OT - Flash Photography

[fred]

of lenses. The current Sony 7 and Panasonic LX 100 beat the Nikon on many counts.

asonic LX 100 on some things although you don't give a scale that you're me asuring against so it's pretty meaningless.

Now you're just being childish. My meaning is perfectly obvious. No doubt y ou'd like me to list them so you could cherry pick your way through them re futing the ones that suited. I have neither the time or the inclination for such a meaningless task

x 3 1/4 negatives ) Rolleifles and Rolleicord, Yashicamat 124G. Mamiya C330 all mostly used as a professional in wedding and portraiture. Had my own d arkroom. Developed all films and made countless prints.

nk I could claim a modest amount of experience in camera usage.

us out of hand dismissal of mirrorless cameras as being not fit for profess ional use.

ofessional will chose one depends on what he's intending to photograph or t he market.

Now you're repeating what I have previously said.

e was a Minolta about 14 years or so ago, has see rapid improvements. The t echnology is now maturing. Modern evfs are exceptionally good. The lenses a re the same as those used by the dslra, via adapters if necessary. The sens ors are the same if not better than the dslr ones. assuming Sony keep the best for themselves. Someone above claimed that 4k video was the equivalent to 200ASA which nonsensical statement might indicate the quality of some p eople in this discussion.

any way, especailly without mentioning whether it was 35mm or 70mm.

This is the statement made:

" Its 4k resolution, about as good as 200 ASA film was. "

There is no sensible relationship to be made betweem 4k video and film spee d

ered an excellent alternative to a standard dslr and that it has/is replaci ng the dslr in many markets.

More non sequiturs,

to do with competition with phone cameras.

No It has nothing to do with it. You go one to claim you have a Pro wanderi ng around with a 4D over his shoulder claiming that his clients would not a ccept him if he started shooting with a phone camera so how are you working out that the phone camera is replacing dslrs ?

at the moment he admits that what he's doing at the moment he coul,d do wit h a phone but tehy wouldn;t have employed him to take pictures with his pho ne.

phone can't do the things he's Nikon can.

A real pro will let his work speak for itself. If he is depending on his eq uipment to give him kudos he's a poor example of the breed.

nds a Rollei could produce excellent results for certain sports. The straig ht through viewfinder allowed on to observe the action outside the frame an d plan accordingly.

der but watching with the other eye.

Bollix you do. Perhaps with a 50mm lens but beyond that and you'd be cross eyed. Anyway this would not be easy while using the camera in landscaoe mod e unless your eyes are very far apart

which did have interchangeable lenses was really too big and clumsy for su ch work IMHO.

s use of 120 film.

yuo to use a difernt perspective other than eye level fotogrphy which is wh at most do.

More rubbish.

The TLR is not always used at waistlevel.

The amateur crouch (down on one knee) gives the same perspective as the wai st level finder.

One of the exclusive features of the mirrorless is the flip up/down/sideway s screen that many have.

35mm users claiming their larger film gave better results.

rged far greater than 25mm or half frame or 110

You're repeating me again

in turn is now being replaced by mirrorless.

Can we have some evidence of this please.

Perhaps in your neck of the woods.

Remains to be seen. Nikon and Canon are both reported to be cutting back on their dslr manufacturing side. The writing is on the wall.

Who knows what the future will bring.

[Fredxxx]

That's not true, there could be if film suppliers/manufacturers were brave enough to publish their film resolution at specified light levels. There are lots of claims of achievable no. of lp/mm but funnily I can never see numbers published for a film that is actually on sale.

One thing, that surprises me if you claim to have expert knowledge in the field, is one advantage not having a pentaprism and mirror combination, it unties the hands of lens designers, leading to simpler and more efficient lenses.

[whisky-dave]

I assume they would if that's what was required.

Perhaps because it's not that important or relivent to film, in the same wa y you don't see the grasin size mentioned when talking about high ISO in DL SRs it's called noise now. I don't remmebr buying HP4 or 5 or kodachrome ha ving a noise rating funny that. Perhasp because they didn't priduce noise.

which I don't, most is common sense and knowing a little bit about it.

.is one advantage not having a pentaprism and mirror

Lens designers have always strived to improve their designs. pentaprism and mirrors have nothing to do with that. most P&S and compact cameras didn;t have pentaprism and mirrors, but they also didn't have interchangable lenses.

[fred]

snip

Yes. The lens designer doesn't have to make allowance for the clearance required for the mirror. Lenses can be more compact and wide angles are simpler to make

[fred]

snip

way you don't see the grasin size mentioned when talking about high ISO in DLSRs it's called noise now. I don't remmebr buying HP4 or 5 or kodachrome having a noise rating funny that. Perhasp because they didn't priduce noise .

Grain size is dependent on the development procedure. Of course one doesn't hear grain size mentioned on dslrs. That because they don't have grain. Th ey have noise instead which is a different beast entirely. Equally film doesn't have noise as noise is a by product of digital process ing so how in heavens name would they have a noise rating.

As stated before the absence of the mirror box gives a lens designer much greater freedom in his design choices

But for the camera manufacturer the absence of the mirror box and pentapris m eliminates two of the most precise parts of an slr. One of the reasons ds lrs will eventually disappear. Once the evf reached satisfactory resolution any benefit of the mirror and pentaprism were gone.

Now one can see in the viewfinder a true representation of what will be cap tured. No more chimping to check the shot. Exposure and colour rendition ca n both be checked before pressing the shutter button. Workflow is much fast er now one doesn't have to keep checking the captured image. Faster 'motor' speeds can be achieved with continuous viewing as there is no mirror to fl ip up out of the way blocking the view.

[dennis]

That was me and if you think 200ASA film was any better than 4k video frames then show me one that is. I doubt if a 100 ASA film would actually be better than the 3840 x 2160 pixels of 4k video.

[Fredxxx]

That shows you ignorance of lens design. I can assure you that back working distance for the lens has a significant impact in lens design. Generally the closer you can get an element to the image plane, the better the lens in terms of simplicity and overall efficiency.

[Fredxxx]

Grain size and the probability of whether a grain is exposed or not does lead to a noisy looking photo. Noise in a photodiode is quantifiable and predictable. A grainy image has many of the same features, but where film has the further complexity of a non linear response. If there's the will it can be measured:

It seems we agree on some points.

[dennis]

8<

Oh, they did. and they produced different noise on the different layers. It was caused by interaction in the silver producing bigger grains in some light conditions than other so the noise would vary across the image as well as the colour and the exposure time.

Digital doesn't produce the same sort of noise, its just one pixel being more sensitive to heat than another and you can see it in low light. Of course if you are going to do low light stuff with digital you could always go the amateur way and cool the sensor to reduce the noise effects. You can find youtube videos on how to fit cold fingers to stuff like D50s if you want to try it.

Of course they do, the mirror makes you space the rear of the lens away from the sensor, that may not be the best way to design a particular lens, e.g. wide angles need more elements just to get the focus in the correct place when there is a 50 mm gap behind the lens. It would be far easier to make a 12 mm lens if the gap was about 10 mm which means no mirror.

Its apparent that something is happening with lens designs as camera manufacturers are removing the filters from the sensors to get better resolutions, or at least they are doing so on compact system cameras. If you are still using the old nikon and cnnon lenses designed for film then you don't want to remove the filter as it hides the poor performance of the lenses.

[whisky-dave]

I don;t needd to know about lensd desing niether do the majority of pros.

I can assure you that back

So what do yuo think any of these pros worry about a few cms of lens lenght.

It's the ameteuers that'll worry about such a thing NOT the pros. So it's not going to effect their choice of lens.

you realy think the above pros are going to ditch their DSLRs for a mirror-less camera that has a lens which is better "in terms of simplicity and overall efficiency." they aren't. That's teh thing aboyut pros they are ther to get a job done, if that means taking a lens that's a couple of cm larger that will do they job they will.

I have access to a fuji film HS10 30X zoom, that'd be great for all those pro sports photogrphers, wouldn't need that large grey lens that cost 5-10X the whole HS10 camera would they.

[Fredxxx]

For thermally generated currents becoming significant you need long exposure times such as those used in astronomy.

How long exposure times are you worrying about. I think I would be worrying about image stability first!

What filters are these? Aren't most attached to the image plane?

Aren't these filters flat pieces of glass? And close to the image plane? Yes they do have power, but usually considered negligible, or can be taken into account in the lens design.

[Davey]

I fixed that for you:

"I don't need to know about lens design, neither do the majority of pros."

Easy, really.

[Fredxxx]

Do you understand what the back working distance of a lens is, and how reducing this makes lenses more efficient and easier to design?

Do you believe that it makes the overall length of a lens any shorter?

[fred]

ASA refers to the light sensitive of film. Not directly comparable to 4K wh ich is a measure of resolution. The developing process will have enormous e ffect on the resolution of any film regardless of the ASA, though generally speaking the lower ASA rating the higher the resolution. I get what you ar e talking about just think the comparison poor.Generally speaking current s ensors outperform film.

[dennis]

Where do you think the noise comes from in image sensors then?

The ones they fit to some DSLRs to try and work better with old design lenses.

No.

Yes.

Well yes they can be but they weren't on all those old lenses so you had better make sure you buy new lenses when you buy your DSLR because the old ones don't know about the differences in image sensors and film.

[dennis]

They started to outperform film a few years ago, most 35mm film is only about 5 megapixels and has less dynamic range.

[Martin Brown]

Most of it these days is readout noise and a small amount of thermal Johnson noise which only becomes significant on long exposures. Early CCDs had problems with a warm corner near the readout amplifier and stray IR photons producing patterns on a 16s uncooled exposure. eg

Modern CCDs have much higher efficiency and lower noise than this early Kodak chip in the Dc120 which was amongst the first megapixel digicams.

They are doing it because sharpness sells and people don't seem to care about image quality beyond naive lines per millimetre benchmarks.

They are the infrared hot mirror blocking filter and anti aliasing filters to control the sharpness and make the Bayer demosaicing algorithm better behaved. If you remove the former you will end up with an out of focus mess since CCDs are sensitive out to around 1000nm and the optics will pass enough of it to put a blurry IR mess round points.

Rubbish. Old 35mm family lenses work perfectly well with modern CCDs as the paraxial approximation is better on the smaller sensor.

Many modern digital lenses will not illuminate a full 35mm frame (and use insane 35mm equivalent focal length marketing notation).

[Fredxxx]

Oh dear. Will this help?

What? Lenses are designed with the film or sensor size in mind. Why do you imply otherwise?

Most sensor sizes are smaller than film as per:

[Fredxxx]

In some circumstances, yes. However film has a logarithmic response and can cope with extremes of lighting conditions.

[The Natural Philosopher]

Mmm. I actually have spme pretty dierct experience of thios using te same lenses with first kodachrome 25 and 64, and then a Nikon 200.

I used to shoot a lot of 400 ASA and thats looks about as fuzzy as 2Mp cameras. I forget what te nikon 200 is, but its up around the kodachrome

64, as long as you lkeep the 'film speed' below 200 ASA.

The pisser is that the 75-200 crappo nikon £150 zoom is actually better than the angenieux 75-210 I have that cost near £750 new, years ago..lenses have certainly got better.