Enlarger too hot, which filters? (Bessy 67)

JohnMilleker · Dec 18, 2009

Hello everyone, I've recently purchased a Beseler 67sc in beautiful condition but have a question about filters.

I've searched and searched and just can't get solid information to figure out what I need.

Using the recommended bulb (PH140) my Beseler is way too hot, printing on 5x7 RC/Graded #3 paper my exposure time is 3-4 seconds. Certainly too little time for any work that had me seek out to get into enlarging in the first place. I'd much rather get this time to 10-15 seconds.

First of all, I know I need 3 1/2 inch filters for inside the head. I see Ilford variable contrast filters. My question though, should I be looking for an ND filter that will be able to take the heat? What if I start enlarging Variable Contrast papers? Perhaps the way to go is a ND to fit in the filter holder under the lens instead so that I can still use variable filters?

Thank you for any help you can provide! I've been hit by the darkroom bug and I've been really enjoying developing again. Ok, the smell of stop bath and blix is certainly wonderful too.

-John

alkos · Dec 18, 2009

Increase the aperture one stop for 6-8s, two stops for 12-16.

JohnMilleker · Dec 18, 2009

Is that all I can hope for Alkos? I'm already at 11 and really a fanatic about sticking at f/8-f/11 for the sweet spot, I'll give it a go at 16 and see what I can make of it. I haven't really had a care about using vari contrast papers so the Ilford filters may be the way to go..

Thanks for the help!
-John

alkos · Dec 18, 2009

I am not familiar with your enlarger design, but I've successfully used a ND filter over my focomat's condensor...

ic-racer · Dec 18, 2009

1) The popular multicontrast filter sets have some ND built in to even the exposures, so if you go this route your times will be a little longer.
2) If your times are still too short, an acetate ND filter should be relatively inexpensive and should be able to be placed on top or below the multigrade filter. Every 0.3 units of the ND filter grade will double your exposure.

John Koehrer · Dec 18, 2009

I'm guessing you're using a 50mm lens. You can also increase exposure times by using a longer lens(80/90/100mm)and also have more room between the head & base board to burn & dodge.

fotch · Dec 18, 2009

Could the negative be on the thin side?

JohnMilleker · Dec 18, 2009

Thank you all. IC, Great calculation on the exposure time. Though there goes the possibility of using my 2,4,8 stop ND Cokin filters in a pinch. I'll start with the contrast filters first, they're pretty cheap on eBay and it might be something to have if I ever start shooting variable papers. Stranger things have happened.. When I started shooting film again I never wanted to enlarge but here I am.

John. That's going way out of comfort territory for me, though as I progress to MF and large format negs, I know I need those anyway. I'll give those a try, can never have too many excuses to buy new lenses!

Fotch, yes and no. The first shot at 5 seconds may have been a thin neg now that I think of it, but the other one wasn't. The other shot was exposed at 2 1/2 seconds but was a higher-key shot anyway. I will admit that I've been scanning and getting spoiled by Photoshop. I may have let the quality of my negatives slide a bit, but nothing that's way over or under exposed/developed.

Glad I found this forum!
-John

Anscojohn · Dec 18, 2009

My exposures with the 67s I have are rarely that short. Of course, I rarely makes 5x7s. Also, mine is the color head with diffusion.

The various piece of advice seem to be correct, though. One thing to check is the ensure the proper bulb is in the machine.

I had a buddy who used the spray kind of window frosting on one of the condensor lenses to attentuate the light.

ic-racer · Dec 18, 2009

JohnMilleker said:
Thank you all. IC, Great calculation on the exposure time. Though there goes the possibility of using my 2,4,8 stop ND Cokin filters in a pinch.

You have these; good!
Remember the density and 'stop' and 'factor' are all different. So, density of 0.3 is a 1 stop change is a factor of 2, etc...

Try your 2 stop filter and see what you get.

JohnMilleker · Dec 18, 2009

Thanks John, I'm going to play with aperture to see about dropping the light down another notch. The PH140 bulb was the previous owner had in it, so really - its possible it might be the wrong one. I'll look at lower wattage bulbs if I can't rectify the problem. No manual, but keeping an eye out on the popular auction site for one.

Window frosting? Very interesting. With that thought parchment paper jumps in my head as a possibility too?

IC - Thanks for clearing that up, I'll give it a try next time I print. Have a few different things to experiment with!

fotch · Dec 19, 2009

If no electronic circuits are involved, just the light bulb, you could wire in a dimmer switch or use an Variable Transformer (Variac). You could then reduce the light output. Just a thought.

JohnMilleker · Dec 30, 2009

Fotch, the only problem I see in a dimmer is repeatability. Especially if it's a simple analog potentiometer. But, still a good way to go if all else fails.

Update:
Received a new stock of 5x7" paper over the weekend and I ran another test last night with an Ilford #3 Variable Contrast filter, blocked off strips at 3 seconds each. The last strip (3 seconds) was perfect, everything else was pure black. On different paper (RC Graded #2 Glossy) too. Looks like I may be going that ND route but I really don't want to.

Tonight if I get time I'm going to see if I can get any solid readings on my light meter and find a good set of numbers that correspond with my findings. I'll also get that ND in there and see if I can finally get up to 10-15 seconds.

-John

fschifano · Dec 30, 2009

Click here and scroll down to where it says "Sun 85 & Neutral Density Filters." The first 4 items are what you want for ND filters. I'd suggest getting a sheet each of N.15 (1/2 stop) and N.3 (1 stop). They're cheap at about $6.50US each for a 20x24" sheet. Adorama and B&H in NY carry them, but I'm sure you can find someplace locally to source the product. Cut them up into whatever size you need to fit into your filter drawer. They're designed to be placed in front of high intensity lights used in film making so they can take the heat, and the neutral density ones have no color shift. I use them in a little Omega B600 that's too bright when I make small prints. They work great. If you need more density, they can be stacked and combined with your usual VC filters. Beats the heck out of using ND filters below the lens.

JohnMilleker · Dec 30, 2009

Frank, that's perfect. Thanks for your information - I didn't want to do any ND's between my negative and paper for sure, I want the best image quality possible. My Cokin plastic ND's I was a little worried about warping plus they're a little magenta on the color shift side - if I do go to Vari-Contrast paper I don't want that to be an issue.

One of each gel will be here tomorrow. Actually surprised I didn't think about the Cinegels, I have White Lightning strobes in my studio and I can blast studio gels all day without worrying about any heat damage.

-John

fschifano · Dec 30, 2009

John Koehrer said:
I'm guessing you're using a 50mm lens. You can also increase exposure times by using a longer lens(80/90/100mm)and also have more room between the head & base board to burn & dodge.

The head height doesn't change the exposure. The degree of enlargement does. Make the same size print at the same aperture with two different focal length lenses and the exposures will be very, very close. If the longer lens needs a lot of bellows extension, that will lengthen the exposure time over the shorter lens. There are other variables to consider like the efficiency of the lens coatings and the condensers, if applicable, etc., that also have an effect.

JohnMilleker · Jan 6, 2010

With your help I finally worked through it. The Rosco gels worked like a charm.

My 8x10 enlargement times are now up between 10 and 14 seconds with a 1 stop ND.

Thanks everyone!

jmal · Jan 9, 2010

Something sounds off with the bulb to me. Those are very short times. I used to feel I had short times with 15 second exposures, so I switched paper. I find that warm tone papers are generally slower than neutral papers, FB slower again than RC, and Foma FB slower yet again (and very good, too).

Roger Pellegrini · Jan 17, 2010

You can switch to a PH 12 or PH 11 bulb. BTW, do you have a heat absorbing glass plate in there? They make them for the Omega but I am not sure about the Beseler.

Enlarger too hot, which filters? (Bessy 67)

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