Simple modern B&W 8x10 enlarger head

[Tin Can]

I noticed more viewers are looking at this section than DIY. So I posted here.

This is sort of DIY, but really it is just cutting a piece of foam core and laying a light source on top of it. No work involved.

See this link for my 5x7 version which is fancier but no better. (http://www.largeformatphotography.info/forum/showthread.php?110376-Hacking-8x10-and-11x14-enlarger-LED-head)

In the above thread I used a http://www.artograph.com/lightboxes/lightpad-920/ which works great and uses 4.6 watts at 120 vac. Operates at 5 degrees F above ambient. Which means no heat, no negative heat warp. Even after hours of usage, it never gets hot.

This 8x10 version uses the next size bigger, http://www.artograph.com/lightboxes/lightpad-930/ It also works great and uses a proportionally greater amount of power, clocking in at a whopping 7.4 watts at 120 vac. Exactly the same characteristics. 5 degrees F delta +.

The head's construction is very simple. I cut a 2 pieces of 3/16 black foam core to 15x17, glued them together and cut a 8x10 window in the right place, which is above lens center.

Then I just stacked the light box on top of the foam core, on top of the enlarger. Gravity works! I did gaff tape the power wire down so I don't pull the $117.00 light box off when raising the head.

Very tiny light leaks, which are easily sealed with gaff tape.

If anything, I have too much light at F8 with my 250mm Kodak Ektanon enlarging lens. I may add additional diffusion to lengthen printing times.. Focus is very bright. mine is installed on 10x10 Calumet enlarger chassis, that formerly used a Super ChroMega F Dichro II 1000 watt head.

As with the 5x7, I have a glass-less film carrier for 8x10 as seen in the pics. I bought it from a member here. I also have the traditional double glass carriers with one AN plate. But I prefer glass-less.

Obviously I cannot guarantee you will have the same results or even like my solution, I offer this up only as an idea. However, an idea I use. I do recommend you use only the above brand light pads, as I have tryed other brands that are not good. I have no connection with Artogragh. I bought mine on Amazon and have seen widely ranging prices, most likely depending upon school schedules.

I think one thing that makes these light pads work is the LED's are mounted evenly about the perimeter and the film size for each light pad is centered and away from the edges, allowing for even light.

If these light sources prove slightly uneven, I propose making an inkjet digital graduated ND diffusion filter/mask to even the light pattern, but I think that is unnecessary. I have posted proof of concept prints on the 5x7 thread and will be doing the same with this setup soon.

Another thing, I have noticed a one second delay in light on, but the LED is up to full strength right away, and the delay is consistent.

Lastly, Amazon will take it back if you don't like it. Try that with a used 8x10 head. I already threw my all boxes away...


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[Jac@stafford.net]

Excellent article and as a bonus we have a picture of Randy!

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[Tin Can]

That's his brother.

[Bill_4606]

Well done! Thanks for sharing. I'm going to check into the spectrum of the light source.
Bill

[bigdog]

Hmmm ...

I have an extra Beseler 4x5 in my garage and an Omega D5 I don't use. (This stuff just accumulates and nobody ever wants to buy them from me. Really! But, I digress ...)

A few years ago I passed up the chance to buy an 8x10 Durst, complete with neg carrier, for $200! I didn't buy it because it was huge! And heavy, and I couldn't see hauling it up the stairs to my second floor darkroom, if nothing else. (It remained available for a couple more years (see paranthetical insertion above) until another local photograph finally got it!)

I am a roll film guy, and if and when I go to sheet film, it will be 4x5, I'm sure, so I'm covered. But almost all the photographer friends I have in the area are large format shooters, and I wouldn't mind being able to print for them.

I will follow these threads ... :)

[Tin Can]

As a caution, I think this head is best used for 8x10 only. When masking down a large diffused light source we lose a lot of light and enlarging miniature negatives would take forever.

I do realize you said you were planning to print your friends LF negs.

I was just reading elsewhere that one user had a 25 minute printing time for a 35mm neg on a 5x7 enlarger!

Use the correct size enlarger for the job, they are everywhere, at least the 4x5 and under are.

[Ginette]

Thanks for sharing your experimentations Randy.
Do you ever open one of theses Lightpads to see what it is inside? I'm curious about if we can rebuit the light section illumination of the Lightpad 920 (removing some of the plastic casing) to fit exactly in the condenser housing of a Durst 5x7 : 8 1/2" wide x 7 3/4" deep by 2 1/8" high. The separators beetween the 2 condensers slots of the Durst 138 cannot be removed.
Also is the Lightpad 930 will enter in the Durst 8x10 condenser housing 14 1/4" x 14 1/4" square by 1 1/4" high but as the separators of the Durst 184 can be removed, the space available is 7" high.

I should buy one and experiment myself but it is a lot more expensive here in Canada. In fact, I have a lot of Aristo coldlights for my need in both sizes. But I look to donate some Durst 138 locally (a Photo Club still have darkroom here in Montreal) and the option of the condensers and the LED head will be nice.

Thanks for the info.

[Tin Can]

Sorry, I have no desire to take them apart, I leave destructive testing to my brother, he seldom puts things back together...

They don't have external screws and seem to be folded aluminum put together by machine. That silver is extruded aluminum.

As I have stated, I think these work a little better because we use only the center of the light and not right to the edges.

Experimentation is never free, we always pay with time or money.

I bet my brother could sawzall any enlarger to fit with these heads. :)

ymmv

[Tony Lakin]

Thanks for the article, very interested until I found the lightbox in the UK at about double the US price:mad:

[Tin Can]

One day I will hand deliver one, if I get to watch the TT. :)

[Ginette]

Sorry, I have no desire to take them apart, I leave destructive testing to my brother, he seldom puts things back together...

They don't have external screws and seem to be folded aluminum put together by machine. That silver is extruded aluminum.

As I have stated, I think these work a little better because we use only the center of the light and not right to the edges.

Experimentation is never free, we always pay with time or money.

I bet my brother could sawzall any enlarger to fit with these heads. :)

ymmv

Thanks for the information about the construction of theses units, Randy, so it is not easy to modify. Can you tell me about the exact size, they give weirds measures online :

Is the Lightpad 920 fit into the 138 condenser space 8 1/2" wide x 7 3/4" deep by 2 1/8" high. I think no, when I look at the dimensions given online. (measures 8-3/5-Inch by 11-3/6-Inch) If the unit put in vertical way, the 7" neg will probably not be covered, right?)
Is the Lightpad 930 fit into the 184 condenser space 14 1/4" x 14 1/4" square by 7" high. Dimensions given online is very close to theses ones (measures 11-3/4-inch length by 14-3/5-inch !!!)

[Tin Can]

The links in my post go directly to the Artograph website, where the dimensions are clearly and correctly stated in both metric and US Standard.

The lighted portion is exactly as stated as are total external measurement.

I would allow 1/8" for fudge factor.

[mdarnton]

Randy, while you're playing with this thing, would you mind taking a meter reading up close, off the center. I'd like to know exactly how bright yours is, in comparison with a different brand that I bought. Mine gives EV 12 @ EI 100.

http://www.amazon.com/Huion-Ultra-thin-ADJUSTABLE-Illumination-Lifetime/dp/B00J0UUHPO
It sounds similar, including being slightly brighter around the perimeter, mostly top and bottom, but the center seems very even. I'm using it for copying negs with my digital camera and for 5x7 it's fine. I haven't tried it on 8x10. It seems like the worst of the brighter area may be beyond the film edges....

I had thought about putting it on the back of my camera, to make an enlarger as you have, but I'm not sure if it will be bright enough.

[Tin Can]

Sorry guys, these are now installed and I am not removing them for any more fiddling or measurements.

I might add, I taped them down with gaff tape to foam core, which works well but does not remove without damaging the foam core.

Then I need to cut new foam core and use more gaff tape, Oh, the expenses of experimentation!

As for the light output, I will have actual printing times soon with the 8x10.

The 5x7 link has real world printing times and examples.



I would use the metric sizes as they are mostly Chinese made.

I am on to to other tasks.




Randy, while you're playing with this thing, would you mind taking a meter reading off the center. I'd like to know exactly how bright yours is, in comparison with a different brand that I bought. Mine gives EV 12 @ EI 100.

[Ginette]

Randy, while you're playing with this thing, would you mind taking a meter reading up close, off the center. I'd like to know exactly how bright yours is, in comparison with a different brand that I bought. Mine gives EV 12 @ EI 100.

http://www.amazon.com/Huion-Ultra-thin-ADJUSTABLE-Illumination-Lifetime/dp/B00J0UUHPO
It sounds similar, including being slightly brighter around the perimeter, mostly top and bottom, but the center seems very even. I'm using it for copying negs with my digital camera and for 5x7 it's fine. I haven't tried it on 8x10. It seems like the worst of the brighter area may be beyond the film edges....

I had thought about putting it on the back of my camera, to make an enlarger as you have, but I'm not sure if it will be bright enough.

So the Lightpad 930 at 14 3/5" !! (= 370mm official size) exceed by 5/16" the Durst 184 condenser but your Huion unit, Mdarnton, look to fit :

The whole light pad dimension including black frame is 10-5/8" x 14" with diagonal of 17.7". The Illuminated is 9" x 12.5"

Keep posting about your results with this Huion unit if you try it on 8x10 enlarger.

[mdarnton]

Well, if someone else buys one of those boxes and doesn't mind pointing a meter at it, I'd be happy for the info. It will tell me if I should go ahead with what I have, or not.

[Tin Can]

I just added my reasons for not removing my setups below.

It's $117 from Amazon and returnable.

That's less than anything LF I have bought in years.

Where do you live? I am near the Western Blue Line.

Maybe you need to drop in...

That's an invitation. Bring your meter.



Well, if someone else buys one of those boxes and doesn't mind pointing a meter at it, I'd be happy for the info. It will tell me if I should go ahead with what I have, or not.

[mdarnton]

Thanks for the invite...I will do that at some point in the near future--I want to see your setup.
I'm on the lake, near Wrigley Field.

[Tin Can]

f8 is the sweet spot

[evan clarke]

Does this really work?

[Tin Can]

Yes it works, or I could be lying... Not!

The 4 images below show my first 3 prints. The 4th print was underexposed from erratic timer.

#1 is an overview of the three 16x20 Ilford MGIV RC prints done on this setup.

#2 Is a 15 second enlargement at f8 from a very dense 8x10 Ilford Delta 100 neg. No filter, straight print.

#3 Is a 4 second exposure also at F8, I estimate 90% black.

#4 Has a layer of 3mm Makrolon LD diffusion added between light source and negative also F8, 4 seconds and is light grey.

I see some corner falloff in both empty prints, I didn't notice it in the RL print.

I used a old Kodak 250 mm Ektanon enlarging lens which most likely caused the slight falloff. I will retest with a 300 mm Rodagon with the same settings and try F16 as well.

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[ic-racer]

Looks pretty good so far, but what is the reason for testing wide open? I'd stop down and minimize the lens hotspot and then see what it looks like.

[John Kasaian]

Thanks! This is intriguing.

[Tin Can]

I'm testing 2 stops from wide open at F8 as I believe that is the optimal sharpness of enlarging lenses.

I am going to try F16 shortly with a Rodagon 300mm.

stay tuned.



Looks pretty good so far, but what is the reason for testing wide open? I'd stop down and minimize the lens hotspot and then see what it looks like.

[ic-racer]

I'm testing 2 stops from wide open at F8 as I believe that is the optimal sharpness of enlarging lenses.

I am going to try F16 shortly with a Rodagon 300mm.

stay tuned.

Of course you can monitor your corner sharpness so you know how much to stop that lens down (without relying on any 'believe' ;) ), but un-even illumination is harder to detect when you don't know about the light source. I'd not go more open than f22 or f32 when testing a light source, or when printing for that matter.

[Tin Can]

Yes, I read on your Durst thread you use f22 or f32 with Rodagon 300mm.

How come many sources, such as Darkroom Cookbook advise 2 stops from wide open? Way Beyond Monochrome also says on page 441 optimal is between f5.6 and f11, that's f8!

I am no genius and try to follow good advice to save time.

I also want to start from worst case to better. I used to stop down my 4x5 to f22, but I have been studying more....




Of course you can monitor your corner sharpness so you know how much to stop that lens down (without relying on any 'believe' ;) ), but un-even illumination is harder to detect when you don't know about the light source. I'd not go more open than f22 or f32 when testing a light source, or when printing for that matter.

[analoguey]

This is a very useful thread, Randy. Thanks for starting it.

[ic-racer]

Yes, I read on your Durst thread you use f22 or f32 with Rodagon 300mm.

How come many sources, such as Darkroom Cookbook advise 2 stops from wide open? Way Beyond Monochrome also says on page 441 optimal is between f5.6 and f11, that's f8!

I am no genius and try to follow good advice to save time.

I also want to start from worst case to better. I used to stop down my 4x5 to f22, but I have been studying more....

We don't know the light falloff or MTF curve of your lens to know optimum aperture.
Extrapolating from known curves of other big enlarger lenses we can guess that light falloff gets better right up to minimum aperture.
We can also guess (based on known Componon-S 240mm findings) corner sharpness is poor under the grain magnifier wide open but gets tolerable around f22 to 32 with a 16x20 print. But we don't need to guess, you can check this yourself (you do have a Peak 1 grain magnifier, yes?)

Noting wrong with testing the lens at wider aperture but my hunch is your light source performs better than you show because the light falloff from the lens is hampering the results. If you are only interested in combined light source and lens performance that is fine too. In that case you can either make a center filter or just realize all prints will need a little edge burn (which is frequently the case anyway).

The Durst CLS 2000/1840 8x10 light boxes were perhaps the most well designed 8x10 diffusion sources ever made. Even with that in place, the physics of the lens produces a light falloff requiring an edge burn on most all prints.

I don't have the 240mm or 300mm light falloff curves (anyone??) but the 150 and smaller lenses all follow a similar pattern as shown:
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[Tin Can]

No filters were used on any lens or print. all lenses are excellent, clean, scratch free, no fungus, little dust.

Here are the Rodagon 300 mm results. Enlarged about the same on 16x20 Ilford MGIV RC. The 8x10 negative was shot with Rodenstock Sironar-N MC 360 mm f6.8 at f22 in perfect condition on heavy Linhof tripod, no vibration, Linhof Color Kardan 8X10.

#1 Overall shot, the 2 prints of my tools are flat, the grey print I dried face up and it is warped in the middle and reflecting light differently than the dried face down prints. Mistake.

#2 Middle grey exposed for 10 seconds f16 300 mm Rodagon. Falloff compared to the 250 mm Kodak lens is far less. Rodagon wins.

#3 Same old neg as yesterday, exposed for 60 seconds f16 Rodagon 300 mm. Definitely sharper off center than 250 mm Kodak Ektanon and less fall off. Rodagon wins.

#4 Same print from yesterday, exposed for 15 seconds f8 Ektanon. Same sharpness in center shown by reading the center book titles as Rodagon 300 mm, but obviously less sharp at edges reading text in the image extremes. Ektanon will be used for 5X7 negatives.

I realize all enlargements will have falloff from any lens, light source combination. It is the nature of the beast, the edges of a print are lit with 'rays' traveling farther. Basic.

I think the head has proved to me it will be useful for me. ymmv

I am happy and not chasing a magic bullet 8x10 head anymore. I can afford this.

Again a caveat, I only used the the Artogragh 930 (http://www.artograph.com/lightboxes/lightpad-930/) light panel, I am no longer experimenting with any other panel. Do your own testing and please post results.

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[ic-racer]

Thanks for posting your results.

[Tin Can]

I just tried 240mm Rodagon and it is obvious best lens for 8 foot vertical enlarger. I can fill 30x40 inch baseboard without crawling on the floor. I can enlarge to 20x24" without ladder. At 10% crop, printing to 20x24" I have lens to baseboard distance 33" and neg to lens 15". Good edge to edge with much better everything than my 250mm Ektanon.

Reading historic posts, many have same conclusion.

Save time and money, start with 240mm Rodagon. inho :)

[Drew Wiley]

Different focal lengths of lenses, different brands and configurations, and even significantly different typical working stops are ALL factors which dictate having diffusers ground for the particular circumstances likely to be encountered. I don't see any reason someone would want to use something as short as a 240 on 8x10 (the wider the lens the more falloff and the more oblique the angle of light, just like camera use), EXCEPT when limitations in headroom in relation to an intended degree of enlargment dictate it. Apples to apples, longer focal lengths are always preferable if you have a high enough ceiling or a horizontal enlarger. Since many people intend to print only black and white, it's easy enough to burn in your corners. In color printing there are often serious advantages to having an even field of illumination. Everybody serious knows this already. It's also easy enough, though a bit time-consuming, to customize diffusers if you have experience with the respective kinds of plastics. Otherwise, there are people who can do it for you.

[Tin Can]

Drew, I will not be doing color. Ever.

I have 300 and 360mm Rodagon. For now I will be happy printing portraits at 20x24" max with 240mm Rodagon. Edges are not an issue with my dark backdrops and centrally placed heads.

I do have future plans to extend upwards with simple extension box on top of my Fotar, with the goal of using longer lenses, also trying for 11x14 negative enlargements. I know the 360mm is only for max of 10x12, but once again for portraits, I can stretch it a bit, or go to a 480mm Ronar, even 600mm process lens

I have 4 more feet of ceiling for these 8' enlargers. Many things possible. I may also convert 15x15" copy camera to horizontal enlarger as I could then do very large murals. I have 35' darkroom length.

This is only beginning. I am almost 64, just learning this hobby.

Now I await my sitter for todays portrait. Shooting 8x10 Linhof Color Kardan on dolly. 1950's all the way. Ortho, Karsh wannabe.

[Tin Can]

Update. I found Costco selling for $50 a very similar lamp to this http://www.honeywellstore.com/store/products/honeywell-led-security-light-ma0201.htm same power and lumens.

Good for 5X7 and 6x17 negs, right now with one layer of Makrolon diffusion it has a lot of light on the base board.

So far just experimenting with it. It's cheaper than Artogragh and way more powerful, runs very cool, consuming a measured 42.5 watts.

It does require hard wire connections, not a wall plug.

More, when I have more.

[Luis-F-S]

I just tried 240mm Rodagon and it is obvious best lens for 8 foot vertical enlarger. I can fill 30x40 inch baseboard without crawling on the floor. I can enlarge to 20x24" without ladder. At 10% crop, printing to 20x24" I have lens to baseboard distance 33" and neg to lens 15".

Save time and money, start with 240mm Rodagon. inho :)

and I've said this how many times......................? L

[Tin Can]

and I've said this how many times......................? L

I wrote that a year ago.

What's your point?

OK, how many times?

[Luis-F-S]

Didn't see the post date.

[John Jarosz]

Are you using graded paper or VC?

How do you feel the paper (either) responds to the lightsource in terms of adjusting print contrast?

This is good stuff.

[Tin Can]

Are you using graded paper or VC?

How do you feel the paper (either) responds to the lightsource in terms of adjusting print contrast?

This is good stuff.

Currently I use VC paper, but have graded paper in stock. TBD

I find the Artogragh gives me 'good seat of the pants' contrast with below the lens filters. I have not done and most likely will not do formal testing.

I have not fully explored the Honeywell lamp. My first concern is hot spots which Makrolon is designed to attenuate. TBD

[Dave Ogle]

Very interesting. What a great idea. Maybe I missed this. Filtration? I guess under the lens filters. Or graded paper. I have a Omega F with color head. Just getting into 8x10 enlargements. Dave O

[Tin Can]

Yes I use under the lens filters but recently found 12x12 filters for above, right here in our wonderful FS threads. Now I need to make a filter drawer. Winter work.


Very interesting. What a great idea. Maybe I missed this. Filtration? I guess under the lens filters. Or graded paper. I have a Omega F with color head. Just getting into 8x10 enlargements. Dave O

[adelorenzo]

Yes, I read on your Durst thread you use f22 or f32 with Rodagon 300mm.

How come many sources, such as Darkroom Cookbook advise 2 stops from wide open? Way Beyond Monochrome also says on page 441 optimal is between f5.6 and f11, that's f8!

I am no genius and try to follow good advice to save time.

I also want to start from worst case to better. I used to stop down my 4x5 to f22, but I have been studying more....

In Ctein's Post Exposure (http://ctein.com/booksmpl.htm) book he tested most of the common enlarging lenses from 35mm up to 4x5 format. There is individual data for each lens but to summarize they were all sharpest closed down about one stop, and depending on the lens the minimum aperture was 2-3 stops closed down before diffraction affected the image.

Obviously this is just one set of data but I've been closing down 1 - 1.5 stops on all my lenses and been very happy with the results. If I have a thin negative I might go 2 stops. Like you said this agrees with what is found in Way Beyond Monochrome and other sources too.

I also consider the fact that most camera (taking) lenses are considered sharpest stopped down 1-2 stops from wide open, although there are always other considerations when shooting (like depth of field).

[Drew Wiley]

There are all kinds of enlarging lenses he never evaluated. That book was written quite some time back. But most typical enlarging lenses are engineered to work best a couple stops or so down, but this is relative to the recommended format, how well aligned you have things, how flat your paper actually is, blah, blah. Some really good enlarging lenses are better wide open than a grubbly one at any f-stop. It also depends on how much magnification the print involves. For example, I often print up to 20X24 FB silver prints from 8x10 using a 305 Apo Nikkor, and that degree of magnification is so modest that the eye can't even detect whether I used the lens at f/11 or f/45. But that concept backfires when I print seriously bigger than that, and want a faster, official enlarging lens instead. In such cases, I use a 360/5.6 El Nikkor (a beast, size-wise), and do religiously keep it around f/8 to f/11. In other words, there is no "one shoe fits all" formula.