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Rodenstock 40hr strange flare?

jotloob

Subscriber Member
A very interesting explanation . Thank you Paul .
I have both lenses , the 28mm and the 40mm but never saw that phenomena .
My understanding is , that you will not see that penumbra when the light comes from the side or from behind the camera . ? ? ?
Also , I think that the issue will be less obvious when using a smaller sensor like with my CFV-39 and CFV-50 . The sensor size here is 37x49 mm only .
I never shift more than 5mm with the 28mm lens either way and 15mm with the 40mm .
 

Paul2660

Well-known member
Jurgen: (can't figure out how to type the u to show the accent)

I first saw it on the 28mm, with shifts over 5mm, sun at my back, and my reaction was similar to the OP's, "what the *@%* is that" as it ruins the image.

I use the CF on the 28mm, and as I recall, the CF on shifts may make this effect even a bit worse.

I am like you, on the 28mm, I never take it past 5mm, if I have sky pure blue, but will go to 7mm if the scene has non sky or sky with clouds as the lens will definitively make it resolution wise.

I have shifted my 40mm in a test all the way to 18mm and I don't remember getting the penumbra, but for sure hit the disc in the upper and lower corners.

The problem with the disc, is that it creates a void, almost a reversal which is just as had to correct. In the image's from the OP I though at first the dark edge was the disc, but looking back, there is image detail behind the dark vignette, so not sure what is going on optically. However the light band, is identical to the penumbra effect I get with the 28mm as it's shifted too far past the edge of the IC.

Paul
 

Pemihan

Well-known member
Paul, thank you for the detailed explanation.

What bugs me is that the first image I posted in the thread is only with some rise and no shift.
Another thing, shouldn't the corner of the image be solid black if I was hitting the disc and not "only" a black band as seen in the LCC shot?

None of the images has been beyond 10mm shift which shouldn't be a problem but of course combined with rise/fall problems could arise.
And also I have shot many more images with 10mm shifts and maybe some rise/fall with no problems showing.

One thing I have noticed is that the issue is more dominant on the left side of the images. Could be a coincidence or it could point towards something being out of whack in the lens.

Another peculiar thing, the three LCC's below are shot with about 4-5mm fall and are with no shift, 10mm left and 10mm right. Notice how the issue is visible in the no shift and 10mm left image but not at all in the 10mm right image. Also it's only visible in the LCC shots and not in the actual image...! Very weird....

No shift


10mm left


10mm right


10mm left comparing actual image and corresponding LCC
 
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Paul2660

Well-known member
I am pretty certain about the penumbra but I agree I don't understand why after the dark appears it's not all dark.

I am curious what you see with just 15mm of shift no rise or fall. If you see any of the white band or not.


I would also try shifting right and left to see if you hit the disc at the same amount of mm of shift. If something is out of alignment this might show if the disc shows up sooner on one side than the other.

Paul
 

Paul2660

Well-known member
Pemiham:

Just sent you a PM, might also be a light leak. What type of camera are you using? Tech or a camera with a bellows/lens board.

Your right shift LCC looks like it should and it's the same amount of shift. The Left side may have a light leak causing the effect, especially since the image is OK and the effect is showing up only on the LCC, not in the image.

When I hit the penumbra on my 28mm, most times I can see it also on the image especially against a blue sky.

Paul
 

Pemihan

Well-known member
Paul,

Just replied your PM.

I'm using a Cambo WRS with the Cambo compendium which has the same gap for filters as what you're explaining. The lens is mounted in Cambo's Tilt/Swing board.

I was leaning towards the issue being caused by light hitting the front of the hole in the compendium where the lens is shooting through. Since I use the filter slot for the LCC plate the hole is in front of the lens and as such light hitting the edge of the hole might being reflected into the lens causing the issue. (hope this makes sense)

One thing that leads me away from this conclusion is that after going through all my images I can say that the issue is only present on the left side of the images and almost exclusively when shifting 10 mm left. In a few images where I have used rather big rise or fall the issue is also visible with no shift as shown in the first image in the thread.
Also it is more or less visible in all shots shifted 10mm left.
That leads me to think something is wrong with lens.

Also I have used the compendium under the same circumstances with SK60XL, SK120 Aspheric and previously SK35XL and SK47XL with no issues. Only the Rodenstock is showing it.

Peter
 

Ken_R

New member
I have the 40mm HR (Arca R) and use it on my RM3Di with my IQ160 a lot and have never seen this. I use a LOT of rise/fall with back horizontal and vertical and have not seen this. The image is excellent almost all the way to the edge of the disk.
 

LonnaTucker

Member
I have the 40mm HR (Arca R) and use it on my RM3Di with my IQ160 a lot and have never seen this. I use a LOT of rise/fall with back horizontal and vertical and have not seen this. The image is excellent almost all the way to the edge of the disk.
Same for me and I have used my 40 HR with the Aptus II 80 back without ever seeing this problem. I've shifted left and right with an additional rise movement for stitching purposes until the hard disk shows up, but never seen the other bands you are dealing with.

You may need to send both your body and lens to Cambo to be checked out. At least send them a few files to start a support case.
 

jotloob

Subscriber Member
I can hardly believe , that this is caused by straylight from the filter slots .
I never ever experienced something like this , when using the LEE bellows hood with filter slots . And the light would come both sides .

To me , it looks like a symetrie issue in the lens as total unit .
( lens , lens mount , shutter etc.) .:banghead:
 

tjv

Active member
Have you shot a boring "brick wall test" at wider aperture to try ascertain if there is any funky stuff happening on one side or the other? I guess if an element or group of elements were slightly out of alignment you would see that quite easily when using wide apertures, but it would be somewhat covered up at f11 and smaller?
 

Pemihan

Well-known member
Thanks guys,

I have not shot a "brick wall test" but will do some testing Monday morning before sending the lens back to Cambo.

I got the lens less than two months ago so it is fully under warranty. My recent trip to Arizona two weeks ago is the first time I really put it through it's paces and I'm really disapointed to find this issue on all images from the lens where I have been using left shift.

I usually either take a pretty much centered image, maybe with a little rise or fall or I do three images for 16:9 panos; 10mm left, straight on and 10mm right , maybe with a little rise/fall as well.
Pretty much all centered images are fine except in a few instances using a lot of rise/fall, but all images shifted 10mm left shows the issue to some degree, none of the 10mm right shifted images shows it.
 

tjv

Active member
Sounds like it's an issue with your lens only. As far as I can tell the 40mm is an amazing lens, although prone to some flare if not used with a hood. Not flare like this, however!
Good luck!
 

etrump

Well-known member
Peter, You have either a light leak or a defective lens. This is not lens flare and with or without CF you should not be seeing this. What does your dealer say?
 

jotloob

Subscriber Member
Peter, You have either a light leak or a defective lens. This is not lens flare and with or without CF you should not be seeing this. What does your dealer say?

How could you have a light leak with a CAMBO WRS ? ? ?
Unless your lens is not properly mounted , which would be very unlikely .
 

dchew

Well-known member
Not sure this is still needed, but here is a photo of the front of a 40hr. This is with the aperture ring all the way open past f/4. Aperture blades appear just behind that last center ring when you stop down:

 

Pemihan

Well-known member
Thanks for the photo Dave and thanks for your input everybody.

I have been looking through all of my photos shot on the trip and the issue is present on ALL images shot using the Rodie 40 with left shift and in some of the centered shots when using a bigger amount of rise/fall. On ALL right shifted shots everything seems normal.

On the trip I also shot a lot with the SK60XL and SK120 Aspheric and there's absolutely no issues on images shot with those two lenses.

So the only logical conclusion I can come to is that something is wrong with the lens and I will send it back to Cambo first thing Monday as I really need the issue resolved and a working lens back by June 13 at the latest.

By the way, the lens has a slight play in the helical focusing mount or between the mount and the T/S unit. Don't know if that indicates anything but it's there.. Anyway, I'm confident that Cambo will get it sorted out, my experience with their service is excellent.

Thank you again everybody, I will keep you updated..
 

goesbang

Member
The more I think about it, the more I suspect you have an element or lens group out of centre.
Keen to hear what Rodenstock have to say about it.
 
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