Blotchy pattern on 4x5 negatives

[Patrick Gauthier]

I think the reason I initially saw the effect on some photos and not others is because the holders were exposed to different amounts of light, and it may be that some of my "clean" negatives actually have minor light pollution that's masked by the details of the image.

yeah that makes sense. I've generally heard good things about the toyo holders, but have only used fidelity elite's myself. I hope the new darkslides work out for you.

Patrick

[Doremus Scudder]

I'm just now checking back on this after a great while. Great work finding the problem! This is worrisome, however, for those with Toyo holders. There may be a lot more out there like this. I'm glad Toyo is responding with new slides. Maybe they will need to do a "recall" of some sort if there is a large number of holders like this.

Question: Can you see light coming through the defective dark slides with your eye when holding them up to the sun or a bright light source and looking through them? It would be good to find a way to test the darkslides on holders one was intending to purchase before paying...

Please keep us updated on the new slides from Toyo and how they plan to deal with this issue.

(This puts a whole new twist on the "Darkslides: new or used" thread...)

Best,

Doremus

[marmot]

Doremus, I can't see sunlight through the dark slides outside, but I can see light from an LED headlamp coming through in a darkened room.

[Willie]

Are Toyo or B&H going to give you a few hundred sheets of film as well?

[plywood]

Now I don't feel bad about only buying old, used Fidelity and Riteway holders. Of course, my 'film' has been limited to photo paper at ISO 3-6 so no real test there. Have had a minor light leak on some holders that had been loaded for 6 months and carelessly left out in room light but even in sunlight they seem to be ok for regular use for paper negatives.

[AtlantaTerry]

I wonder if these problem holders are passing infrared light, not light in the visible portion of the spectrum.

Why would Toyo not now test the dark slides themselves rather than depend on an end user? (No offense.)

[Jordan]

I bought all new darkslides for my Toyo film holders back in September. I have zero confidence in them now after reading this post. I've only made a handful of exposures using them since thankfully. I tried shining a bright flashlight through them in a dark room and couldn't see anything, but still this is such a negligence on their part. As a large format film user I try and use the equipment and materials that allow me to not have to worry about their reliability as this type of work takes time and patience and both of those things as I'm sure you all feel to some extent are precious and not to be wasted on something faulty like brand new darkslides that fail to block all of the light.

[marmot]

So MAC Group got back to me and let me know that Toyo did their own testing and determined that the slides had been milled too thin, hence the translucency. They're going to replace my slides.

[Jim Michael]

I read that as the attenuation increases with thickness but is not 100%, esp. with the limit on the amount that could be added.

[stawastawa]

fascinating, and a bummer.

do old replacement darkslides fit in the toyo holders? There are some available on ebay.

Also, I think someone should start an image thread for all theses 'light leak' / 'mistake' / 'ruined' images. It does cause a neat effect sometimes.