Phase One 28mm D & gel filters

[GrahamWelland]

Has anyone used rear gel filters with the Phamiya 28D?

I'm looking to use some significant ND filtering (10-15 stops) with this lens but the Phase One guide that came with my lens offers no instructions about how to best use gels. I know that it'll be a real pain to have to fit/remove the gels and lens between compositions.

I REALLY don't want to screw up mounting and have a mirror accident! Any advice on using it?

 

[Jack]

Graham,

It's been a few years, but inside the paperwork packet that came with the 28 there should have been a little plastic (or maybe it was metal) cutout frame. You use that to wrap over the gel material and trim to its edges, then that will fit in the rear slot. I used it a few times and it was a PITA but worked.

I seem to recall thinking at the time it would be easier to tape a big enough filter over the front of the lens and shade it against flare.

Final option -- have you considered renting a 28 for your Cambo for this project?

 

[Don Libby]

Graham,

I had a love hate relationship with that lens. I loved using it (with my P30+) several years ago and got some great images. I also hated the general design of the filter placement and tried all sorts of things to mount on the front. There's a very old thread on LL that I started before Getdpi was born (or was it before I joined) that covers the trials and tribulations of finding a suitable filter solution of the lens.

Bottom line was that there wasn't a final solution for a front element filter which left the gel in the rear. Back then I couldn't find an acceptable method of mounting the gel and gave up on the idea all together. Not too sure what I'd do today if I were using it.

I may have missed this - how well does the 28 work with full frame backs? I know it worked well for the P30+ I had and remember only testing it a little on the P45+.


Don

 

[Craig Stocks]

Has anyone set uo a matte box solution for filters on the Mamiya 28? I did something like that for a 14mm Canon and it worked OK.

 

[GrahamWelland]

Graham,

It's been a few years, but inside the paperwork packet that came with the 28 there should have been a little plastic (or maybe it was metal) cutout frame. You use that to wrap over the gel material and trim to its edges, then that will fit in the rear slot. I used it a few times and it was a PITA but worked.

I seem to recall thinking at the time it would be easier to tape a big enough filter over the front of the lens and shade it against flare.

Final option -- have you considered renting a 28 for your Cambo for this project?

Thanks Jack,

I found the metal frame that you mentioned in the box and I figured that it was a case of trimming filter gel for it. The lack of any instructions about using it concerned me enough to ask because the last thing I want to do is not fit it correctly and have it come loose in the mirror box as I'm sure you'd understand. All other rear gel solutions I've used in the past have had a well defined slot for a gel to slide in to or had filters that screwed/dropped in.

Regarding renting a lens - well that would be for the Alpa and I'm shooting with the P25+ vs my IQ160 as it is for exposures several minutes long. I certainly could do it and actually go even wider in that case with a 24 XL (which ironically I used to own but sold when I went with the IQ160).

Graham,

I had a love hate relationship with that lens. I loved using it (with my P30+) several years ago and got some great images. I also hated the general design of the filter placement and tried all sorts of things to mount on the front. There's a very old thread on LL that I started before Getdpi was born (or was it before I joined) that covers the trials and tribulations of finding a suitable filter solution of the lens.

Bottom line was that there wasn't a final solution for a front element filter which left the gel in the rear. Back then I couldn't find an acceptable method of mounting the gel and gave up on the idea all together. Not too sure what I'd do today if I were using it.

I may have missed this - how well does the 28 work with full frame backs? I know it worked well for the P30+ I had and remember only testing it a little on the P45+.


Don

Thanks Don,

I had actually found your LuLa thread about this. I seem to recall even that someone had also adapted the Lee filter solution for the Nikon 14-24 for use with the 28D as well. All the 'solutions' I saw left the side of the petal open which for me would be unusable due to light leak. For a polarizer or grads it certainly could work though.

As regards the corners on full frame, to be honest they're not great and I've typically been able to shoot wider with the IQ160 and crop in slightly where necessary. With my P25+, which is the back I mostly use on my DF, there is basically no problem at all just as you've experienced with the P45+. I prefer the look of the 28D to that of the 35D so I'll actually shoot the 28 and crop vs using full frame on the 35D where the corners go to mush even sooner.

 

[coulombic]

I actually shaved the metal hood off the front of my 28D some time ago, and then glued (metallic epoxy) a metal ring around the front-edge of the lens as to adapt the P-Zero filter holer. Worked pretty well, honestly -- I even used a Lee Big Stopper with it with no light leaks. I see it as a completely viable solution for an otherwise irritating problem.

Unfortunately, on a full-frame back, the lens is infuriatingly bad in the corners. To get any sharpness at all in the corners, extremely small apertures like f/19 must be used, and even then, it's not great. Thus, any image taken with the lens that was "tightly" composed really never worked out for me, due to the tremendous amount of cropping needed in light of the poor edge performance on a full frame.

I'd happily take pictures of my setup, but I actually do not have the lens with me (and likely won't have access to it for months).

 

[Don Libby]

Actually every filter design I came up with sucked as I kept getting various degrees of vignetting and that was with the P30+. I completely gave up any hope of finding a suitable solution after spending a couple hundred. This was very close to the time I made the move to a tech cam and thinking back now I have to question if that wasn't one of the reasons.

 

[GrahamWelland]

I actually shaved the metal hood off the front of my 28D some time ago, and then glued (metallic epoxy) a metal ring around the front-edge of the lens as to adapt the P-Zero filter holer. Worked pretty well, honestly -- I even used a Lee Big Stopper with it with no light leaks. I see it as a completely viable solution for an otherwise irritating problem.

Thud!!! (that was the sound of me fainting .... )

I can actually understand the logic behind this although a bit too extreme for me. It's actually big stopper shooting that I'm doing a lot of these days stacked with grads too but obviously only on the 35D and longer due to the lack of mounting solution.

I'm considering getting some of the Kodak ND gels and cutting them down to fit on the rear filter holder. For daylight shooting I may have to use a couple of gels to get 13+ stops that I'm looking for and hopefully without the images looking like crap - I haven't tried stacking filters behind the lens before so I don't know if this'll work well or whether there will be horrible effects like newton rings etc.

Unfortunately, on a full-frame back, the lens is infuriatingly bad in the corners. To get any sharpness at all in the corners, extremely small apertures like f/19 must be used, and even then, it's not great. Thus, any image taken with the lens that was "tightly" composed really never worked out for me, due to the tremendous amount of cropping needed in light of the poor edge performance on a full frame.

I'd happily take pictures of my setup, but I actually do not have the lens with me (and likely won't have access to it for months).

Agree about the 28mm performance in the corners. I so wish Schneider would tackle the wide end of the Phase One system!! For my uses though I'm not overly affected by the lens effects as its the big vista that I'm usually shooting or I can vignette the corners if need be in shots that go to mush in the foreground (or what I normally do is crop if using FF sensor).

Would love to see your modified lens at some point. If there was a way to get someone like SK Grimes to make an adapter or replacement for the hood assembly thenid consider that vs breaking out the dremel (which would never happen).

 

[Don Libby]

I actually shaved the metal hood off the front of my 28D some time ago, and then glued (metallic epoxy) a metal ring around the front-edge of the lens as to adapt the P-Zero filter holer.

I came very close to do that however did have the cajones.

Don

 

[GrahamWelland]

I'm attending a Vancouver Photo Workshop Long Exposure shooting event this weekend with Marc Koegel. What has been interesting has been diagnosing the various light leaks in the DF & IQ160 mount. Let's just say that if you're exposing for 1-2 mins in daylight that you'll need a roll of gaffer/camera tape because there's one heck of a light leak around the edge of the back on the body that you'll likely never see unless shooting under these extremes. I'll post some pictures of the effect later. Just suffice to say that if you're pushing the exposure timing then you'll want to tape the top corners of the back/body in addition to the normal VF light mask.

 

[jotloob]

. . . . . Let's just say that if you're exposing for 1-2 mins in daylight that you'll need a roll of gaffer/camera tape because there's one heck of a light leak around the edge of the back on the body that you'll likely never see unless shooting under these extremes. I'll post some pictures of the effect later. Just suffice to say that if you're pushing the exposure timing then you'll want to tape the top corners of the back/body in addition to the normal VF light mask.

Graham

I have a dark cloth , smaller than the one I used for my 4x5 inch camera .
It is black inside and has a silver/metal coating on the outside .
I have that cloth always with me when I am shooting with the ALPA .
It is very useful when using the GG for composition (as well as the little ALPA leather thing) and also when I use the iPHONE viewer under extreme light conditions .
But the cloth could also be used for your "light leak issue" .
If it is too big , you can always get it made smaller and have additional vecro-fasteners . So it would be like a kind of nappy around your camera and back .

 

[Paul2660]

Graham,

How well did you 160 do at the 2" exposure? That's well past the limit that Phase One states, so I am very interested, noise, banding etc. I am also curious as to your light leak, as I think I may be getting these with my Arca mount on the IQ160, but only on shifts and only when the exposure is about 20 seconds. In my case it didn't ruin the exposure, but sure added some anxiety.

Paul

 

[GrahamWelland]

Paul,

Actually I'm pretty surprised at how well the images work. There's definitely noise but I noticed that the folks in Denmark are definitely covering our back because C1 Pro automatically seems to apply a different set of default noise parameters to long exposure shots. I was scratching my head at first wondering why I'd changed the defaults from Luminance/Color/Pixel from 25/34/0 to 25/52/50 but then upon further investigation it was C1 setting it.

Is it perfect? No. Are there hot pixels - definitely. Does it matter when converting to B&W for silky long exposure shots? Nope. Marc Koegel recently had to change to an IQ140 after the death of his P45+ and he's been shooting at 4 mins+ too. Now it definitely is a trade off and the heat soak adds up I noticed but depending upon the image I think it's very acceptable.

Once I'm home (or at least got a working hotel internet) I'll upload some samples. The biggest issue by far though is the horrible red light leak/reflection. I'm shooting today with my Alpa to see how that fares. Right now I'd definitely recommend overing the back/camera body with a hat (a beanie seems to work). I thought I'd figured out the major light leak but more tape is required ...

 

[GrahamWelland]

Juergen,

Yes I think I'll be breaking out my Harrison cloth too. Time to stick some velcro to the bodies!

 

[GrahamWelland]

These were my test shots - so by no means high art.
Daylight - 2 min exposure bright sun. Horrible light leak:

Basic B&W Rendering from C1:

Using a beanie hat to cover everything:

Just taping the top edges of the body/back - not quite nailed it yet:

 

[Paul2660]

That is good news. In my usage, on the longer exposures, I see the stuck or hot pixels on the LCD, but when I open them in Capture One, most get mapped out. I assume this is done during the dark frame capture in the back as it was with the P45+. On the longer exposures, the darker areas seem to look very blotchy when viewed on the LCD, but seem fine later on.

I wonder what happened to his P45+, I thought they never died! I regretted trading mine in at the time, but now looking back at the images from 160, I really prefer the look/feel of them over the P45+. I had also quit using the P45+ for night work since I mainly stack now and stacking with the P45+ was never a good solution mainly due to the file sizes. I did get some great 50 minute shots with it though. With the demise of Kodak I have wondered how long the P45+ could still be manufactured. I had hoped to pick up a used one in a year or so.

Glad to see you are getting good results.

Paul

 

[GrahamWelland]

Yes you definitely see a mass of red blue and black pixels on the LCD when you zoom in. The raw converter/dark frame seems to clean things up when you get it in C1 though. Shadows ... not pretty but that's to be expected really.

 

[Landscapelover]

I've never tried Mamiya 28 mm with Lee Big Stopper (10 stop). I've never had luck of this lens with any filters. Hasselblad HCD 28mm with Cokins is much better for long exposure.
However, I've been successful with Mamiya 35mm AF (mine has a broken AF and cost me only $175) and SK 55mm with GND or Polarizing filter and Lee Big Stopper for 60 sec. My camera is P1 DF and IQ180.
This picture was taken with 35mm, Lee Big Stopper and GND (I think) at 60 sec. I shaded the sun with my hand.
Pramote