Recommended E6 chemistry

[Lelo]

New LF user here (actually returning from years ago) and would like to use my DSLR as a lightmeter for shooting with my new Intrepid - for now. I'd like to "calibrate" it first by making sure ISO 100 on the camera corresponds to the ISO of the film, and if it doesn't, make adjustments (for ex, meter at 80 to shoot at 100).

I think the best way to do this is to take test shots on Provia or some other E6 film. Can anyone recommend an E6 kit? I'll be developing in the Stearman 445 tank.

Thanks,

John

[Pere Casals]

Hello John,

I'm using Tetenal Colortec E-6 because 3 bath simplicity, a very good choice is Fuji Hunt.

For E-6 processing a rotary like JOBO CPE-2 is recommended, because you use a very low chem volume per sheet, the 455 tank requires > 100ml per sheet, see Colortec datasheet.

For the metering I'd recommend you first shot some 35mm rolls with any cheap slr like Nikon F80, make bracketings of typical scenes, meter sky, clouds, forest, etc, with the spot meter and write down local over/under exposures in those subjects for the tests. With slides carefully spot metering can be very good because overexposed areas cannot be recovered, and deep shadows may not be easy to scan. You also should test with filters.

In that way you can recall how sky/clouds/etc will result from the spot metering if you recall your tests. This is the way you may nail exposure for your slides.

A Velvia sheet is a treasure, and any related pitfall is really painful.

[Pali K]

You're going to complicate things more going with the E6 route because the processing itself will impact your ISO calculations unless you have a way to keep temps and agitation very consistent. Pere mentioned a JOBO system which will make things much easier.

Are you trying to troubleshoot your shutter for accuracy or the conversion from DSLR metered to Film in general? If it's the shutter, look up shutter tester cell phone apps that do a great job for speeds up to 1/60th.

Since you have past film experience, I am sure you know that negative film is quite forgiving vs slide so my tip would be to start with negatives first.

Good luck and welcome back! I was a boomerang from Film to Digital to Film about 10 years ago and absolutely love being with film primarily now.

Pali

[Lelo]

Thanks for the info, Pere & Pali.

Good idea to do the test with a 35mm camera - cheaper, faster and more complete with 36 exp rather than what I'd settle for with 4x5 before calling it good. I may evolve my darkroom gear over time - or I might send the film out and have it done. Somewhere there is a break-even point for quantity vs. cost and I don't yet know how often I'll be able to use the camera.

I'll probably end up shooting mostly Ektar but if I can nail the exposure with transparency film I'll know I'm spot on, as the Brits say, with the Ektar.

The whole purpose of this is to test the feasibility of using a DSLR as a light meter and I've heard that a digital camera's ISO isn't necessarily what a film's ISO is - that they may not translate into equal values. I wish I could justify an expensive Sekonic spot meter but, it's just not in the cards at this point.

Thanks again for the info and advice.

[Pere Casals]

the feasibility of using a DSLR as a light meter

A DSLR is a perfect LF meter while you use the spot mode. Digital and film have different exposure needs, if you use matricial mode in the DSLR then there is no true rule to match the readings.

Even a "modern" film SLR may use the DX code in the 135 cassette to know the latitude type of the film, thus influencing the metering in matricial mode.

Just mount a prime lens (Nikon 50mm F/1.8D ...) in the DSLR to have a similar light transmission than with a LF lens, and remember that for close shots you should correct exposure depending on bellows extension.

[Havoc]

Looking at the price for Provia and a quick back of the envelope calculation, I'd say that you're likely to spend the cost of a nice lightmeter before you arrive.

[Pere Casals]

Looking at the price for Provia and a quick back of the envelope calculation, I'd say that you're likely to spend the cost of a nice lightmeter before you arrive.

A cheap SLR (Nikon F65) is a perfectly accurate spot meter, of course one may buy a pro meter for a number of reasons, but nothing prevents to nail exposure of slides by metering with a DSLR or SLR.

Most of problems found in metering comes from the spectral sensitivity in light meters, for eaxample it's easy to overexpose the blue layer of slides with a perfectly blue subject, because the blue subject has a low total reflectance delivering a low reading but that reflectance it's very concetrated in the blue, so blue layer is overexposed.

A DSLR allows to take a pre-shot of the scene to see the R-G-B histograms in the back screen, it even allows to use a zoom (cheap/lightweight $50 70-300 G) to take the histograms of small areas, so in fact we have a 3-way RGB meter. Of course it requires a testing job to understand how the R, G, and B sensitive layers of Velvia/Provia behave, but there is no doubt that with a DSLR we have an advanced precission instrument that we can use to nail the exposure of the sheets.

Also a DSLR can be used for incident metering, by just spot metering on a grey card or on concrete, realizing that in some situations incident metering is a very consistent way, clearly not always.

Of course we can meter with a good Sekonic, but (beyond weight) in no way a DSLR is an inferior meter. Today even an smartphone may deliver accurate meterings.

[Havoc]

RGB histogram on most dslrs come from the jpeg, not raw. Also if you want some decent spor metering you'll need at least a small tele like you say. Also consider weight and battery life compared to a dedicated light meter. And you still have no incident metering. And with slides this is what for me works every time (medium format velvia and provia)

[Pere Casals]

RGB histogram on most dslrs come from the jpeg, not raw.

hmm, true, this shuold be checked, but if pre-shot is raw only then histogram information cannot come from a jpeg... well, this is something to check...



Also consider weight and battery life compared to a dedicated light meter.

True, but also you have a digital camera with you.



Also if you want some decent spor metering you'll need at least a small tele like you say.

No, in spot mode a Nikon D3200 has an spot size of the 2.5% of the scene, so you have a true spot meter. The tele would be for having the histogragram of an small area, if wanting that.




And you still have no incident metering.

You have it, just bring a "credit card sized" standard grey card and meter on it.



And with slides this is what for me works every time (medium format velvia and provia)

Depending on what you shot, if in your framing you have sky and clouds the incident metering will not tell what graded filter you need to conserve detail in the clouds.