What's the limit for maximum DOF?

e-steve said:
I was only giving some links on how DOF works because sometimes we can think that one setting is the key and if we just understood how it works a little we can make better decisions on what to adjust. I've gone for a year before not understanding the way something works, and then once I took the time to learn it it was so much clearer to me.

I think the OP actually understands it, but his initial wording of his question made me think he didn't understand the most important variables. He was really just asking what acceptable ISO and shutter speeds are (the true answer to this is just "it depends")
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English is not my first language so you are right Steve, I asked my question in a very non-logically way, and worse, I should have kept the DOF thing out of this and asked what the slowest acceptable shutter speed and maximum acceptable ISO is (like you say). But this has been answered now and I get it. I did read about the ISO400 limit elsewhere and wanted confirmation and that's why I started this topic.

Also, I didn't take the suggestions to read books or your links as "personal". Some other comments were made by someone else, not you, it sidetracked the discussion and that's why I mentioned it, but it wasn't about you.
 
Perhaps it is a language barrier, but your initial question confused not only myself but several others and led us to believe you were asking a basic question of photography, when in fact you were asking a very different question.

So I apologize that we misinterpreted your question and gave perfectly reasonable answers to the question you asked. Hopefully, now you have the answers to the actual question you intended to ask.
 
RieniO said:
I plan to buy more lights, yes. Am wondering how the new LED lamps compare to fluorescent lights.
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All depends on what you want to do with them. Right now I think the biggest factor is price between LED's and flourescents. You can pick up descent fluorescent bulbs now right at a hardware store. They have 6500K lights which are nice and bright and do well with the digital cameras. I use those but I am already starting to see consumer LED bulbs come. Right now I doubt the low priced consumer LED bulbs are useful at this point but I could be wrong. If you are talking about professional lighting kits than I do believe LED's are still much higher in price than the others. I think it is kind of silly that they are priced so high considering LED's cost per unit would have to be much cheaper than their going sale price to the consumer. Flourescent bulbs have come a long way in the past couple of years. You can get really bright flourescents for very low cost. I imagine the LED's would give you a hard light so you could cast shadows while the flourescents are soft and are not great for shadows. Just depends on what you need to do with them. You can pick up a 5 pack of 100W equivalent 6500K flourescent bulbs for $10 these days. Back when I went to school that just didn't exist for such a low price. So you can have a ton of light for cheap.
 
Perrone, even with a language barrier, I would have put that "that you have no understanding of DOF or rudimentary photography" in a different way. Yes I agree, I took that personally but again, I should have asked in a more understandable way. Apology accepted, thanks for the answers.
 
Nitsuj said:
All depends on what you want to do with them. Right now I think the biggest factor is price between LED's and flourescents. You can pick up descent fluorescent bulbs now right at a hardware store. They have 6500K lights which are nice and bright and do well with the digital cameras. I use those but I am already starting to see consumer LED bulbs come. Right now I doubt the low priced consumer LED bulbs are useful at this point but I could be wrong. If you are talking about professional lighting kits than I do believe LED's are still much higher in price than the others. I think it is kind of silly that they are priced so high considering LED's cost per unit would have to be much cheaper than their going sale price to the consumer. Flourescent bulbs have come a long way in the past couple of years. You can get really bright flourescents for very low cost. I imagine the LED's would give you a hard light so you could cast shadows while the flourescents are soft and are not great for shadows. Just depends on what you need to do with them. You can pick up a 5 pack of 100W equivalent 6500K flourescent bulbs for $10 these days. Back when I went to school that just didn't exist for such a low price. So you can have a ton of light for cheap.
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Are you using ordinary fluorescent tubes? I invested a huge amount in 4 photonbeard heads ($800 per head or so), they are like the Videssence heads you have in the USA. They require special, expensive tubes and they have electronics to increase the frequency to 6000 Hz or something, to avoid problems when working with fast shutter speeds. But when I shoot with 1/50s or 1/100s, I could use ordinary tubes? Do I understand that right? If this is true I can build a few myself.

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Look here for prices on "pro" fluorescent and LED heads:

http://www.foto-walser.biz/shop/Kategorie/422/Florescent_lights.htm

So my problem has been solved. I want larger DOF, for that I need more light, I am going to build my own fluorescent lights with 6500K tubes from the hardware store :-)

You see, if you don't ask, you might never know :-)
 
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I've been shooting a again today, this time I used 4 light heads instead of 3, and put my ISO on 800. I don't know what aperture I was shooting at because I am using a Novoflex Nikon/MFT adapter but I think I was shooting with about F8, with a Tokina 16-50mm lens most of the time on 24mm, giving me a DOF of 1 to 2 meters most of the time which was ok. I haven't been able to review the footage on a large screen yet because importing into FCP takes a few hours and we were starving so went for somthing to eat. I'll check tomorrow morning what the footage looks like.

But I definitely need more light and if Nitsuj is right that ordinary fluorescent tubes can be used, I will build a few heads myself using tubes like that.

Then on the other hand I was always taught that fluorescents switch off and on 50 or 60 times per second so if your shooting with a 1/50s shutter speed you would get dark frames from time to time. What I do know is that these energy saving bulbs which also use fluorescent technology, work at a much higher frequency.

O well I guess I just need to do a test shoot in a place that's totally and only being luminated by ordinary fluorescent tubes I guess....
 
How much DOF do you WANT? I've still not understood this in all these posts? A few cm, a meter, 20 meters? What?
 
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