Exposures Too Short

[Micky]

Hello all

I have recently purchased an enlarger - Durst D 659 condesnser type. I have been printing on some stander RC Ilford Multigrade IV papaer, as well as some older fibre paper that came with the enlarger. I plan on learning the art of printing on the Ilford multigrade, and once my ability improves, then try some more exotic papers. I am particularly keen to sink my teeth into dodgeing and burining. The problem that I have (or perceive) is that the exposures for my prints are too short. I did some 5x7 from 35mm exposures, and my times are about four seconds. I printed some 8x10 last night and the times were about two or three seconds with no filters, and four seconds with a multigrade 4, and bout seven seconds with a mg 4 and 2 at the same time. Are these times too short? I don't see how I can start to manipulate the prints in such a short time. The resulting prints look fine, except last nights prints seemed to seriously lack contrst, hence the two mg filters.

Any help or general advice would be greatly appreciated.

 

[d.reed]

Hello Micky,

Those are pretty short times. I try and aim for about 15 to 20 seconds if I know I'm going to need to dodge. The simplest way to extend your times is to stop down the enlarging lens from say f5.6 to f8, which would then require twice the time for exposure, since you double or halve exposure times as you go up and down the apertures.

Dana

 

[Micky]

Thanks Dana, I should have mentioned my f setting. I am using f11! I am reluctant to go higher, although I found that I had to go to f16 to get a usable time for some of my medium format prints. ideally i would like to rate at f8.

 

[Sirius Glass]

Micky,

My enlarger has a very bright setting for focusing, a high setting and a low setting for the bulb. I use the low setting almost exclusively. Does your enlarger have multiple bulb settings?

Steve

 

[bdial]

Can the enlarger accept a lower wattage bulb?
There is a lot to be said for working with the lens's sharpest aperture, but you also need to end up with usable exposure times. Stopping down is the simplest solution, if that doesn't work and you can't make a change with the bulb, then a neutral density filter will block some light and lengthen your exposures.
I'm not sure that MG filters are meant to be used in pairs, if you don't have enough contrast with a 4 then a 5 will get you as much as there is to get. If your prints are flat with a 5, then ether your negs are badly exposed, or your processing time is too short, or the developer is shot. If any of these is true it would be best to correct that condition then worry about exposure times.

 

[Micky]

I don't think that there is a brightness setting, but perhaps the globe is shot. The enlarger came with 11 spare globes, so I assumed the previous owner had the right ones.

 

[tkamiya]

I went through the same problem - except my problem was time being too long - when I re-started B&W photography. My typical exposure time was in the 20s of seconds at f/8.

Long story short, my problems were:
1) light bulb was too dim although it was 75 watts - replaced
2) negatives were too dark as a result of over-development

You *could* have opposite of my experience going on with yours.

IF you are printing MULTIGRADE paper without any filters, you tend to get about HALF the exposure time and equivalent of #2 grade filter contrast. If this is what you are doing, you can use #2 filter. Also, if you are printing 5x7 at f/8, remember, you get about 1/2 of time of printing 8x10.

After everything was sorted out, I am using #2 filter, f/8, and about 16 seconds of exposure time to print 8x10 from 35mm film. Typically, #2 is considered "normal".

 

[fotch]

What wattage or model is on the bulbs? I think it is suppose to be PH/211 or 75 watts.

Also, what developer, dilution, temperature, and time are you using?

 

[DWThomas]

I went through this a couple of years back after 30 years or so of not doing any B&W work. It seemed like the enlarging times were almost instantaneous. This was with an Omega B-8 with a 75 watt bulb. After discovering all three of my Nikkor enlarging lenses take the same filter size, I bought a 4x neutral density filter -- put it on for small (5x5 to 7x7) test prints, off for 11 x 11/14 and up -- problem solved.

I actually wrote up a question here on APUG inquiring whether enlarging papers have gotten faster over the years, as I don't remember this in the past, although that could have been due to my using a crude homemade enlarger back when.

 

[Micky]

ah a neutral density filter would definately slow things up, but I would prefer not to use one if there are simpler solutions. The globes are:

Philips Photocrescenta 250V 250W
E27 Type PF 607 E/51

There is a diagram on the side of the enlarger that says to use 100 to 200W globes.

 

[Sirius Glass]

ah a neutral density filter would definately slow things up, but I would prefer not to use one if there are simpler solutions. The globes are:

Philips Photocrescenta 250V 250W
E27 Type PF 607 E/51

There is a diagram on the side of the enlarger that says to use 100 to 200W globes.

Well 250W is greater than the upper limit of 100W to 200W. Find a dimmer bulb.

Steve

 

[Micky]

okay, i'll grab a couple tomorrow. how much difference does the wattage make to the exposure times? not sure whether to go for a 100W, 150W, or a 200W.

 

[Bob-D659]

Get both the 100 and 150. 100's will give you longer exposure times. I use both 75's and 150s, it all depends on the negative density and size.

One thing you can do if you don't like the all glass carrier is to make an insert out of sheet aluminum to replace the lower glass. If you do this and you want the autofocus to work, you will have to adjust the focus adjustment screws on the lens board. That single layer of glass does affect the lens to film distance. I also have a copy of the manual I can email to you, it is without pictures as that is the way I found the text cached by google.

 

[Micky]

Thanks for the advice Bob. So why would you change the bulbs for different negs densities? Would the only diffence, if you kept the 75W in all the time, be exposure time? Is there a disadvantage for longer exposure times apart from productivity? Sorry for all the noob questions!

Would I just get a square piece of aluminium, the size of the glass, and cut out a 36x24 square hole in the centre? If the aluminium was the same thickness as the glass, would that retain the autofocus as it is now? Thanking you in advance.

Regards
Ty

 

[fotch]

How much difference in light?
Following specs are from one of the sites.
7X or 3X times more Lumens.

PH/211 = 75w Color 3000°K, 1000 Lumens, 65 Hours
PH/212 = 150w Color 3050°K, 2300 Lumens, 100 Hours
PH/213 = 250w Color 3400°K, 7000 Lumens, 3 Hours

In addition, the more watts the more heat on the negative. Notice the 3 hour life expectancy of the 250 watt? Maybe that's why you got so many spares.

Hope this helps.

 

[Bob-D659]

The 75 watt just gives you longer exposure times and less neg warpage with a glassless carrier. With a high wattage bulb, a 35mm neg will warp downwards away from a top piece of glass.

With a piece the same thickness of the glass, you do have to adjust the three focus setting screws in the lens mount. In theory, a thicker piece of aluminum could move the negative upwards enough to compensate for the missing glass, but I'd have to do some digging in some books for the formula.

 

[Micky]

Okay, thanks guys. I've seen a 100 w 250v superba BC Krypton (G-250-100BC) mushroom globe for about $3. I'll give that a go.

 

[jeroldharter]

Don't rule out a ND filter. You are also printing small, 5x7 and 8x10.

If you are using the same format, e.g. 35 mm, much of the time, it might be worth buying B&W or Heliopan ND filters threaded for your enlarging lens for 2x, 4x, and 8x. I do that with no problems.

 

[Micky]

I will give these globes a try and see how it goes. I won't rule out the ND filter either, and actually I've got a spare 39mm B+W 2 stop in the cupboard which I just tried, but it is far too big.

 

[Janos]

Seriously, get a lower wattage globe. I suspect that you are using a condenser enlarger, which convert brightness very efficiently. Even a great enlarging lens will perform better around f8, and the heat from a 250 watter would have to be curling your negs, if in a glassless carrier, and/or without a cooling fan.
The 100 sounds about right. Also 15 to 20 secs is a good amount of time to work with.

 

[Micky]

yeah, it's a condenser. thanks all again for your help.

 

[Micky]

okay so I forgot that i had a Durst F30 in the shed. I looked inside and there was a 75W bulb. Tonight i did mostly 5x7s on RC Multigrade and my exposures were about 5 to 6 seconds with a number 4 filter @ f8. i would have liked a bit longer exposures, however this is slight improvement. looks like the nd filter may be a good option.

 

[RalphLambrecht]

...Also, what developer, dilution, temperature, and time are you using?

What does that have to do with it?

 

[RalphLambrecht]

okay, i'll grab a couple tomorrow. how much difference does the wattage make to the exposure times? not sure whether to go for a 100W, 150W, or a 200W.

Try a 100W bulb (not the clear tupe) and make sure to get one without lettering on the top.

 

[RalphLambrecht]

Seriously, get a lower wattage globe. I suspect that you are using a condenser enlarger, which convert brightness very efficiently. Even a great enlarging lens will perform better around f8, and the heat from a 250 watter would have to be curling your negs, if in a glassless carrier, and/or without a cooling fan.
The 100 sounds about right. Also 15 to 20 secs is a good amount of time to work with.

Now, I'm getting curious. Why are you calling these bulbs 'globes'?