Hood for Canon 25/3.5?

[kermaier]

Was there an original hood for the Canon 25/3.5 lens? Does anyone know what would be a usable modern hood that doesn't vignette on the lens?

 

[xayraa33]

I never found one for my 25mm.
just a Canon thin UV filter is all I use and I do not find this lens to be really flare prone.

 

[laptoprob]

No hood needed. Although,on my R-D1 I use the 12585 Leica Hood to minimise flaring. But I think the flaring of this lens on the R-D1 may be caused by sensor reflection. As soon as I have the camera back I will test if removing the rear flat piece of glass makes a difference.

 

[kermaier]

No hood needed. Although,on my R-D1 I use the 12585 Leica Hood to minimise flaring. But I think the flaring of this lens on the R-D1 may be caused by sensor reflection. As soon as I have the camera back I will test if removing the rear flat piece of glass makes a difference.

How are you able to mount the 12585 on a Canon 25/3.5?
Are you joking about removing the rear lens element to see if it reduces flare???

 

[laptoprob]

I can mount the hood on the UV filter rim. I only take the filter off in very low light, to avoid ghosting. No, I am not kidding about the rear glass test. It is simply screwed on and it may just add to sensor flare. I don't think the 'float' glass adds anything optically except protection. Any defect on the rear lens will definetely affect the image.

 

[CanonRFinder]

Canon never made a hood for the 25mm f/3.5 lens as the front element was set so far back into the body of the lens. Peter

 

[kermaier]

Thanks for the replies. I guess the flare I sometimes see results from bright light sources in the frame, where a hood wouldn't really help.

You're right CanonRFinder -- the lens barrel does shade the front element pretty well, like with the Canon 28/35.

 

[John Shriver]

The flat glass is part of the optical design. Not only correction, it won't focus accurately without it.

 

[Sonnar2]

the flat back element is probably for better handling. It makes the lens longer and allows easier focussing and aperture setting.
Compare it with the Nikkor 25/ f4 with the same basical design but misses the flat element

 

[laptoprob]

The flat glass is part of the optical design. Not only correction, it won't focus accurately without it.

But how can a flat piece of glass have an optical function?
Other than protection ofcourse.

 

[John Shriver]

Since the light isn't collimated when going through it, it does have an optical function. It's still bending each wavelength a different amount, so it affects chromatic aberration.