.

[johnnycake_.1]

Late to the party, as usual...

 

For me, an unfortunate thing about the M8 and the 1.33 crop factor is that it, by necessity,

essentially "invents" new lenses. The family of "50s" becomes the family of "65s," the

family of "35s" becomes the family of "50s" and so on. I will adapt but where something is

gained, invariably something is lost.

 

I have always smiled, to myself, when, with film, I took a photo that didn't require any

cropping. Now, with the same lens on an M8, I will have stand farther away to achieve the

same perspective as the full-frame film version. I get a "kick" out of "rephotography" and

the M8 will complicate my fun.

 

Finally, perhaps this comparison is foolish, but I'm curious. How does the, for example,

Asperical Summicron 35/2, as a "50" on a M8, compare with the "genuine" Aspheric

Summicron 50/2 on a film camera? In a print, or on a monitor, can you see the effect of

the wider 35?

[aplumpton]

As most of the DSLRs and DRFs have a crop factor, perhaps the only problem

with the factor is simply the need to add another lens at the shortest focal

length of your existing lens range. Who really cares if you end up with an

effective 35 mm or 67 mm lens on the M8 with your 28 or 50? If you have a 21

it becomes a 28 on the M8 and your 35 becomes a 46 or 47. Ibid for the case

of DSLR crop factors (1.3, 1.5, 1.6, 1.7 or 2.0X). The CV 12 mm becomes a

nifty 16 mm at 1.33 X crop factor (some have tried this combo and find it quite

fine, at a hallucinary low price).

[kelly_flanigan1]

Crop factor is just a dumbed down term for folks who dont want to think in angular coverage; like folks did with 35mm attachments on TLR's decades ago. In movie work one thinks of what the angular coverage is need for each scene; then selects the lenses based on format.

[seth_honeyman]

For an interesting illustration of the effect of sensor size on depth of field, check http://www.dofmaster.com/dofjs.html There is a pulldown menu for most cameras (and thus sensor sizes) as well as the standard 35MM tables. There is a modest change from the 35MM tables, for example, when using the same lens on a canon 1d (which has a crop factor similar to the M8).

 

Regards - Seth

[larry_kincaid1]

"Who really cares if you end up with an effective 35 mm or 67 mm lens on the M8 with your 28 or 50? If you have a 21 it becomes a 28 on the M8 and your 35 becomes a 46 or 47." This is not correct and is inconsistent with what I said above. You do not get a normal perspective 50mm lens on the M8 by simply using a 28mm lens. You still have a 28mm lens--with its wide angle perspective and characteristics (slight elongation/distortion of distance from foreground to background)--but cropped. You won't get the same sized photograph/image out of it. If you use a 21mm or 25mm lens you'll be getting the perspectives of those lenses as well but cropped. So, the comment above is correct. To get the same sized photo and same perspective using a 50mm lens, you'll have to back up. But then you'll be further away from your forground object of interest (i.e., person, face, etc.). M8 users will just have to get used to getting slightly cropped images with the perspective they desire. But this is still better than some of the DSLR's 1.5 crop factor. If this interpretation is wrong, someone please correct it.

[stuart_richardson]

Larry, as much as it is logical to think you are right. The optical issues you describe are

not from the lens but from the camera to object distance. Yes, some wide angles have true

optical distortion as well, but this is a different issue. If you need proof of this

phenomenon, you need look no further than different formats. Digital point and shoots

with super zooms may only have a 50mm lens at the long end, but they will exhibit strong

telephoto effects because of the large camera to object difference. Same goes for large

format. The standard large format lens is about a 210mm lens, and that does not flatten

people's faces the way it would in 35mm if you are shooting with a 4x5...it draws similarly

to how a 50mm lens would draw on a 35mm camera. Yes, you will have less or more depth

of field with different lenses, but what you are describing is a property of perspective, and

it is not inherent in the lenses. If you don't believe me, try it. Take a shot with a 4x5

camera. It will look totally normal at 4x5. But if you take a crop down to the size of a

35mm negative, it will appear to have strong telephoto effects.

[stuart_richardson]

An even better way to test it would be to fill the frame with something using a 200mm lens

on a 35mm camera, and then use a 4x5 view camera with a 210mm lens to take a picture

also filling the frame with the subject. Of course you will have to be much closer with the

4x5. You will see that even though both lenses are around 200mm, the visual impression is

extremely different even though the depth of field is similar (at equal apertures). The 35mm

shot will appear to have compressed perspective between objects in the foreground and

background, while the 4x5 will appear normal. It is a function of camera to subject distance,

not of how many millimeters the lens is.

[mark_amos]

I can't recall where I read this simple explanation, but I could swear it was in the Retina Way, but I'll check. As I recall, if you take a picture of a house on a hill with a 50mm lens, and then you take the same picture from the same point with a 200mm, the perspective is the same, but the house is smaller in the 50mm picture, but if you blow it up, it does look the same as the 50.

 

As I recall, the reason the 90mm lens was developed (or other portrait lenses) was not necessarily to take pictures from far away for secrecy and discreteness. It was because you could take a portrait of a person with a 50mm from 12 feet to get a nice perspective, but the film emulsions were not good enough to allow you to blow up the image enough to have, for example, an 8x10 with mainly just the face. You can effectively crop a portrait from a shot with sharp film with a 50 if you are at the right portrait distance although you will have to have shot very wide open to get shallow depth of field as from a 90.

[kelly_flanigan1]

In the old days one wanted a persons head to be at least the size of a dime on the negative, to do retouching. Its way easier if one has an head the size of a quarter, 50cent piece, or the big giant dollars. With distance to the subject as the SOLE control of perspective, one uses longer lenses with MF roll film and 4x5 than dinky 35mm. Thus one migh be using a 180mm on MF or a 210 to 300 on 4x5, or a 50mm on a pentax A110.

[fernando monreal]

I Have not read all the answers, just to said, the depth of field chart of any lens change just a little due to the different confusion circle with the crop factor, but it is practically unapreciable. So you can work with any DOF chart that you allready have for your lens.

f.

[fernando monreal]

Sorry Jorge, forget my answer, better take a look to the Seth Honeyman Link.

f.

[vincenzo_maielli]

Hi, Jorge. The M8 crop factor of the only angle field (not for the focal lenght) is 1,3x.

Ciao.