Schneider Apo Digitar 24mm 5.6 XL with centre filter with the CFV 100C

[caminada]

Has anyone tried the Schneider Apo Digitar 24mm 5.6 XL with centre filter with the CFV 100C?

I'm looking for something wide to use with the Cambo Actus and have heard some reports of issues with the schneiders.

Also.. is the centre filter necessary or is it poss to use this lens and making adjustments in LR or Phocus?

Your responses greatly received.

 

[Paul Spinnler]

THE CF is necessary with the 24 XL. It is a great lens and should cover the crop sensor with some slight vignetting, but limited shift.

@4x5Australian did some tests and can opine on it maybe.

The problem with the CFV 100c right now is that for SK glass and some Rodie wide-angles too you will have ugly banding artifacts in the raws due to the PDAF array.

As of now this is not resolved and everyone awaits the feedback of Hasselblad on it.

 

[caminada]

THE CF is necessary with the 24 XL. It is a great lens and should cover the crop sensor with some slight vignetting, but limited shift.

@4x5Australian did some tests and can opine on it maybe.

The problem with the CFV 100c right now is that for SK glass and some Rodie wide-angles too you will have ugly banding artifacts in the raws due to the PDAF array.

As of now this is not resolved and everyone awaits the feedback of Hasselblad on it.

Thanks Paul. I'll have a look at what else has been posted and I've heard from other sources that there are some issues with artifacts.

 

[Paul Spinnler]

You might also ask @ruebe who recently got a Hassy back and is selling his 24 XL here on the forum. He doesn't have a CF, 4x5Australian has one though.

 

[diggles]

Has anyone tried the Schneider Apo Digitar 24mm 5.6 XL with centre filter with the CFV 100C?

I'm looking for something wide to use with the Cambo Actus and have heard some reports of issues with the schneiders.

Also.. is the centre filter necessary or is it poss to use this lens and making adjustments in LR or Phocus?

Your responses greatly received.

The 24XL/100C RAW files I've seen were made without the CF– one with 0mm shift and another with 5mm of camera fall. The vignetting wasn't that bad and after running the LCC correction in Phocus and exporting the file as a 16 bit tiff, it was fixable with ACR/Lightroom.

Even though there was sky in the upper portion of the images, the streaks were not noticeable in the final file. However, they were noticeable in the LCC frame. The reason could be that the sky was overcast, I'm not sure. Either way, the streaks in the LCC frame did not look any worse than streaks I've seen in LCC files from the 35XL.

My conclusion is that the 24XL is useful with the 100C back.

 

[Steve Hendrix]

BTW - if you're looking for a center filter for the 24mm, PM me, I think we have one or two.


Steve Hendrix/CI

 

[4x5Australian]

Yes, I recently made my first few test frames with my SK Apo-Digitar 24XL using my Cambo WRS 1200 and IQ4-150 digital back. The IQ4 has the larger 53.4 x 40mm sensor.

The lens image circle diameter is stated as 60mm and was not designed to cover the sensor's 66.7mm diagonal, but nonetheless I was interested in seeing what the lens could do for me in tight one-shot situations.

The subject was a five-storey apartment building with panels of contrasty brickwork and textured concrete. I shot the test frames at f/8 and f/11 with the 2-stop SK centre filter IId attached.

While focusing using the live view at 100%, I was pleasantly surprised at the degree of sharpness that I was seeing across the frame.

Initially I shot with zero rear shift, then shifted the IQ4 downwards 5mm to bring the top of the building into the frame.

The images are sharp to reasonably sharp across the field at both f/8 and f/11. The softening towards the edges is only slight and would probably sharpen up easily.

In the -5mm shifted frame, even the additional image that entered the top of the frame is readily usable.

The corner cut-off has a sharp edge, which suggests that the vignette is due to the CF IId rather than the lens. The combination was never intended to cover a 53.4 x 40mm sensor. In my next tests I will try shooting without it.

In my opinion, reports of poor imaging performance from Schneider symmetrical wide lenses (such as the 24XL, 28XL and 35XL) are most likely due to Copal 0 shutters deviating from their depth specification of 20mm +/-0.025 mm. The FFD of the SK 24XL (in Copal 0) is only 26.1mm, much shorter than the 44.8mm of the retrofocus Rodenstock Digaron-S 23mm.

Rod

 

[caminada]

You might also ask @ruebe who recently got a Hassy back and is selling his 24 XL here on the forum. He doesn't have a CF, 4x5Australian has one though.

Thanks Paul. I'll have a look.

 

[caminada]

The 24XL/100C RAW files I've seen were made without the CF– one with 0mm shift and another with 5mm of camera fall. The vignetting wasn't that bad and after running the LCC correction in Phocus and exporting the file as a 16 bit tiff, it was fixable with ACR/Lightroom.

Even though there was sky in the upper portion of the images, the streaks were not noticeable in the final file. However, they were noticeable in the LCC frame. The reason could be that the sky was overcast, I'm not sure. Either way, the streaks in the LCC frame did not look any worse than streaks I've seen in LCC files from the 35XL.

My conclusion is that the 24XL is useful with the 100C back.

Thanks Diggles. That's helpful. Do you remember where the images were posted? Would be good to have a look.

 

[caminada]

Yes, I recently made my first few test frames with my SK Apo-Digitar 24XL using my Cambo WRS 1200 and IQ4-150 digital back. The IQ4 has the larger 53.4 x 40mm sensor.

The lens image circle diameter is stated as 60mm and was not designed to cover the sensor's 66.7mm diagonal, but nonetheless I was interested in seeing what the lens could do for me in tight one-shot situations.

The subject was a five-storey apartment building with panels of contrasty brickwork and textured concrete. I shot the test frames at f/8 and f/11 with the 2-stop SK centre filter IId attached.

While focusing using the live view at 100%, I was pleasantly surprised at the degree of sharpness that I was seeing across the frame.

Initially I shot with zero rear shift, then shifted the IQ4 downwards 5mm to bring the top of the building into the frame.

The images are sharp to reasonably sharp across the field at both f/8 and f/11. The softening towards the edges is only slight and would probably sharpen up easily.

In the -5mm shifted frame, even the additional image that entered the top of the frame is readily usable.

The corner cut-off has a sharp edge, which suggests that the vignette is due to the CF IId rather than the lens. The combination was never intended to cover a 53.4 x 40mm sensor. In my next tests I will try shooting without it.

In my opinion, reports of poor imaging performance from Schneider symmetrical wide lenses (such as the 24XL, 28XL and 35XL) are most likely due to Copal 0 shutters deviating from their depth specification of 20mm +/-0.025 mm. The FFD of the SK 24XL (in Copal 0) is only 26.1mm, much shorter than the 44.8mm of the retrofocus Rodenstock Digaron-S 23mm.

Rod

That's a really helpful review. Thank you for taking the time to respond.

There are a few things here to get my head around. The issue with having a shutter fitted, I'm guessing, is not necessarily a case of just removing the shutter. I would be interested to hear if that is an option for a lens that may be affected by the shutter depth. The one lens I had with a Copal shutter (because it was unsharp!) and never thought of trying it without the shutter.

The critical depths of the lens components do worry me a little in that it appears to have an affect on the quality so readily.

 

[caminada]

THE CF is necessary with the 24 XL. It is a great lens and should cover the crop sensor with some slight vignetting, but limited shift.

@4x5Australian did some tests and can opine on it maybe.

The problem with the CFV 100c right now is that for SK glass and some Rodie wide-angles too you will have ugly banding artifacts in the raws due to the PDAF array.

As of now this is not resolved and everyone awaits the feedback of Hasselblad on it.

Does anyone have examples of the artifacts? I would be interested to see what these look like.

 

[Paul Spinnler]

It’s in the Hasselblad back and 35 XL thread posted by Diggles

 

[4x5Australian]

That's a really helpful review. Thank you for taking the time to respond.

There are a few things here to get my head around. The issue with having a shutter fitted, I'm guessing, is not necessarily a case of just removing the shutter. I would be interested to hear if that is an option for a lens that may be affected by the shutter depth. The one lens I had with a Copal shutter (because it was unsharp!) and never thought of trying it without the shutter.

The critical depths of the lens components do worry me a little in that it appears to have an affect on the quality so readily.

You're welcome.

If the imaging is not up to expectation, try unscrewing either the front or rear cell - slightly - in a few increments of one-quarter turns. Doing so will increase the distance between the two cells. If you find the images improved, great; now find a shim or two to fill that gap permanently. But if the Copal 0 shutter is already too thick the only solution is to replace it with another.

Rod

 

[4x5Australian]

Further to my comments above, here are snips of a few of the test images after applying the LCCs but with no other adjustments.

The first two snips show the full frames at 0mm and -5mm shift, the remainder show detail areas at 100%.

Of those 100% views, the first four are from the unshifted frame and the last three are from the top of the -5mm frame, as per the file labels.

Rod

EDIT:

P.S. The snips reproduced below are markedly less sharp than the original files.

 

[caminada]

That’s really helpful Rod. I’ll have a close look at the shots. Also the suggestion of adjusting the elements to find the sweet spot seems very straight forward.

Alex.

 

[caminada]

Further to my comments above, here are snips of a few of the test images after applying the LCCs but with no other adjustments.

The first two snips show the full frames at 0mm and -5mm shift, the remainder show detail areas at 100%.

Of those 100% views, the first four are from the unshifted frame and the last three are from the top of the -5mm frame, as per the file labels.

Rod

EDIT:

P.S. The snips reproduced below are markedly less sharp than the original files.



View attachment 212112View attachment 212113View attachment 212114View attachment 212115View attachment 212116View attachment 212117View attachment 212118View attachment 212119View attachment 212120

I note the difference between the shiften/non shifted versions and it's not disastrous by any means. Difficult to judge without some other reference to see how well it compares. None the less, very helpful to see these. Thanks for taking the time to post them. Much appreciated. Alex.

 

[Paul Spinnler]

I am not sure that it was noted, but the samples above are with CF. It is an excellent rectilinear SK for crop MF if there aren't banding artifacts in play.

 

[diggles]

Igor Camera has had a 24XL in an Arca R-Mount for sale for a while. Rod’s results looked promising, and with the smaller sensor on the CFV compared to the IQ4, I thought it was worth a try. There are challenges, though—LCC is necessary, and the Center Filter helps a lot.

In the following images the sky had significant vignetting even after running the LCC, and banding is present, so I had to do some cleanup in Photoshop. Despite the issues, I find this lens is a viable option when you want a lens this wide for a tech cam.

This image was shot at f/16 with about 5mm of camera fall…
ENT Center for the Arts at UCCS by Warren Diggles, on Flickr

This image was shot at f/16 with about 7.5 of camera fall…
ENT Center for the Arts at UCCS by Warren Diggles, on Flickr

This image was shot at f/16 with about 2.5 of camera rise…
ENT Center for the Arts at UCCS by Warren Diggles, on Flickr

 

[diggles]

After uploading the images to Flickr I am noticing some banding in the blue sky. This is not noticeable on the original files. It must be happening when uploading to Flickr.

 

[AndereObjektiv]

After uploading the images to Flickr I am noticing some banding in the blue sky. This is not noticeable on the original files. It must be happening when uploading to Flickr.

It's likely 8 bit banding, not a result from the lens/ sensor combination. Flickr allows 16bit PNG as uploads and will only convert the internal-to-flickr file to jpeg, the direct link will remain the full 16 bit png.

For a 24mm that's crazy sharp.