Review of Ilford MGRC V

pentaxuser

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Brian as others have stated the paper is a stop faster so a print of a scene on MGIV that takes10 secs will only take 5 secs on MGV so yes the new exposure time works against you. If at f16 or f22 you haven't got enough time for dodging and burning you might need to either lower the wattage of the bulb or introduce ND in some way

It sounds fro what you are saying that the blacks are blacker but yet the greys are washed out. These two things seem irreconcilable so this puzzles me. Another difference is that the speed of the paper means that you do not need to double the exposure for grades 4 and 5 - there is only a small increase in exposure needed. If you are using these two grades then doubling exposure would lead to overexposure which might explain the "harsher " blacks but not the washed out greys

pentaxuser
 

Mick Fagan

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Brian, probably the easiest way to get longer enlarging times, is to add a neutral density (ND) filter to the lens. Not the best thing, but certainly doable. Using ND filter(s) could allow you to add at a minimum 1 stop of time and more than likely 2 - 3 stops of time.

I looked up that enlarger, it appears to have a filter drawer above the lens and negative stages, but you do need to remove a cover that seems to need a screwdriver to lever off. If you have a filter drawer, I would use that, rather than having filters under the lens.

You may be able to find a ND filter that can go above the negative stage, that would be my preference.

If you have the colour head version of that enlarger, then let us know as you can dial in ND via the colour head.

Mick.
 

Brian Stater

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Hello Pentaxuser, hello Mick

Many thanks for your replies, both are really helpful!
I have found an email address for Kaiser and will see if I can get their thoughts too. An ND filter, suggested by you both, sounds a good idea.
Pentaxuser also mentions reducing the wattage of the bulb, which in this case is a 75W, with a screw-in fitting. I've scoured the internet, but can't find a lower enlarger bulb...though the thought occured that maybe I could fit a a dimmer switch. Any thoughts on that?

Thanks again

Brian
 

pentaxuser

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I am not familiar with Kaiser enlargers but a screw-in suggests an Edison screw. There are two screw systems. The ES and the SES which is the small Edison screw. Just looking at ScrewFix there seems to be bulbs, all LEDs which are very low wattage of course but are the equivalent of as low as 40W.

pentaxuser
 

Brian Stater

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Yes, it has a standard Edison fitting (the thread is about 25mm in diameter, I think it's designated E27).
Do LEDs come with this thread?
Also, I can get a domestic opal 60W bulb with this fitting....I wonder if that would be worth a go, though I guess it wouldn't have the intensity of a proper enlarger bulb
Brian
 

Lachlan Young

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Is the filter drawer above or below the condensers? Been years since I had anything to do with Kaiser enlargers.
 

pentaxuser

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Well a 60W would reduce the power by a fifth so 80% as powerful as a 75W I understand that a lot of domestic bulbs have writing on the top of the bulb which as I understand things is something to avoid. Presumably a 60W reduces the exposure time by 20% so a 10 sec exposure at 75W and f8 becomes 12 secs at 60W so doubling that each time for the next f stop upwards you might be close to what you need for dodging but if you are already at f22 with under-the-lens filter and you are still well short of enough time for dodging and burning then all a 60 W bulb is going to give you is 20% of this not enough time

What at are you getting at 75W at say f16 in terms of exposure and does this figure include the increase that the under-the-lens filter requires? I take it that at 5x7 prints these are from 35mm negs and the max f number on your lens is f22? My 50mm lens for 35mm negs only goes to f16 but my 80mm for medium format negs does go to f22. It might be worth swapping your 50mm lens for a 80mm but it sounds as if a 75/80 mm lens is the one you are using.

pentaxuser.
 

Brian Stater

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Yes, dead right. I'm printing from 35mm negs and the max f-stop on my lens is f22. I only have times for exposure with the filter in place....at f22 we're talking 12-15 seconds, at f16 and f11, of course, far briefer.
I think I'll put in the dometic bulb and see what happens....but all this does seem a big drawback with the Mark V paper....still, I'd like to crack this!
Brian
 

pentaxuser

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Looks like a ND filter might be the only real solution. A 20 % reduction in your times above is only 3 secs. My only experience is with a Durst dichroic head and I have a 75W bulb that if I could dial in f22 and with an under-the-lens filter would give me certainly 30 secs at least . It's a bit of a head scratcher why f22 gives such short times - not that this is immediately relevant to your problem.

pentaxuser
 

Brian Stater

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Yes, you may be right. I emailed Kaiser this afternoon asking if they have any thoughts on the problem and, specifically, if they can supply an ND filter. We'll see what they say (if they reply).
Thanks again for your help
Brian
 

Lachlan Young

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Brian Stater said:
The filter drawer is directly below the bulb, therefore above the condensor.
Brian
Click to expand...

I'd possibly look into getting a piece of lighting diffusion material (theatre/ film/ TV suppliers sell the heat resistant stuff) and placing it either above the condenser (to cut transmission) or under the condenser (to cut contrast by effectively making it a diffusion enlarger - it'll also cut light output too).
 

logan2z

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Brian Stater said:
Yes, you may be right. I emailed Kaiser this afternoon asking if they have any thoughts on the problem and, specifically, if they can supply an ND filter. We'll see what they say (if they reply).
Thanks again for your help
Brian
Click to expand...

If you want to use an ND filter to reduce the enlarger's light output then I'd pick up a sheet or two of Rosco Cinegel:

https://www.bhphotovideo.com/c/product/44186-REG/Rosco_RS340311_3403_Filter_Rosco.html

It comes in a variety of densities, is dirt cheap, and easy to cut to fit a filter drawer. I use it occasionally to combat short printing times with my Beseler 23CII. Works great.
 

Brian Stater

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Dear All
Here's a reply, received today from the technical support people at Kaiser.
It confirms a great deal of what Photrio members have suggested.
Thanks for your help and advice
Brian

Dear Brian,
As we had until now, no feedback beside customers of the new paper,
we have only the option to use a grey filter in front of the lens or a
grey filter in the lighting heads filter drawer:
http://www.kaiser-fototechnik.de/en/produkte/2_1_produktanzeige.asp?nr=4448

Maybe a dark glass grey filter in the drawer could be a solution...
A plastic filter would be melting due to the heat.

We have no idea, why Ilford has decided to increase the papers sentivity.

The market does not offer an opal bulb with lower wattage. If you would
use a dimmer, the color temperature would get more warmer, which can
change the papers gradation. Maybe you can test this, if it works for you.

Freundliche Gruesse / Best regards
i.A. Andreas Haerlin
Techn. Support
 

pentaxuser

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Brian, unless there is something about a LED bulb that makes it unsuitable per se for printing then the market, in the U.K. at least, does offer lower wattage frosted ( opal by any other name?) bulbs. I just Googled Opal LED bulbs in ES and it came up with several companies. One such bulb was the equivalent of 40 W which is nearly half the power of your 75W so should give nearly twice the exposure time.

Maybe those who know more about LED bulbs will comment on their suitability for printing B&W. The only drawback to the early low energy and wattage bulbs was their warm up period but LEDs are instant as far as I am aware

pentaxuser
 

MattKing

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For variable contrast paper, the discontinuous colour spectrum of LED bulbs adds complexities that are likely to vary between types of bulbs.
 

pentaxuser

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MattKing said:
For variable contrast paper, the discontinuous colour spectrum of LED bulbs adds complexities that are likely to vary between types of bulbs.
Click to expand...
Thanks Matt. Three questions if I may1) Are there any LED bulbs that are suitable for VC paper? (2) What are the effects on VC paper? (3) Are these effects the same each time such that once you have worked out the effect you can compensate for or is sit the case that currently the effects vary continuously such that no two prints exposed under the same negative and with the same bulb will ever be the same?

Thanks

pentaxuser
 

MattKing

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1) almost certainly - it is just difficult to say which ones;
2) depends on the bulb;
3) changing the filtration is where unexpected results come from.
Incandescent (including halogen) bulbs emit a continuous spectrum - peaks and valleys, but no gaps.
LED (and fluorescent) bulbs emit a spiky spectrum - peaks, valleys and gaps. Various techniques are applied to smooth them out, but if a gap happens to coincide with a part of the spectrum that the variable contrast paper is responsive to, you may end up with unpredictable results.
One partial indication of suitability is a high (90+) CRI (colour rendering index) for a bulb, but even that isn't a guarantee, because those numbers are oriented toward human vision, not the response of photographic darkroom materials .
There is a tremendous amount of change that has happened and is still happening with LED lighting technology. Tune in again soon.
 

ProfessorC1983

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pentaxuser said:
Are there any LED bulbs that are suitable for VC paper?
Click to expand...
MattKing said:
1) almost certainly - it is just difficult to say which ones;
Click to expand...

I ran into this very issue recently with MGRC. In seeking an LED bulb to replace an Omega 75W incandescent in my B600, I threw in an Ikea Ryet 10W bulb (1000 lumen, 2700K) I had lying around. Seemed to work great, but had somewhat faster exposure than the traditional bulb and restricted me to f/16 and smaller with manageable times. So I foolishly thought "well, since LED bulbs work fine, all I need to do is decrease the wattage" and picked up a Sunlite 80431 4W bulb (250 lumen, 2700K) reasoning that it would expose roughly 2 stops slower.

Wrong. If anything, the much smaller Sunlite bulb was 3+ stops faster. I completely blacked 4 or 5 sheets of the Ilford paper before figuring it out, assuming I had the wrong filter or aperture or time, but it was the bulb. Replaced it with the much bigger (and much more "visibly" bright to the eye) Ikea bulb and everything went back to what I expected.

I haven't bothered looking into the spectra of the bulbs to determine why the results were so unintuitive. There is a 4W / 400 lumen version of the Ryet I may try out to see if its spectrum is similar -- especially since I just noticed they are currently only $0.50 each from Ikea's website.
 

dkonigs

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It would certainly be interesting to actually measure and graph the spectra of all these bulbs. Unfortunately, the equipment for doing this is way too expensive for one-off usage.
 

pentaxuser

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Yes in the surface it doesn't make any sense. The lamps are measured in lumens which is light intensity and the lower the lumen number the lower the intensity is. As far as I know the potential problem with LED bulbs centres around whether they emit the full spectrum of light as a tungsten or tungsten halogen bulb might. What counts here is the CRI( colour reproduction index). There is at least one member here who uses an LED bulb successfully for B&W printing who experiences normal prints at all grades i.e. the bulb as far as he is concerned is no different from a tungsten one except for lower wattage and hence lower heat output which helps prevent negative "pop". I checked his bulb and it has a CRI rating of 80 and in fact most reputable bulbs have this rating. It is possible to find bulb with ratings of almost 100 - at a price - but unless the member's judgement of his prints is very faulty and he just cannot see any changes I have every reason to believe that for B&W printing LED bulbs do square the circle of lower power, cooler running and presumably longer life.

He too, if I recall correctly, noticed an increase in intensity compared to the equivalent wattage tungsten bulb but this was like for like and not as in Professor C1983's case a large drop in lumen rating but an increase in light intensity

I admit that is is quite a coincidence if it is not connected to a change in bulb but I strongly feel that for a 4 W to apparently increase the intensity of a 10W by several stops has to be connected to some other reason.

What springs to mind is that the 4 W bulb may have a much narrower beam of light so concentrates its light rather like a spotlight. Is this a possibility?

It's a head-scratcher of a problem in terms of a cause

pentaxuser
 

ProfessorC1983

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pentaxuser said:
What springs to mind is that the 4 W bulb may have a much narrower beam of light so concentrates its light rather like a spotlight. Is this a possibility?
Click to expand...

Very much so! In fact the Sunlite 4W bulb I used is marketed as a "floodlight" and listed as a 105-degree beam: https://www.amazon.com/gp/product/B01JIYYL1C

Sounds silly now, but it had not occurred to me that I'd need to take that factor into account in determining how it would affect the paper. I was thinking in terms of the lumen output only.
 

MattKing

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pentaxuser said:
What counts here is the CRI( colour reproduction index).
Click to expand...
Actually, CRI refers to colour rendering index, and isn't particularly reliable as an indicator of the suitability of an LED bulb for photographic purposes.
The way CRI is measured doesn't really correlate with the characteristics that light sensitive photographic materials require.
It isn't exactly the same, but this excerpt from the Wikipedia article on CRI in respect to Film and Video high CRI LED lighting gives a flavour for the problems:
Film and video high-CRI LED lighting[edit]
Further information: High-CRI LED lighting
Problems have been encountered attempting to use LED lighting on film and video sets. The color spectra of LED lighting primary colors does not match the expected color wavelength bandpasses of film emulsions and digital sensors. As a result, color rendition can be completely unpredictable in optical prints, transfers to digital media from film (DIs), and video camera recordings. This phenomenon with respect to motion picture film has been documented in an LED lighting evaluation series of tests produced by the Academy of Motion Picture Arts and Sciences scientific staff.[35]

To that end, various other metrics such as the TLCI (television lighting consistency index) have been developed to replace the human observer with a camera observer.[36] Similar to the CRI, the metric measures quality of a light source as it would appear on camera on a scale from 0 to 100.[37] Some manufacturers say that their products have TLCI values of up to 99.[38]
The owner of Modern Enlarger Lamps used to manufacture and sell some very interesting LED light source replacements for Omega D enlargers. His light source used specific, high end Cree bulbs. Sadly, he has stopped producing and selling them.


 

phreon

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I know this is a very late reply, but I just stumbled across this thread. It occurs to me you could get a "good enough for gov't work" idea of a given bulb's spectrum using a dSLR set to fixed white balance mode and a slow enough shutter speed to account for most LED lamps' flicker. If the camera itself doesn't give a useful enough color histogram, throw the image into your favorite image manipulation application and use the "eyedropper" tool to select the center of the light itself. You wouldn't get precise, absolute readings, but reasonable relative information.
 

Henning Serger

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Hello Brian,

so you have this enlarger:
http://www.kaiser-fototechnik.de/en/produkte/2_1_produktanzeige.asp?nr=4401

"Can accomodate filter drawer."

That would be your best solution: Upgrade your enlarger with the filter drawer above the negative carrier (it's optically the best solution, much better than any filter below the lens).
And than use the Cokin type A size (smallest size) ND 4x filter, which will most probably fit in that filter drawer perfectly.
At least that is the case with my (higher grade / more expensive) Kaiser enlarger, it fits perfectly. I am using this Cokin filter if I need longer exposing times, without sacrificing optical performance (by too much stopping down or filters under the lens).

Best regards,
Henning
 
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