SLR lens conversion (crop?) and film body Question

[feriso]

Over the weekend I met up with a mate and found out that quite some years ago he got himself a Canon film SLR with a couple of lenses. Now the lenses he had were a 28-90 and 80-200mm Canon EF fit, so are these subject to the crop factor (hence 80-200 is actually 50-125 on my 500D?). The latter works fine with auto/manual focus on my 500D so I've borrowed it for my hols to have a play with.

Now like I said he got him self into SLR by getting a Canon 300v/x (I can't remember which) and after having a play with my 500D he's thinking about getting back into it, but obviously going digital. So, is his film SLR worth much? If so how much and where's the best place to sell. It's in immacualte condition and I think its done less than 100 shots with it (or not far off)

 

[Stuff]

Regarding the crop factor, it will actually give you extended focal length on a crop sensor.

This is how I see it, and I hope I'm not too far off

For example, an EF 85mm on an EF-S body equates to about a 130mm focal length, not less.

This image kinda shows it... The circular image is the whole image produced by the lens... Obviously it's circular, as are the lenses. The blue frame is a full-frame sensor, say, at 85mm, which will fill up whoever many pixels the sensor is.

The red frame is the crop sensor size, which will also fill up however many pixels it's sensor has. This would be the same as a full frame camera, but the resulted picture will be bigger and therefore have enhanced zoom.

I'd like confirmation this is correct though It seems logical to me though!

 

[Rojin]

You're getting the wrong end of the stick with the crop factor (to the OP). The 500D is a 1.6 crop, this means you multiply the focal length of the lens by 1.6 not divide. So 128-320 for the 80-200 lens.

Film cameras don't fetch a great deal to be honest. Have a look at the completed listings on the bay for an idea of price that people are paying.

 

[Zogger]

Yes, any lens on a crop body with a given focal length range has a 'higher' 35mm equivalent. e.g. an 18-55mm ef-s kit lens is equivalent to 28.8-86mm if it was on a film camera, even though it is made for a crop body (and wouldn't work).

Therefore if the 80-200 were placed on a crop body it would have an equivalent 35mm focal range of 128-320. This would be true of a lens produced specifically for a crop body as well with an 80-200mm range.

I guess you could look at it in the other direction and say the pictures produced by the film camera look how they would if you used a 50-125mm lens on a crop body. I personally tend to think in 'cropped' lengths anyway since I'm relatively new to it so 50mm on a crop body means a lot more to me than 50mm on film...

 

[feriso]

Thanks for correcting me on the crop factor, I wasn't sure which way round it went but now I know As for the film camera I'm sure I read some where about 'film being the new thing' again or is it just a passing fad for the young'uns

 

[feriso]

Looking at it, his camera might be worth sod all and he said he might sell that lens to me. How much is it worth then (the 80-200 EF fit one I've mentioned)

 

[Rojin]

Thanks for correcting me on the crop factor, I wasn't sure which way round it went but now I know As for the film camera I'm sure I read some where about 'film being the new thing' again or is it just a passing fad for the young'uns

It may be the new "thing" but that's probably due to the cheap cost of a film SLR and some of the cheap processing now available at the likes of Tesco and Asda. A 300x recently sold for £31 and a 300v for £9.99!

I recently bought an old Canon AE-1 Program which I having great fun with

 

[Rojin]

Looking at it, his camera might be worth sod all and he said he might sell that lens to me. How much is it worth then (the 80-200 EF fit one I've mentioned)

Last one on TP sold for £40. They make a bit more than that on the auction site.

 

[Andy90]

Erm, a 85mm lens on a crop factor camera is still an 85mm lens. You don't magically get an extra 0.6 magnification out of the lens.

What you get is a cropped image of the circle of light projected on the sensor.

So in this instance the field of view of a 85mm lens would be equivilent to the field of view of a 136mm lens on a full frame sensor.

Camelpaws picture above is the right idea. Its what the crop sensor or Full frame 'see's.

If you increased the red rectangle to the same size of the red rectangle you're zooming in on the pixels - but you're not increasing the reach of the lens.

Obviously if you took the shot from the same spot on a crop sensor camera with an 85mm lens and then again with a 136mm lens and a full frame sensor (megapixels remaining the same) you would find that the full frame sensor version would be more detailed since the lens fitted to it would have an extra 51mm magnification.

 

[Rojin]

If you increased the red rectangle to the same size of the red(blue?) rectangle you're zooming in on the pixels - but you're not increasing the reach of the lens.

You're not zooming in on any pixels, a crop body has the pixels it has in that area. It does increase the reach of the lens by proxy of the end product produced. Hence the popularity of crop bodies for wildlife etc.

So in this instance the field of view of a 85mm lens would be equivilent to the field of view of a 136mm lens on a full frame sensor.

Which is what you say here.

 

[feriso]

You're not zooming in on any pixels, a crop body has the pixels it has in that area. It does increase the reach of the lens by proxy of the end product produced. Hence the popularity of crop bodies for wildlife etc.

Do i read that as crops have a higher pixel density then (due to the smaller sensor?) or is that being a bit too general?

 

[bigredshark]

Obviously if you took the shot from the same spot on a crop sensor camera with an 85mm lens and then again with a 136mm lens and a full frame sensor (megapixels remaining the same) you would find that the full frame sensor version would be more detailed since the lens fitted to it would have an extra 51mm magnification.

Erm, excluding external factors (the increased photosite sensitivity and lower pixel density of full frame, resolving power of the lens etc) that's not true. If you had a full frame and crop sensor with 12MP each and identical performance, then you'd get the same result detail wise. There are differences in depth of field to account for too, but allow for those and there's no difference optically (the mechanics of a full frame sensor tend to mean they yield better quality but optically there's no advantage)

 

[Rojin]

Do i read that as crops have a higher pixel density then (due to the smaller sensor?) or is that being a bit too general?

This would depend on the camera in use, the 7D does have a high pixel density due to be being 18MP which is a lot more dense than my 1D3 with only 10MP (and it's also only a 1.3 crop!). There's plenty of argument for and against the high pixel density, the 7D took nice pictures though so that was good enough for me. Although it could be noisy even at lower ISO settings. Nikon seem to be favouring a lower MP count which provides better ISO performance, it'll be interesting to see what the D700 replacement brings when it is released.

 

[bigredshark]

This would depend on the camera in use, the 7D does have a high pixel density due to be being 18MP which is a lot more dense than my 1D3 with only 10MP (and it's also only a 1.3 crop!). There's plenty of argument for and against the high pixel density, the 7D took nice pictures though so that was good enough for me. Although it could be noisy even at lower ISO settings. Nikon seem to be favouring a lower MP count which provides better ISO performance, it'll be interesting to see what the D700 replacement brings when it is released.

Given's Nikon's hand down mentality, the sensor from the D3s I suspect - 12MP and fancy low light performance. Bear in mind Nikon have only one camera with more than 12MP still and I doubt they're going to come up with a D3x sensor at the D700 price point.

There arguments for an against pixel density but I think it's fairly widely accepted that the top end crop bodies (D300s/7D) are making the right compromise there and unless you need low light performance or ultimate quality they're good for occasions when reach matters...