Mamiya TLR lens hood too short?

[cmo]

Today I had the same experience once again: there are reflections shaped like the diaphragm on some of my photos, taken with a Mamiya 330 and a 105mm DS lens, nice backlight landscape shots, ruined by a reflection.

I don't need to tell you that you never see these disturbing reflections in the finder, but only on the film. The TLR surprise...

Strange enough, I do ALWAYS use a lens hood, and the one I used is exactly the hood for the 105mm lens. As I love back-light shots I would like to solve this problem. Using a compendium is not possible because it is not possible to control the effect on a TLR (surplus, it would cover the finder lens).

I guess that somebody else must have similar problems with this lens or others. Avoiding back-light is not an option for me, and I want to keep my Mamiya (Ma Mamiya, you know...)

What did you do to solve the problem?

 

[Ian Grant]

If it's backlit then maybe a lens-hood is only marginally useful anyway. Often with my SLR and a lens hood I have to use something else to shield the strong light getting into the lens & stop the flare.

Some lenses are just more prone to flare than others, my modern 5x4 lenses are remarkably flare free. Older lenses suffer far more badly.

There is one possibility, a way to improve your lens-hood, I had a Hoya lens that flared very easily and made a cardboard piece with an aperture that was effectively like barn doors stopping all light other than needed for the image itself, this made a huge difference.

Ian

 

[Michel Hardy-Vallée]

It's flare, the result of shooting against the light. A lens hood is useful for blocking light that comes from the sides. If you want to block light coming from the front... I'll let you deduce.

Given that you have the DS lens, I suggest you close the viewing lens diaphragm. You might be able to preview flare spots and perhaps avoid situations.

The Mamiya TLR lenses are very good, but their coating is not in the same range as the Zeiss &c.

 

[cmo]

I forgot to say: the sun was OUTSIDE the frame. The hood is made for that, but I doubt it is big enough. I closed the diaphragm to preview the DOF actually, but there was no sign of a flare problem.

 

[2F/2F]

You can't get rid of them. You are shooting right in to the light, so no lens hood will fix the flare. How could it? (A lens cap could do it!) Certain lenses themselves might minimize it, but a hood won't do much if you are shooting right into the light. The best bet in this case would be an assistant shading your lens from afar with a card or a reflector. Also, perhaps the viewing lens has fewer elements than the taking lens, so is less flair prone...I don't know. But I can assure you that the effects of shooting into the light are visible on the ground glass in some way; probably just a low-contrast image on the glass.

 

[Michel Hardy-Vallée]

I forgot to say: the sun was OUTSIDE the frame. The hood is made for that, but I doubt it is big enough. I closed the diaphragm to preview the DOF actually, but there was no sign of a flare problem.

OK, so then you probably want to use a flag of some kind to shield as much light as possible. Find the biggest piece of cardboard you can, and position it to shield the direction of the sun, making sure it does not intrude in the picture frame.

 

[cmo]

OK, so then you probably want to use a flag of some kind to shield as much light as possible. Find the biggest piece of cardboard you can, and position it to shield the direction of the sun, making sure it does not intrude in the picture frame.

How would you control that if you use a TLR? The two lenses are not 100% identical, and I can not see the result of shading the lower lens if I look through the other. That's my TLR problem. I love the concept of the camera, but here it has a flaw and I don't know what I can do to fix it.

I even thought about setting the camera on a tripod, without a film, use a lamp to simulate the sun, place it outside the frame and control the flare on some kind of matte screen I put into the film chamber...and create some kind of extension for the hood, just big enough to prevent the flare. I wonder if somebody else tried that.

 

[2F/2F]

Just move the cardboard until your camera is in the shade. You won't be able to shade it any more than that in all practicality! There is no point in only shading it a little bit.

 

[Ian Grant]

This is where masking the Lens hood is very helpful, essentially you add a square black mask to the front of the lens hood. It's a technique used particularly with cine camera lenses. I have a Kodak 8mm camera and the lens hood crops tight to the format. You'd need to experiment, use black tape see how close you can crop before the tape impacts the image lens wide open & stopped down.

Somewhere on APUG someone has posted a link to a web-page describing how to do this.

Ian

 

[Michel Hardy-Vallée]

How would you control that if you use a TLR? The two lenses are not 100% identical, and I can not see the result of shading the lower lens if I look through the other. That's my TLR problem. I love the concept of the camera, but here it has a flaw and I don't know what I can do to fix it.

I even thought about setting the camera on a tripod, without a film, use a lamp to simulate the sun, place it outside the frame and control the flare on some kind of matte screen I put into the film chamber...and create some kind of extension for the hood, just big enough to prevent the flare. I wonder if somebody else tried that.

Sun is at infinity, so parallax at infinity asymptotically goes towards zero... I don't think you should worry about it. And why would you "simulate the sun with a lamp" instead of doing real-world tests?

Plus you said the sun is on your side. There is no horizontal parallax on a TLR, only vertical. So if your flag's axis is parallel to your lenses' axis, WYSIWYG.

Just try it.

 

[Christiaan Phleger]

The simple solution would be to use a crazy long deep hood.
I usually use a 46-52 step up, then a Nikon HS-1 (for 50mm Ai ) or even an HN-7 (85mm 1.8) for the Mamiya 80mm. I have a very long narrow Nikon HS type hood for the 105mm 2.5/ 135mm 3.5, I'll try that and see if it 'clips the corners'.
Its 2 inches long and 2.75 across, probably Much larger than the stock Mamiya hood.

 

[Christiaan Phleger]

Sorry, that was an HS-9, for a 50mm 1.4 Nikkor.

I did test the longer hood, that looks to be the HS-4, and by the viewing lens on the 80mm, it does not vingette the corners. I'll do an on film test, I have a 'dropped optic' to re-test.
There is also a Hoya square hood option that I plan to investigate as well.

 

[benjiboy]

I use Mamiya TLR's and although I don't have the 105 DS lens, in the situations you describe I shield the lens with my cap.

 

[cmo]

Here I have an example:

http://www.rangefinderforum.com/photopost/showphoto.php?photo=89933&ppuser=816

As you can see the sun is quite high above. These reflections were not visible in the finder, the hood was on the lens. A perfect photo, perfectly ruined...

I know the trick with the cap, but I don't like to carry a tripod to be able to control the effect of such a 'lens hood'.