DSLR-wide angles or RF-wide angles?

[LeicaFoReVer]

I read an article in the past and it was saying RF cameras can have simple designs for wide angle lenses due to less lens to film distance which gives way less distortion (any kind) amounts compared to DSLR wide angle lenses. Is that still true or a myth? Did recent technology overcome this problem with complex designs in DSLR lenses?

This was mentioned in a recent thread but it was not discussed enough I believe. Some says Tamrom 17mm gives perfect distortion free images. Some says some Nikon SLR wide angle lenses are distorted.

 

[GusW]

On the wide angle side of the spectrum (D)SLR cameras have never been able to seriously compete with RF designs, as you said, due to the distance between the back element of the lens and the film plane - there being no mirror system.

I have used many different ultra/supper wide angle lenses on reflex cameras (Canon, Nikon, Tamron, Sigma, Tokina, Pentax..). I always shoot quite wide and am in the market now for a Leica M6/M7 precisely because of this reason. Other designs, such as the Hasselblad SWC models (fixed lens camera) also followed this design philosophy.

The distortion problem on super wide angles used on reflex cameras will most affect your images towards the edges, specifically if the subject is close to you. So you can plan your shots accordingly. But to answer your questions - I do not think technology have or can easily erase the gap between reflex and RF wide angle lenses.

Gus

 

[venchka]

The problem applies to any reflex viewing camera arrangement and retrofocus design lenses. If you look at a lens designed for reflex viewing, the flange of the lens and rear element are always the same distance from the film plane. This is required for the moving mirror to clear the lens. Some SLR wide angle lenses use floating or moving elements to improve performance. There are some SLR lenses that seem to overcome all the obstacles and deliver great perfomance. Alas, they cost as much as a good used car.

 

[furcafe]

Doesn't it also depend what you mean by wide angle? My understanding is that the modern aspherical Leica 35mm & 28mm designs are retrofocus, just like the SLR designs.

 

[venchka]

In my experience, 24mm and wider for 35mm and 50mm and wider for medium format are where the problems or big bucks solutions happen. Lenses like the Zeiss 21mm Distagon, Leitz-R 19mm and 15mm offerings, Zeiss 50mm and 40mm Distagons for Hasselblad. Even my humble Canon FD 24mm lens has floating elements.

Interesting about the modern Leica lenses. I have the Konica counterparts. The 28mm M-Hexanon extends 12mm into the camera. Missing the swinging meter cell of the M5 by a silly mm or two.

 

[Nikon Bob]

If you are looking for a wide to super wide angle lens that is free of any and all distortions you are in for a shock. If they exist I could not afford them. There are distortions induced by the shooter not keeping the camera level causing keystoning and it is much easier to get into trouble with a wide this way. There is barrel and pin cushion distortion that is easily corrected for in post processing and not to much of a biggie anymore, at least for me. Then you have the distortion that causes objects near the corners and edges to stretch and little can be done about it except find a lens that has less of that than the one you are using. What I am saying is don't obsess about WA distortion because to a more or less degree it is inherent in the design of WA lenses. Most modern WA designs of both camps, RF and D/SLR, are amazingly good but none are perfect, yet.

Bob

 

[Ronald M]

True some of the RF Leica wides are retros to accomodate the RF metering. But they are not as retro as slr lenses.

Leicas wides for RF bodies are close to distortion free going back to the 3.5 Summaron.
Supposedly my pre asph 21 has some moustache distortion, but I never noticed it. The current 35/50 Summilux and Summicrons have inconsequential distortion if any. 50 1.4 second and third have some distortion. version 1 has none. The version 4 or current is without and is probably the best 50 1.4 I ever used. The old 21 3.4 SA has little if any distortion, but heavy heavy vignetting is the trade off. For my purposed Iconsidered it a F16 lens. I sold it within 3 months and got the new pre asph which I still have.


All I can say is extreme care is taken in Leica`s design to avoid it. They can be used full open if required at some quality loss.

Now come the Nikon wides which i purchased for my D700. 50mm and shorter have significant distortion. The are not as good wide open as Leica RF lenses. I have 15 of them. As a family, they are the same.

Original Leicaflex wides have no distortion so you see it was possible to make them in the same era as my early Nikkors. They are perhaps slightly better correced full open than Nikkors, but no real prizes until you get into the asphs. 35 2.8 with 55mm filters is a winner. But that is a late design. My 35 2.8 Ais Nikkor is comperable, but with more distortion.

Leicas asph, any of them, bring the art of lens design to a new level.

 

[kkdanamatt]

DSLR-wide angles or RF-wide angles?

Short focus wide angles have the rear elements close to the film plane. They can't be used on SLR's because of the mirror. Retrofocus wide angles solve that problem but introduce design problems which are not present with short focus designs.

In my experience, RF wides almost always outperform SLR wides. Now, I must admit I have not yet shot with some of the latest wide glass from Zeiss, Canon and Nikon. I do have the Nikon 20mm and 24mm AF-D lenses, which are excellent; but the 21mm and 25mm C/V lenses are better on the edges, IMHO.

I have shot with the Sigma and Tamron wides and they do not match up well with any of my C/V and Leica lenses. Besides the excess edge distortion there is the excess size and weight factors to consider. They are cheap to buy, however.

Also, if you manually focus a DSLR/SLR camera, the SLR wides are harder to focus accurately because everything looks small and sharp all the time. RF cameras are more accurate because the RF baselength doesn't change and the patch is the patch, regardless of focal length. Of course, autofocus eliminates that problem.

Lastly, the best 28mm bargain is the Contax G lens for the G1/G2. Incredible is only word for it. You can buy a G body and 28mm lens for less than $450.